PT36 retarder & other things
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08-23-2007, 03:44
Post: #11
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PT36 retarder & other things
I'm with you Shane on the annual tranny fluid change. I use Transynd and
change the spin on filter each time. I leave the sump rock catcher in place. On 23/08/07, sfedeli3 <sfedeli3@...> wrote: > > Hi All, > > My tranny reading is regularly 230 degrees. Of course, it could be > a faulty sending unit, but my engine oil temp is around the same too, > if not a little warmer. I would expect both oil sumps to be pretty > close in temperature and seem to recall the blue book indicating that > 200 to 250 was the normal operating temp for the Allison that I have. > In any event, I change the fluid annually. It's relatively cheap and > easy to do on the mid-80's PT models. You just need a BIG bucket. > Varying brands of tranny fluid have different flash points and > additives. I've been using Lubrication Engineers > [http://www.le-inc.com] 7500 MONOLEC® Power Fluid in numerous vehicles > for a number of years with great results and never smell burned fluid > when I drain. If you're really concerned about the tranny temps, or > drive the western Rockies, get a Jacobs Engine Retarder. > > Shane Fedeli > 85PT40 > Hershey, PA > > --- In WanderlodgeForum@yahoogroups.com > "davidkerryedwards" > > > > > I found this on another website: > > > > Why Atf Wears Out > > An automatic transmission creates a lot of internal heat through > friction: the friction of the > > fluid churning inside the torque converter, friction created when > the clutch plates engage, > > and the normal friction created by gears and bearings carrying their > loads. > > > > It doesn't take long for the automatic transmission fluid (ATF) to > heat up once the vehicle > > is in motion. Normal driving will raise fluid temperatures to 175 > degrees F., which is the > > usual temperature range at which most fluids are designed to > operate. If fluid > > temperatures can be held to 175 degrees F., ATF will last almost > indefinitely -- say up to > > 100,000 miles. But if the fluid temperature goes much higher, the > life of the fluid begins > > to plummet. The problem is even normal driving can push fluid > temperatures well beyond > > safe limits. And once that happens, the trouble begins. > > > > At elevated operating temperatures, ATF oxidizes, turns brown and > takes on a smell like > > burnt toast. As heat destroys the fluid's lubricating qualities and > friction characteristics, > > varnish begins to form on internal parts (such as the valve body) > which interferes with the > > operation of the transmission. If the temperature gets above 250 > degrees F., rubber seals > > begin to harden, which leads to leaks and pressure losses. At higher > temperatures the > > transmission begins to slip, which only aggravates overheating even > more. Eventually the > > clutches burn out and the transmission calls it quits. The only way > to repair the damage > > now is with an overhaul -- a job which can easily run upwards of > $1500 on a late model > > front-wheel drive car or minivan. > > > > As a rule of thumb, every 20 degree increase in operating > temperature above 175 degrees > > F. cuts the life of the fluid in half! > > > > At 195 degrees F., for instance, fluid life is reduced to 50,000 > miles. At 220 degrees, > > which is commonly encountered in many transmissions, the fluid is > only good for about > > 25,000 miles. At 240 degrees F., the fluid won't go much over 10,000 > miles. Add another > > 20 degrees, and life expectancy drops to 5,000 miles. Go to 295 or > 300 degrees F., and > > 1,000 to 1,500 miles is about all you'll get before the transmission > burns up. > > > > > > Kerry > > 82 FC 35 > > Denver > > > > > > --- In WanderlodgeForum@yahoogroups.com > "davidkerryedwards" > > > wrote: > > > > > > Those temperatures seem really high to me. I was looking at hose > temperature ratings > > > and fluid temperature ratings when I was redoing my power > steering. My recollection is > > > that standard hydraulic hose was rated to 250 degrees and the > expensive high > > > temperature hose was rated to 325 or 350. I think regular > transmission fluid was rated > > as > > > functional up to about 250 degrees and synthetics up to about 350. > These numbers are > > > from my memory, If anyone else has knowledge about the functional > temperatures of > > > transmission fluid, I'd like to know. I'd be quite concerned with > temperatures over 300 > > > degrees. > > > > > > Kerry > > > 82 FC 35 > > > Denver > > > > > > be sure to keep it below > > > > 320-330 degrees or you'll shorten the life of the tranny fluid > > > > greatly. Most commercial bus drivers have to change the tranny fluid > > > > every 50K miles when using the tranny retarder often. Mine > easily goes > > > > from 230 to 300 degrees when descending a steep off-ramp. One way to > > > > slow the heat is to engage the fan override and let the hydro > fan rob > > > > 25-30 horses from the engine and cool the tranny fluid a little > > > > quicker. On an off-ramp it does not make much difference, but on > the 3 > > > > or 4 mile grade, you can usually make it to the bottom under 320 > > > > degrees if you also use the service brakes along with the tranny > brake > > > > and fan to slow the coach down. > > > > Shane Fedeli > > > > 85PT40 > > > > Hershey, PA > > > > > > > > > > > > > > > > -- Rob, Sue & Merlin Robinson 94 WLWB [Non-text portions of this message have been removed] |
