PT36 retarder & other things

[erniecarpet@...]

Art, for those that have the transmission retarder, the build up of heat is
quite common. I know I have heard that watching those temps closely and
perhaps a lower gear going downhill really helps.
On the oil on the rear of the coach, mine does that, and I thought that my
coach was the only rust free coach around. Check your radiator fan motor and
see if it's leaking.

Ernie Ekberg
83PT40
Livingston, Mt




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[Non-text portions of this message have been removed]

[amweath]

Got back Monday eve. from the Montery Historic Auto Races. The Bluebird
performed almost flawlessly. I do have two concerns.

When coming down the grade into San Luis Obispo, I had the first occa-
sion to use the retarder. The grade is steep but short (2nd gear going
up). What was alarming was how fast the trans temp went up - maybe 25
degrees in 15 seconds of use. Is this normal? It does hold well though.

The other item was a light sheen of oil on the back of the coach when I
got home. I traveled about 800 miles. I can't imagine it coming from
the exaust - not a hint of smoking.

The races were quite an expirience. They featured the Indy Roadsters
from the mid-50s to the mid-60s among, of course, many other types.

Any insight into the two concerns is appreciated.

Art Weatherly
Riverside Ca
'85 PT36

[Leroy Eckert]

Retarder/Transmission temps.---My retarder temperature rises 30 degrees fairly
rapidly when in use. ie, from 230 to 260. Thereafter, there seems to be a slower
increase. I have not had mine over about 270. My tranny temp does rise but not
as rapidly. They both cool down fairly quickly after use.
Oil on back.---I am guessing in the absense of an engine oil leak it could be
blow by from the breather tube or the slobber tubes. I haven't experienced the
problem. My slobber tubes drop very little oil and extend to road level.
Leroy Eckert
1990 WB-40"Smoke N Mirrors"
Niceville, FL
Royale Conversion
----- Original Message -----
From: amweath
To: WanderlodgeForum@yahoogroups.com
Sent: Wednesday, August 22, 2007 4:24 PM
Subject: [WanderlodgeForum] PT36 retarder & other things


Got back Monday eve. from the Montery Historic Auto Races. The Bluebird
performed almost flawlessly. I do have two concerns.

When coming down the grade into San Luis Obispo, I had the first occa-
sion to use the retarder. The grade is steep but short (2nd gear going
up). What was alarming was how fast the trans temp went up - maybe 25
degrees in 15 seconds of use. Is this normal? It does hold well though.

The other item was a light sheen of oil on the back of the coach when I
got home. I traveled about 800 miles. I can't imagine it coming from
the exaust - not a hint of smoking.

The races were quite an expirience. They featured the Indy Roadsters
from the mid-50s to the mid-60s among, of course, many other types.

Any insight into the two concerns is appreciated.

Art Weatherly
Riverside Ca
'85 PT36





[Non-text portions of this message have been removed]

[sfedeli3]

Hi Art,

The tranny will heat up pretty quick- 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.
The thin sheen of oil is probably the result of a leaking hydraulic
fan hose or tranny hose somewhere. Check all of the big 1-1/2" hoses
going to the tranny and hydraulic fan motor. If you've never replaced
them, it may be about that time. I drove 200 miles a few years ago and
arrived to find my toad covered in oil from the hydraulic fan sump. As
is turned out, the supply line from the sump to the fan motor had
rubbed against a hose fitting and ruptured. Thank goodness for dawn
dish detergent. What a mess! The tranny cooling lines are under VERY
high pressure when you engage the tranny retarder. I'd have them
checked out ASAP or just replaced if you don't know how old they are.

Shane Fedeli
85PT40
Hershey, PA


--- In WanderlodgeForum@yahoogroups.com, "amweath"
wrote:
>
> Got back Monday eve. from the Montery Historic Auto Races. The Bluebird
> performed almost flawlessly. I do have two concerns.
>
> When coming down the grade into San Luis Obispo, I had the first occa-
> sion to use the retarder. The grade is steep but short (2nd gear going
> up). What was alarming was how fast the trans temp went up - maybe 25
> degrees in 15 seconds of use. Is this normal? It does hold well though.
>
> The other item was a light sheen of oil on the back of the coach when I
> got home. I traveled about 800 miles. I can't imagine it coming from
> the exaust - not a hint of smoking.
>
> The races were quite an expirience. They featured the Indy Roadsters
> from the mid-50s to the mid-60s among, of course, many other types.
>
> Any insight into the two concerns is appreciated.
>
> Art Weatherly
> Riverside Ca
> '85 PT36
>

[bbwlwb88]

Art, fast temperature increases are common when using the retarder.
In the 1984, 1985, and 1986 pushers the transmission fluid
temperature sensor location was not in the best position in those
Birds. I believe, in 1987, Wanderlodge engineers relocated the
sensor to a less sensitive position which was more accurate in
measuring overall transmission fluid temperature when the retarder is
activated.

