Post Reply 
 
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Shock mount: Re: Temps
06-18-2008, 20:36
Post: #4
Shock mount: Re: Temps
The stress crack/tear in the metal was over 7" long, so the problem must have been developing for some time. (The popping noise had been with me for some time, too.)
I don't know if the raising/lowering the coach was the last straw, or what ... (might have been) But airing the coach before raising the jacks is tough (on my coach) since the air bags are dumped automatically when you lower the jacks, so I don't know if they'll refill until the jacks are raised. (Does someone know precisely how that is set up?) I know I've forgotten to dump the suspension before I started the jacks ... but then they dump anyway.
Pete Masterson
'95 Blue Bird Wanderlodge WBDA 42
El Sobrante CA
"aeonix1@mac.com"


On Jun 18, 2008, at 10:43 PM, David Brady wrote:

It must feel better to get that off your chest. See what wonderful
therapy this list is, and free of charge! I remember when you
described the work that Henderson's did some months ago. I recall
that you had BB in the loop and they suggested "hammering it
back in place and welding it". I've had welding work done in the
past by shipyard welders and have been impressed. These guys
work with heavy equipment routinely and pay attention to stress
flows, risers, mitigation, etc. Some people can look at a steel joint
or interface and picture in their minds exactly how the lines of stress
radiate and how to spread the load with gussets. I wonder if you
had shock failure in the CCW parking lot due to them raising the
front of the bus with the HWH jacks, and then dropping it w/o
first getting some air in the suspension. If so, this may have been
the last straw for the mount. We know by now that there's not
a lot of tolerance between the suspension bottoming on the air
bag bump stops versus the shock bottoming internally exerting
"shock" loads into the shock mounts. Ever wonder why you only
have this problem on one side of the coach? The reason is that
the other shock mount shares it's upper bracket with the panhard
rod, which is an extremely stout structure, as opposed to the
driver's side upper mount which is a wimpy flange and bolt
huck bolted to the vertical flange of the c-channel frame. So everyone:

1) keep an eye on your drivers side upper shock mount,
2) check your shocks to make sure they're not too long in the fully
compressed state which leads to the shocks bearing the load of the
coach instead of the front airbag bump stops, and
3) air up your coach before you retract your HWH landing gear.

David Brady
'02 LXi, NC

Pete Masterson wrote:

The long story: Same shock mount....

Henderson's noticed a crack along one edge of a 'rib' on the left front shock mount. They welded it ... but in reviewing the ultimate much more serious failure, they (Henderson's) didn't know much about proper welding technique. (I'm no expert either ... but after seeing what CCW did vs. what Henderson's did, it is obvious that the Henderson's welder may have had a high-school welding class and was not a certified welder.)
I had been noticing a 'popping' noise in the front end -- to my ear, it sounded like it was coming from the curb side of the coach ... but that may have been misleading. The popping noise occurred on heavy dips and on wavy bits of road (as are common on the freeways in the SF Bay Area that were built on fill land). I now realize that it was probably the mount tearing itself apart.
The requested inspection found a loose 'fender' (a piece of metal up in the curb side wheel well) that was screwed back in place (OEM was a single screw, which broke. Now there are two screws). That was thought to be the source of the noise. (We hadn't road tested the coach.) Some other work was done and we were about finished with the list when we made a small move (a few feet) and suddenly the left front air line was separated. Upon inspection, it was found that the shock had completely torn away and took out the brake line when it came loose. The shock mount was severely torn and bent.
One of the technicians assigned to my coach had actually worked for several years as a certified welder in a shipyard -- and he was supervised (on this job) by yet another certified welder. The prep work they did was significant and impressive compared to the bend it back and tack it weld done at Henderson's. The weld was also given additional gussets to strengthen the area of the crack -- and all the area was completely ground down and all rust was stripped away. (I don't recall seeing that Henderson's did any of the prep work like that.) I note, too, that CCW had the heavy shop equipment necessary to straighten out the bends in the torn off piece -- they must have a heavy press somewhere on their facility as the bent up 1/4" piece of steel that was torn off ended up beautifully flat before it was put back in place.
CCW was very careful about the electronics and took everything offline, removing the battery cables, isolating the DDEC unit by removing the wires from it on the engine and similarly isolating the electronics for the transmission. (I don't recall Henderson's doing any of that, either.) Then there was a _lot_ of welding -- with an assistant standing by with a fire extinguisher. All in all, the CCW team did a very professional job of welding and strengthening the shock mount. Unfortunately, the shock itself had been bent at one end during the failure ... and I discovered that Koni shocks for BB buses are not on every auto parts store shelf. As luck would have it, the shock ordered overnight from Hayward (No. CA) was lost by UPS! To avoid keeping me over another weekend, they arranged to remove an identical shock from another coach (which had recently had new shocks installed) and got me on the road. (The shock ordered for my coach went on the other coach when it eventually arrived.) However, this little incident added 2 days to my stay.
Since the shock mount had reached imminent failure enroute to CCW, I actually feel lucky that it happened to let go while located in the service area at CCW as compared to any other possibility. (I'm a little surprised that it wasn't seen until the failure occurred -- but I guess they just missed it.)
I guess the lesson here is, if you have a 95-97 PT-42, be sure to take a look at your front shock mounts carefully. BB apparently used a variety of designs (from what I hear) and it's probably because they've had some troubles with that component in the past.
Oh, yeah. The popping noise is gone.
Pete Masterson
'95 Blue Bird Wanderlodge WBDA 42
El Sobrante CA
"aeonix1@mac.com"