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08-23-2007, 03:46
Post: #12
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PT36 retarder & other things
Hey Shane:
Does your coach have a retarder temp gauge? Apples and oranges may be what is happening here.. My tranny temp runs 170 normal. My retarder temp runs 230 normal. Per my book the max temp for the retarder is 320. I cannot remember what it is for the tranny. The closer to normal, the better. Leroy Eckert 1990 WB-40"Smoke N Mirrors" Niceville, FL Royale Conversion ----- Original Message ----- From: sfedeli3 To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 10:31 AM Subject: [WanderlodgeForum] Re: PT36 retarder & other things Hi All, My tranny reading is regularly 230 degrees. Of course, it could be a faulty sending unit, but my engine oil temp is around the same too, if not a little warmer. I would expect both oil sumps to be pretty close in temperature and seem to recall the blue book indicating that 200 to 250 was the normal operating temp for the Allison that I have. In any event, I change the fluid annually. It's relatively cheap and easy to do on the mid-80's PT models. You just need a BIG bucket. Varying brands of tranny fluid have different flash points and additives. I've been using Lubrication Engineers [http://www.le-inc.com] 7500 MONOLEC® Power Fluid in numerous vehicles for a number of years with great results and never smell burned fluid when I drain. If you're really concerned about the tranny temps, or drive the western Rockies, get a Jacobs Engine Retarder. Shane Fedeli 85PT40 Hershey, PA --- In WanderlodgeForum@yahoogroups.com, "davidkerryedwards" > > I found this on another website: > > Why Atf Wears Out > An automatic transmission creates a lot of internal heat through friction: the friction of the > fluid churning inside the torque converter, friction created when the clutch plates engage, > and the normal friction created by gears and bearings carrying their loads. > > It doesn't take long for the automatic transmission fluid (ATF) to heat up once the vehicle > is in motion. Normal driving will raise fluid temperatures to 175 degrees F., which is the > usual temperature range at which most fluids are designed to operate. If fluid > temperatures can be held to 175 degrees F., ATF will last almost indefinitely -- say up to > 100,000 miles. But if the fluid temperature goes much higher, the life of the fluid begins > to plummet. The problem is even normal driving can push fluid temperatures well beyond > safe limits. And once that happens, the trouble begins. > > At elevated operating temperatures, ATF oxidizes, turns brown and takes on a smell like > burnt toast. As heat destroys the fluid's lubricating qualities and friction characteristics, > varnish begins to form on internal parts (such as the valve body) which interferes with the > operation of the transmission. If the temperature gets above 250 degrees F., rubber seals > begin to harden, which leads to leaks and pressure losses. At higher temperatures the > transmission begins to slip, which only aggravates overheating even more. Eventually the > clutches burn out and the transmission calls it quits. The only way to repair the damage > now is with an overhaul -- a job which can easily run upwards of $1500 on a late model > front-wheel drive car or minivan. > > As a rule of thumb, every 20 degree increase in operating temperature above 175 degrees > F. cuts the life of the fluid in half! > > At 195 degrees F., for instance, fluid life is reduced to 50,000 miles. At 220 degrees, > which is commonly encountered in many transmissions, the fluid is only good for about > 25,000 miles. At 240 degrees F., the fluid won't go much over 10,000 miles. Add another > 20 degrees, and life expectancy drops to 5,000 miles. Go to 295 or 300 degrees F., and > 1,000 to 1,500 miles is about all you'll get before the transmission burns up. > > > Kerry > 82 FC 35 > Denver > > > --- In WanderlodgeForum@yahoogroups.com, "davidkerryedwards" > wrote: > > > > Those temperatures seem really high to me. I was looking at hose temperature ratings > > and fluid temperature ratings when I was redoing my power steering. My recollection is > > that standard hydraulic hose was rated to 250 degrees and the expensive high > > temperature hose was rated to 325 or 