If you are seeing an oily film on the front of your tow vehicle or
the rear of your coach it's probably a hydraulic oil leak or an
engine coolant hose leak. An engine oil leak is also a possibility.
Either way it's a warning sign not to be ignored. It's a good idea,
any time you are traveling, to check your coach and tow vehicle
periodically for signs of such leaks.

Royal Washburn
97WL43

In WanderlodgeForum@yahoogroups.com, "amweath"
wrote:
>
> Got back Monday eve. from the Montery Historic Auto Races. The
Bluebird
> performed almost flawlessly. I do have two concerns.
>
> When coming down the grade into San Luis Obispo, I had the first
occa-
> sion to use the retarder. The grade is steep but short (2nd gear
going
> up). What was alarming was how fast the trans temp went up - maybe
25
> degrees in 15 seconds of use. Is this normal? It does hold well
though.
>
> The other item was a light sheen of oil on the back of the coach
when I
> got home. I traveled about 800 miles. I can't imagine it coming from
> the exaust - not a hint of smoking.
>
> The races were quite an expirience. They featured the Indy Roadsters
> from the mid-50s to the mid-60s among, of course, many other types.
>
> Any insight into the two concerns is appreciated.
>
> Art Weatherly
> Riverside Ca
> '85 PT36
>

[Rob Robinson]

Hi Shane. I've always thought it was best to keep the tranny temp at or
below 200F. I guess I have been a little too conservative? I alternate
between the brakes and the retarder in the mountains and so far have been
able to get down slowly without ever getting my tranny temp much over 200.
Of course it helps to read the Mountain Guide and choose the lesser hills.
My recent trip back from Oshkosh BB Rally saw lots of long hills and both
the brakes and the retarder got good workouts.

On 22/08/07, sfedeli3 <sfedeli3@...> wrote:
>
> Hi Art,
>
> The tranny will heat up pretty quick- 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.
> The thin sheen of oil is probably the result of a leaking hydraulic
> fan hose or tranny hose somewhere. Check all of the big 1-1/2" hoses
> going to the tranny and hydraulic fan motor. If you've never replaced
> them, it may be about that time. I drove 200 miles a few years ago and
> arrived to find my toad covered in oil from the hydraulic fan sump. As
> is turned out, the supply line from the sump to the fan motor had
> rubbed against a hose fitting and ruptured. Thank goodness for dawn
> dish detergent. What a mess! The tranny cooling lines are under VERY
> high pressure when you engage the tranny retarder. I'd have them
> checked out ASAP or just replaced if you don't know how old they are.
>
> Shane Fedeli
> 85PT40
> Hershey, PA
>
> --- In WanderlodgeForum@yahoogroups.com,
> "amweath"
> wrote:
> >
> > Got back Monday eve. from the Montery Historic Auto Races. The Bluebird
> > performed almost flawlessly. I do have two concerns.
> >
> > When coming down the grade into San Luis Obispo, I had the first occa-
> > sion to use the retarder. The grade is steep but short (2nd gear going
> > up). What was alarming was how fast the trans temp went up - maybe 25
> > degrees in 15 seconds of use. Is this normal? It does hold well though.
> >
> > The other item was a light sheen of oil on the back of the coach when I
> > got home. I traveled about 800 miles. I can't imagine it coming from
> > the exaust - not a hint of smoking.
> >
> > The races were quite an expirience. They featured the Indy Roadsters
> > from the mid-50s to the mid-60s among, of course, many other types.
> >
> > Any insight into the two concerns is appreciated.
> >
> > Art Weatherly
> > Riverside Ca
> > '85 PT36
> >
>
>
>



--
Rob, Sue & Merlin Robinson
94 WLWB


[Non-text portions of this message have been removed]

[davidkerryedwards]

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
>
>

[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
> >
> >
>

[Don Bradner]

The difficulty is in determining the effect of short-term retarder temps
compared to elevated "operating" temps.

Allison says "Normal range 160-200, Maximum 330 Intermittent"

The 330 number for my HT755 is found here:
http://www.allisontransmission.com/servl...bs&Fi\
leToGet=OM1475EN.pdf and I imagine I can find a similar listing for other
Allsons (give me a model number).

On 8/23/2007 at 3:19 AM davidkerryedwards wrote:

>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
>> >
>> >
>>
>
>
>
>
>
>Yahoo! Groups Links
>
>
>

[sfedeli3]

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"
wrote:
>
> 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
> > >
> > >
> >
>