On Jun 18, 2008, at 9:37 PM, David Brady wrote:

Ouch, another failed front shock mount??? Is this the one that Hendrickson's
welded for you? I guess you are stuck with Windows if you want VMSpc,
or for mega-bucks you can buy one of their stand-alone units, or you could
pioneer a linux/wine installation. Ten days w/o a toad, I feel your pain.

David Brady
'02 LXi, NC

Pete Masterson wrote:

After the trouble CCW had getting the interface to talk with their computer, I'm sure I won't be getting VMSpc. (Besides, I'm an all-Mac kind of guy and I really don't want to get a Windows computer.)

CCW eventually had to dig out an old Windows 98 laptop to hook up to my connector. They just couldn't get anything newer to talk to the old hardware. At least they had one around to use ... and, of course this added another day to my sojourn there.
Hint: Take a toad with you if you ever plan to stay with your coach at CCW in Riverside! I opted not to, and I regretted it (I was there for 10 days -- I'd planned on 3. The long stay was not all their fault as there were some problems getting parts quickly and a last minute discovery of a failed front shock mount didn't help).
Pete Masterson
'95 Blue Bird Wanderlodge WBDA 42
El Sobrante CA
"aeonix1@mac.com"


On Jun 18, 2008, at 8:54 PM, David Brady wrote:

Series 60. I thought maybe you were getting your temps from
VMSpc, or the like. I know my dash gauge reads 6 deg F high.

David Brady
'02 LXi, NC, (I bought the engine, the bus came with it)

Pete Masterson wrote:

Does the 02 have the DD Series 60 or did they move to the Cummins?

Of course, it's possible that my thermostat is 5 degrees off, or so -- or my interpretation is off, since there's no mark at 190 or 195 -- as I recall, the mark is at 180 and 200...
The radiator guy told me what the thermostats were (OEM standard by the engine owners manual) but I don't recall exactly what they are.
Pete Masterson
'95 Blue Bird Wanderlodge WBDA 42
El Sobrante CA
"aeonix1@mac.com"


On Jun 18, 2008, at 8:22 PM, David Brady wrote:

Pete, what thermostat are you running. My coach likes to run at
195 deg F. It could be that the newer coaches run with a hotter
thermostat.

David Brady
'02 LXi, NC

Pete Masterson wrote:
Water temp hasn't been over 190 or so ever since. On that first trip, I spent half the time staring at the water temp gauge as it 'hung' at around 205 or so... 

No virus found in this incoming message.
Checked by AVG. Version: 7.5.524 / Virus Database: 270.4.0/1506 - Release Date: 6/17/2008 4:30 PM

No virus found in this incoming message.
Checked by AVG. Version: 7.5.524 / Virus Database: 270.4.0/1506 - Release Date: 6/17/2008 4:30 PM

No virus found in this incoming message.
Checked by AVG. Version: 7.5.524 / Virus Database: 270.4.0/1506 - Release Date: 6/17/2008 4:30 PM
Quote this message in a reply
Post Reply 


Messages In This Thread
Shock mount: Re: Temps - Pete Masterson - 06-18-2008, 16:23
Shock mount: Re: Temps - David Brady - 06-18-2008, 17:43
Shock mount: Re: Temps - David Brady - 06-18-2008, 17:46
Shock mount: Re: Temps - Pete Masterson - 06-18-2008 20:36
Shock mount: Re: Temps - Pete Masterson - 06-18-2008, 20:53
Shock mount: Re: Temps - David Brady - 06-19-2008, 01:39
Shock mount: Re: Temps - David Brady - 06-19-2008, 01:48
Shock mount: Re: Temps - Pete Masterson - 06-19-2008, 03:04
Shock mount: Re: Temps - Pete Masterson - 06-19-2008, 03:13
Shock mount: Re: Temps - bumpersbird - 06-19-2008, 04:12
Shock mount: Re: Temps - Pete Masterson - 06-19-2008, 05:07
Shock mount: Re: Temps - bumpersbird - 06-19-2008, 06:04
Shock mount: Re: Temps - Pete Masterson - 06-19-2008, 06:37
Shock mount: Re: Temps - Ed - 06-19-2008, 09:07
Shock mount: Re: Temps - Pete Masterson - 06-19-2008, 12:22



User(s) browsing this thread: 1 Guest(s)