350. I think regular transmission fluid was rated > as > > functional up to about 250 degrees and synthetics up to about 350. These numbers are > > from my memory, If anyone else has knowledge about the functional temperatures of > > transmission fluid, I'd like to know. I'd be quite concerned with temperatures over 300 > > degrees. > > > > Kerry > > 82 FC 35 > > Denver > > > > be sure to keep it below > > > 320-330 degrees or you'll shorten the life of the tranny fluid > > > greatly. Most commercial bus drivers have to change the tranny fluid > > > every 50K miles when using the tranny retarder often. Mine easily goes > > > from 230 to 300 degrees when descending a steep off-ramp. One way to > > > slow the heat is to engage the fan override and let the hydro fan rob > > > 25-30 horses from the engine and cool the tranny fluid a little > > > quicker. On an off-ramp it does not make much difference, but on the 3 > > > or 4 mile grade, you can usually make it to the bottom under 320 > > > degrees if you also use the service brakes along with the tranny brake > > > and fan to slow the coach down. > > > Shane Fedeli > > > 85PT40 > > > Hershey, PA > > > > > > > > > [Non-text portions of this message have been removed] |
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08-23-2007, 06:45
Post: #13
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PT36 retarder & other things
I wonder why the Allison manual says to not use the Jake and transmission
retarder together? The jake on my coach is exhaust. The tranny retarder is on the transmission. Ernie Ekberg 83PT40 Livingston, Mt ************************************** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour [Non-text portions of this message have been removed] |
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08-23-2007, 10:10
Post: #14
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PT36 retarder & other things
Shane,
Could you add a jacob brake and have both a retarder and a jake brake. Howard T., Sowega, 86 PT40 ----- Original Message ----- From: sfedeli3 To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 11:31 AM Subject: [WanderlodgeForum] Re: PT36 retarder & other things Hi All, My tranny reading is regularly 230 degrees. Of course, it could be a faulty sending unit, but my engine oil temp is around the same too, if not a little warmer. I would expect both oil sumps to be pretty close in temperature and seem to recall the blue book indicating that 200 to 250 was the normal operating temp for the Allison that I have. In any event, I change the fluid annually. It's relatively cheap and easy to do on the mid-80's PT models. You just need a BIG bucket. Varying brands of tranny fluid have different flash points and additives. I've been using Lubrication Engineers [http://www.le-inc.com] 7500 MONOLEC® Power Fluid in numerous vehicles for a number of years with great results and never smell burned fluid when I drain. If you're really concerned about the tranny temps, or drive the western Rockies, get a Jacobs Engine Retarder. Shane Fedeli 85PT40 Hershey, PA --- In WanderlodgeForum@yahoogroups.com, "davidkerryedwards" > > I found this on another website: > > Why Atf Wears Out > An automatic transmission creates a lot of internal heat through friction: the friction of the > fluid churning inside the torque converter, friction created when the clutch plates engage, > and the normal friction created by gears and bearings carrying their loads. > > It doesn't take long for the automatic transmission fluid (ATF) to heat up once the vehicle > is in motion. Normal driving will raise fluid temperatures to 175 degrees F., which is the > usual temperature range at which most fluids are designed to operate. If fluid > temperatures can be held to 175 degrees F., ATF will last almost indefinitely -- say up to > 100,000 miles. But if the fluid temperature goes much higher, the life of the fluid begins > to plummet. The problem is even normal driving can push fluid temperatures well beyond > safe limits. And once that happens, the trouble begins. > > At elevated operating temperatures, ATF oxidizes, turns brown and takes on a smell like > burnt toast. As heat destroys the fluid's lubricating qualities and friction characteristics, > varnish begins to form on internal parts (such as the valve body) which interferes with the > operation of the transmission. If the temperature gets above 250 degrees F., rubber seals > begin to harden, which leads to leaks and pressure losses. At higher temperatures the > transmission begins to slip, which only aggravates overheating even more. Eventually the > clutches burn out and the transmission calls it quits. The only way to repair the damage > now is with an overhaul -- a job which can easily run upwards of $1500 on a late model > front-wheel drive car or minivan. > > As a rule of thumb, every 20 degree increase in operating temperature above 175 degrees > F. cuts the life of the fluid in half! > > At 195 degrees F., for instance, fluid life is reduced to 50,000 miles. At 220 degrees, > which is commonly encountered in many transmissions, the fluid is only good for about > 25,000 miles. At 240 degrees F., the fluid won't go much over 10,000 miles. Add another > 20 degrees, and life expectancy drops to 5,000 miles. Go to 295 or 300 degrees F., and > 1,000 to 1,500 miles is about all you'll get before the transmission burns up. > > > Kerry > 82 FC 35 > Denver > > > --- In WanderlodgeForum@yahoogroups.com, "davidkerryedwards" > wrote: > > > > Those temperatures seem really high to me. I was looking at hose temperature ratings > > and fluid temperature ratings when I was redoing my power steering. My recollection is > > that standard hydraulic hose was rated to 250 degrees and the expensive high > > temperature hose was rated to 325 or 350. I think regular transmission fluid was rated > as > > functional up to about 250 degrees and synthetics up to about 350. These numbers are > > from my memory, If anyone else has knowledge about the functional temperatures of > > transmission fluid, I'd like to know. I'd be quite concerned with temperatures over 300 > > degrees. > > > > Kerry > > 82 FC 35 > > Denver > > > > be sure to keep it below > > > 320-330 degrees or you'll shorten the life of the tranny fluid > > > greatly. Most commercial bus drivers have to change the tranny fluid > > > every 50K miles when using the tranny retarder often. Mine easily goes > > > from 230 to 300 degrees when descending a steep off-ramp. One way to > > > slow the heat is to engage the fan override and let the hydro fan rob > > > 25-30 horses from the engine and cool the tranny fluid a little > > > quicker. On an off-ramp it does not make much difference, but on the 3 > > > or 4 mile grade, you can usually make it to the bottom under 320 > > > degrees if you also use the service brakes along with the tranny brake > > > and fan to slow the coach down. > > > Shane Fedeli > > > 85PT40 > > > Hershey, PA > > > > > > > > > ------------------------------------------------------------------------------ No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.12.2/966 - Release Date: 8/22/2007 9:05 AM [Non-text portions of this message have been removed] |
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08-23-2007, 10:25
Post: #15
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PT36 retarder & other things
Howard, you sure can. I have two verbal bids for a Jake Brake addition on my
8v92 DDEC II. $9,500 and $9,000. Non -DDEC systems may be slightly cheaper, around $6-8,000. I did not want to buy a new bus, I just wanted a Jake brake. lol Leroy Eckert 1990 WB-40"Smoke N Mirrors" Niceville, FL ----- Original Message ----- From: Howard O. Truitt To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 5:10 PM Subject: Re: [WanderlodgeForum] Re: PT36 retarder & other things Shane, Could you add a jacob brake and have both a retarder and a jake brake. Howard T., Sowega, 86 PT40 ----- Original Message ----- From: sfedeli3 To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 11:31 AM Subject: [WanderlodgeForum] Re: PT36 retarder & other things Hi All, My tranny reading is regularly 230 degrees. Of course, it could be a faulty sending unit, but my engine oil temp is around the same too, if not a little warmer. I would expect both oil sumps to be pretty close in temperature and seem to recall the blue book indicating that 200 to 250 was the normal operating temp for the Allison that I have. In any event, I change the fluid annually. It's relatively cheap and easy to do on the mid-80's PT models. You just need a BIG bucket. Varying brands of tranny fluid have different flash points and additives. I've been using Lubrication Engineers [http://www.le-inc.com] 7500 MONOLEC® Power Fluid in numerous vehicles for a number of years with great results and never smell burned fluid when I drain. If you're really concerned about the tranny temps, or drive the western Rockies, get a Jacobs Engine Retarder. Shane Fedeli 85PT40 Hershey, PA --- In WanderlodgeForum@yahoogroups.com, "davidkerryedwards" > > I found this on another website: > > Why Atf Wears Out > An automatic transmission creates a lot of internal heat through friction: the friction of the > fluid churning inside the torque converter, friction created when the clutch plates engage, > and the normal friction created by gears and bearings carrying their loads. > > It doesn't take long for the automatic transmission fluid (ATF) to heat up once the vehicle > is in motion. Normal driving will raise fluid temperatures to 175 degrees F., which is the > usual temperature range at which most fluids are designed to operate. If fluid > temperatures can be held to 175 degrees F., ATF will last almost indefinitely -- say up to > 100,000 miles. But if the fluid temperature goes much higher, the life of the fluid begins > to plummet. The problem is even normal driving can push fluid temperatures well beyond > safe limits. And once that happens, the trouble begins. > > At elevated operating temperatures, ATF oxidizes, turns brown and takes on a smell like > burnt toast. As heat destroys the fluid's lubricating qualities and friction characteristics, > varnish begins to form on internal parts (such as the valve body) which interferes with the > operation of the transmission. If the temperature gets above 250 degrees F., rubber seals > begin to harden, which leads to leaks and pressure losses. At higher temperatures the > transmission begins to slip, which only aggravates overheating even more. Eventually the > clutches burn out and the transmission calls it quits. The only way to repair the damage > now is with an overhaul -- a job which can easily run upwards of $1500 on a late model > front-wheel drive car or minivan. > > As a rule of thumb, every 20 degree increase in operating temperature above 175 degrees > F. cuts the life of the fluid in half! > > At 195 degrees F., for instance, fluid life is reduced to 50,000 miles. At 220 degrees, > which is commonly encountered in many transmissions, the fluid is only good for about > 25,000 miles. At 240 degrees F., the fluid won't go much over 10,000 miles. Add another > 20 degrees, and life expectancy drops to 5,000 miles. Go to 295 or 300 degrees F., and > 1,000 to 1,500 miles is about all you'll get before the transmission burns up. > > > Kerry > 82 FC 35 > Denver > > > --- In WanderlodgeForum@yahoogroups.com, "davidkerryedwards" > wrote: > > > > Those temperatures seem really high to me. I was looking at hose temperature ratings > > and fluid temperature ratings when I was redoing my power steering. My recollection is > > that standard hydraulic hose was rated to 250 degrees and the expensive high > > temperature hose was rated to 325 or 350. I think regular transmission fluid was rated > as > > functional up to about 250 degrees and synthetics up to about 350. These numbers are > > from my memory, If anyone else has knowledge about the functional temperatures of > > transmission fluid, I'd like to know. I'd be quite concerned with temperatures over 300 > > degrees. > > > > Kerry > > 82 FC 35 > > Denver > > > > be sure to keep it below > > > 320-330 degrees or you'll shorten the life of the tranny fluid > > > greatly. Most commercial bus drivers have to change the tranny fluid > > > every 50K miles when using the tranny retarder often. Mine easily goes > > > from 230 to 300 degrees when descending a steep off-ramp. One way to > > > slow the heat is to engage the fan override and let the hydro fan rob > > > 25-30 horses from the engine and cool the tranny fluid a little > > > quicker. On an off-ramp it does not make much difference, but on the 3 > > > or 4 mile grade, you can usually make it to the bottom under 320 > > > degrees if you also use the service brakes along with the tranny brake > > > and fan to slow the coach down. > > > Shane Fedeli > > > 85PT40 > > > Hershey, PA > > > > > > > > > ---------------------------------------------------------- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.12.2/966 - Release Date: 8/22/2007 9:05 AM [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] |
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08-23-2007, 10:40
Post: #16
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PT36 retarder & other things
I'm not Shane but I have an answer. That is how my bus is arranged. When I got
it the PO had disconnected the Jake. The Allison manual says not to use them together. Too much torque I guess. I don't know who added the Jake, maybe BB. I try very hard NOT to use them together. Mostly I use the jake out of town. However, it isn't as effective as the tranny retarder. But, no head generation either. Dick Hayden - '87 PT 38 - Lake Stevens, WA ----- Original Message ----- From: Howard O. Truitt To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 3:10 PM Subject: Re: [WanderlodgeForum] Re: PT36 retarder & other things Shane, Could you add a jacob brake and have both a retarder and a jake brake. Howard T., Sowega, 86 PT40 ----- Original Message ----- From: sfedeli3 To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 11:31 AM Subject: [WanderlodgeForum] Re: PT36 retarder & other things Hi All, My tranny reading is regularly 230 degrees. Of course, it could be a faulty sending unit, but my engine oil temp is around the same too, if not a little warmer. I would expect both oil sumps to be pretty close in temperature and seem to recall the blue book indicating that 200 to 250 was the normal operating temp for the Allison that I have. In any event, I change the fluid annually. It's relatively cheap and easy to do on the mid-80's PT models. You just need a BIG bucket. Varying brands of tranny fluid have different flash points and additives. I've been using Lubrication Engineers [http://www.le-inc.com<http://www.le-inc.com/>] 7500 MONOLEC® Power Fluid in numerous vehicles for a number of years with great results and never smell burned fluid when I drain. If you're really concerned about the tranny temps, or drive the western Rockies, get a Jacobs Engine Retarder. Shane Fedeli 85PT40 Hershey, PA --- In WanderlodgeForum@yahoogroups.com "davidkerryedwards" > > I found this on another website: > > Why Atf Wears Out > An automatic transmission creates a lot of internal heat through friction: the friction of the > fluid churning inside the torque converter, friction created when the clutch plates engage, > and the normal friction created by gears and bearings carrying their loads. > > It doesn't take long for the automatic transmission fluid (ATF) to heat up once the vehicle > is in motion. Normal driving will raise fluid temperatures to 175 degrees F., which is the > usual temperature range at which most fluids are designed to operate. If fluid > temperatures can be held to 175 degrees F., ATF will last almost indefinitely -- say up to > 100,000 miles. But if the fluid temperature goes much higher, the life of the fluid begins > to plummet. The problem is even normal driving can push fluid temperatures well beyond > safe limits. And once that happens, the trouble begins. > > At elevated operating temperatures, ATF oxidizes, turns brown and takes on a smell like > burnt toast. As heat destroys the fluid's lubricating qualities and friction characteristics, > varnish begins to form on internal parts (such as the valve body) which interferes with the > operation of the transmission. If the temperature gets above 250 degrees F., rubber seals > begin to harden, which leads to leaks and pressure losses. At higher temperatures the > transmission begins to slip, which only aggravates overheating even more. Eventually the > clutches burn out and the transmission calls it quits. The only way to repair the damage > now is with an overhaul -- a job which can easily run upwards of $1500 on a late model > front-wheel drive car or minivan. > > As a rule of thumb, every 20 degree increase in operating temperature above 175 degrees > F. cuts the life of the fluid in half! > > At 195 degrees F., for instance, fluid life is reduced to 50,000 miles. At 220 degrees, > which is commonly encountered in many transmissions, the fluid is only good for about > 25,000 miles. At 240 degrees F., the fluid won't go much over 10,000 miles. Add another > 20 degrees, and life expectancy drops to 5,000 miles. Go to 295 or 300 degrees F., and > 1,000 to 1,500 miles is about all you'll get before the transmission burns up. > > > Kerry > 82 FC 35 > Denver > > > --- In WanderlodgeForum@yahoogroups.com "davidkerryedwards" > wrote: > > > > Those temperatures seem really high to me. I was looking at hose temperature ratings > > and fluid temperature ratings when I was redoing my power steering. My recollection is > > that standard hydraulic hose was rated to 250 degrees and the expensive high > > temperature hose was rated to 325 or 350. I think regular transmission fluid was rated > as > > functional up to about 250 degrees and synthetics up to about 350. These numbers are > > from my memory, If anyone else has knowledge about the functional temperatures of > > transmission fluid, I'd like to know. I'd be quite concerned with temperatures over 300 > > degrees. > > > > Kerry > > 82 FC 35 > > Denver > > > > be sure to keep it below > > > 320-330 degrees or you'll shorten the life of the tranny fluid > > > greatly. Most commercial bus drivers have to change the tranny fluid > > > every 50K miles when using the tranny retarder often. Mine easily goes > > > from 230 to 300 degrees when descending a steep off-ramp. One way to > > > slow the heat is to engage the fan override and let the hydro fan rob > > > 25-30 horses from the engine and cool the tranny fluid a little > > > quicker. On an off-ramp it does not make much difference, but on the 3 > > > or 4 mile grade, you can usually make it to the bottom under 320 > > > degrees if you also use the service brakes along with the tranny brake > > > and fan to slow the coach down. > > > Shane Fedeli > > > 85PT40 > > > Hershey, PA > > > > > > > > > ---------------------------------------------------------- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.12.2/966 - Release Date: 8/22/2007 9:05 AM [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] |
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08-23-2007, 10:43
Post: #17
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PT36 retarder & other things
Thanks Leroy,
Howard ----- Original Message ----- From: Leroy Eckert To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 6:25 PM Subject: Re: [WanderlodgeForum] Re: PT36 retarder & other things Howard, you sure can. I have two verbal bids for a Jake Brake addition on my 8v92 DDEC II. $9,500 and $9,000. Non -DDEC systems may be slightly cheaper, around $6-8,000. I did not want to buy a new bus, I just wanted a Jake brake. lol Leroy Eckert 1990 WB-40"Smoke N Mirrors" Niceville, FL ----- Original Message ----- From: Howard O. Truitt To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 5:10 PM Subject: Re: [WanderlodgeForum] Re: PT36 retarder & other things Shane, Could you add a jacob brake and have both a retarder and a jake brake. Howard T., Sowega, 86 PT40 ----- Original Message ----- From: sfedeli3 To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 11:31 AM Subject: [WanderlodgeForum] Re: PT36 retarder & other things Hi All, My tranny reading is regularly 230 degrees. Of course, it could be a faulty sending unit, but my engine oil temp is around the same too, if not a little warmer. I would expect both oil sumps to be pretty close in temperature and seem to recall the blue book indicating that 200 to 250 was the normal operating temp for the Allison that I have. In any event, I change the fluid annually. It's relatively cheap and easy to do on the mid-80's PT models. You just need a BIG bucket. Varying brands of tranny fluid have different flash points and additives. I've been using Lubrication Engineers [http://www.le-inc.com] 7500 MONOLEC® Power Fluid in numerous vehicles for a number of years with great results and never smell burned fluid when I drain. If you're really concerned about the tranny temps, or drive the western Rockies, get a Jacobs Engine Retarder. Shane Fedeli 85PT40 Hershey, PA --- In WanderlodgeForum@yahoogroups.com, "davidkerryedwards" > > I found this on another website: > > Why Atf Wears Out > An automatic transmission creates a lot of internal heat through friction: the friction of the > fluid churning inside the torque converter, friction created when the clutch plates engage, > and the normal friction created by gears and bearings carrying their loads. > > It doesn't take long for the automatic transmission fluid (ATF) to heat up once the vehicle > is in motion. Normal driving will raise fluid temperatures to 175 degrees F., which is the > usual temperature range at which most fluids are designed to operate. If fluid > temperatures can be held to 175 degrees F., ATF will last almost indefinitely -- say up to > 100,000 miles. But if the fluid temperature goes much higher, the life of the fluid begins > to plummet. The problem is even normal driving can push fluid temperatures well beyond > safe limits. And once that happens, the trouble begins. > > At elevated operating temperatures, ATF oxidizes, turns brown and takes on a smell like > burnt toast. As heat destroys the fluid's lubricating qualities and friction characteristics, > varnish begins to form on internal parts (such as the valve body) which interferes with the > operation of the transmission. If the temperature gets above 250 degrees F., rubber seals > begin to harden, which leads to leaks and pressure losses. At higher temperatures the > transmission begins to slip, which only aggravates overheating even more. Eventually the > clutches burn out and the transmission calls it quits. The only way to repair the damage > now is with an overhaul -- a job which can easily run upwards of $1500 on a late model > front-wheel drive car or minivan. > > As a rule of thumb, every 20 degree increase in operating temperature above 175 degrees > F. cuts the life of the fluid in half! > > At 195 degrees F., for instance, fluid life is reduced to 50,000 miles. At 220 degrees, > which is commonly encountered in many transmissions, the fluid is only good for about > 25,000 miles. At 240 degrees F., the fluid won't go much over 10,000 miles. Add another > 20 degrees, and life expectancy drops to 5,000 miles. Go to 295 or 300 degrees F., and > 1,000 to 1,500 miles is about all you'll get before the transmission burns up. > > > Kerry > 82 FC 35 > Denver > > > --- In WanderlodgeForum@yahoogroups.com, "davidkerryedwards" > wrote: > > > > Those temperatures seem really high to me. I was looking at hose temperature ratings > > and fluid temperature ratings when I was redoing my power steering. My recollection is > > that standard hydraulic hose was rated to 250 degrees and the expensive high > > temperature hose was rated to 325 or 350. I think regular transmission fluid was rated > as > > functional up to about 250 degrees and synthetics up to about 350. These numbers are > > from my memory, If anyone else has knowledge about the functional temperatures of > > transmission fluid, I'd like to know. I'd be quite concerned with temperatures over 300 > > degrees. > > > > Kerry > > 82 FC 35 > > Denver > > > > be sure to keep it below > > > 320-330 degrees or you'll shorten the life of the tranny fluid > > > greatly. Most commercial bus drivers have to change the tranny fluid > > > every 50K miles when using the tranny retarder often. Mine easily goes > > > from 230 to 300 degrees when descending a steep off-ramp. One way to > > > slow the heat is to engage the fan override and let the hydro fan rob > > > 25-30 horses from the engine and cool the tranny fluid a little > > > quicker. On an off-ramp it does not make much difference, but on the 3 > > > or 4 mile grade, you can usually make it to the bottom under 320 > > > degrees if you also use the service brakes along with the tranny brake > > > and fan to slow the coach down. > > > Shane Fedeli > > > 85PT40 > > > Hershey, PA > > > > > > > > > ---------------------------------------------------------- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.12.2/966 - Release Date: 8/22/2007 9:05 AM [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] ------------------------------------------------------------------------------ No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.12.2/966 - Release Date: 8/22/2007 9:05 AM [Non-text portions of this message have been removed] |
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08-23-2007, 10:57
Post: #18
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PT36 retarder & other things
I don't know Ernie. It's arranged the same on mine. The Allison Operator's
Manual simply states not to use them together with no expansion on that. I did operate the bus using both at first until I got my hands on an Operator's Manual, no more. Maybe one of gurus can offer something. Dick Hayden - '87 PT 38 - Lake Stevens, WA ----- Original Message ----- From: erniecarpet@... To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 3:45 PM Subject: Re: [WanderlodgeForum] Re: PT36 retarder & other things I wonder why the Allison manual says to not use the Jake and transmission retarder together? The jake on my coach is exhaust. The tranny retarder is on the transmission. Ernie Ekberg 83PT40 Livingston, Mt ************************************** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour<http://discover.aol.com/memed/aolcom3\ 0tour> [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] |
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08-23-2007, 11:13
Post: #19
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PT36 retarder & other things
Here's what the Allison Operator's Manual says on page 18, in a Caution box at
the bottom of the page: "DO NOT OPERATE THE INPUT OR OUTPUT RETARTDER SIMULTANEOUSLY WITH AN ENGINE EXHAUST BRAKE. Extreme torque loads can be produced in the range section, damaging the transmission". Leroy may have some other information on this. I know he was looking into doing this very thing. Dick Hayden - '87 PT 38 - Lake Stevens, WA ----- Original Message ----- From: Richard Hayden To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 3:57 PM Subject: Re: [WanderlodgeForum] Re: PT36 retarder & other things I don't know Ernie. It's arranged the same on mine. The Allison Operator's Manual simply states not to use them together with no expansion on that. I did operate the bus using both at first until I got my hands on an Operator's Manual, no more. Maybe one of gurus can offer something. Dick Hayden - '87 PT 38 - Lake Stevens, WA ----- Original Message ----- From: erniecarpet@... To: WanderlodgeForum@yahoogroups.com Sent: Thursday, August 23, 2007 3:45 PM Subject: Re: [WanderlodgeForum] Re: PT36 retarder & other things I wonder why the Allison manual says to not use the Jake and transmission retarder together? The jake on my coach is exhaust. The tranny retarder is on the transmission. Ernie Ekberg 83PT40 Livingston, Mt ************************************** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour<http://discover.aol.com/memed/aolcom3\ 0tour><http://discover.aol.com/memed/aolcom30tour<http://discover.aol.com/memed/\ aolcom30tour>> [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] |
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08-23-2007, 11:15
Post: #20
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PT36 retarder & other things
At a guess, too much stopping power. Think about it this way: You have your
drivers turning freely, no brakes applied. They are in turn running the rear-end and the rest of the drive train back through the transmission and engine. Now imagine you have some ability to "clamp" down on that drive line at the engine, without producing excessive heat, to the point that you could actually stop it from turning. How much before you got to that point, with the wheels starting to slide, do you think you would potentially suffer damage to some portion of the driveline? Our Allison's can handle 500HP, but the combination of Jake and retarder is capable of more than 500HP of stopping power. Not enough to freeze the driveline unless you are on a slippery road, but you could come close. On 8/23/2007 at 6:45 PM erniecarpet@... wrote: >I wonder why the Allison manual says to not use the Jake and transmission > >retarder together? The jake on my coach is exhaust. The tranny retarder is >on >the transmission. > >Ernie Ekberg >83PT40 >Livingston, Mt |
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