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mleras · 08-22-2009, 02:26 AM

I have a mechanic giving me total grief in repairing my motorhome transmission. Does anyone know what flexplate to use with the diesel motor?
Airstream factory says use a turbo 350 flexplate but the bolt holes do not line up. He is also charging me an additional $500 to install a new torque converter and pilot bearing. He said they are warn and scored and It will leak. Originally he charged me $500 to fix the noise in the tranny. He tightened torque converter bolts and fixed a couple of leaks. The noise was still there. I took it back and he discovered a crack in the flexplate. He quoted me $800 to repair it at a discount because of not finding the problem the first time. I found an other shop that would do the job for $500 he matched it. Now he is heisting me for additional $500 to do the torque converter. Any ideas?

Mike Leary · 08-22-2009, 07:48 AM

I had my trans rebuilt not long ago, I'll check the paperwork when I get back from work.
Off the top of my head, I thought the trans was a 370 turbo. Some Allison parts fit that unit, including a torque converter. I'm not too happy they way the trans mechanics are jerking you around.

overlander63 · 08-22-2009, 08:05 AM

Welcome to the forums.
A couple of questions:
1: Does the transmission leak now?
2: Does the motor home move under its own power now?

Without seeing pictures, it's hard to tell, but it's possible the current mechanic may be trying to find something else wrong to make up for the discount he gave you. If the motor home will drive, take it to the shop that quoted you the lower price, and let them look at it. Try not to tell them about the grooves (all torque converters get them to some extent), and see what they say.
If it doesn't leak, drive it the way it is until you start noticing fluid leaking from there, then get it fixed. At least you will know what it is, and about how much to fix it.

BTW, I've never seen a pilot bearing on an automatic transmission, they are pretty much exclusively a manual transmission part. The pilot bearing goes in the end of the crankshaft, and supports the input shaft of the manual transmission when the clutch is released.

LJH · 08-22-2009, 09:07 AM

Pilot bearing? You don't need no stinkin pilot bearing! Terry is correct, they are for the input shaft of maual transmissions. LJH

nate3172 · 08-22-2009, 09:45 AM

Mechanic here that has done more than my share of transmissions. This guy sounds like he is running you through the ringer. There is no pilot bearing with an automatic only standards use them. So he didn't happen to see the crack in the flexplate the first time you brought it to him, but what reasoning does he have to replace the torque converter? If the trans is working but just has a noise than what makes him think the torque converter should be replaced. Usually, in the repair field, torque converters are replaced when the transmission is rebuilt or replaced or if there is a specific problem with the torque converter. Even then, if the converter has a problem internally, it usually sends debris throughout the rest of the trans and it would need to be pulled apart and gone through anyway. Sounds like he is not sure what is making the noise and is looking to narrow the possibilities by just convincing you to replace parts that you might not possibly need before he even starts the job. Also, not sure why he would charge an EXTRA 500 if he already has the transmission out for the flexplate, it only takes an extra five minutes to put the torque converter into the front of the trans. I cant imagine the converter itself costing that much and its really no extra labor since he would already have it pulled down that far for the flexplate.

Mike Leary · 08-22-2009, 12:06 PM

I'm thinking both mechanics are full of it, including AS. This your transmission.
Mine was rebuilt in 03, it has 125K on it and works perfect: built by a old timer
who really knew his gearboxes.

RBolton · 08-22-2009, 02:15 PM

Did the first mechanic have the transmission out of the MH for the first round of repairs? It would not have been necessary if he only tightened torque converter bolts - unless one of the orginal leaks was at the front pump. How does he know that the convertor hub is scored? It would seem that he either had it out once and didn't mention it. Or he is guessing now. Or he has the transmission out now. Does he?

By pilot bearing he may be meaning the front pump bushing.

Mike Leary · 08-22-2009, 02:35 PM

Those are great transmissions, twice the size as Ford. I'd sure bail (if you can) and find a gearhead that has extensive experience with Chev/GMC/Allison transmissions. Watch how the cooler lines get back and forth; I had one rub a hole and just happened to notice the leak. If it makes you feel better, I spent lotsa $$$ before I found someone to get the airbags squared away.

swanky · 08-22-2009, 03:06 PM

Hi: I am not sure if this will be helpful, but my flywheel and torque converter were replaced by Custom Transmission in St. Mary's, Ohio. I think the guy's name was Steve? I can't find his number.
He charged me $215 for the torque converter and $60 for the flywheel (parts). The labor to remove the transmission assembly and reinstall it was $495.00. He might be able to tell you what you need and what is a fair price. The total for everything, including trans fluid and engine mount was $866.00. The price before he discovered the broken torque converter was $600. Hope this helps.

Mike Leary · 08-22-2009, 03:18 PM

I guess it's how many miles you want to get out of that hard-working transmission.
Our re-do was around eighteen hundred $, parts & labor. I'm pleased to have paid it.
If the trans guy knows about Allison, you're home.

Smartstream · 08-22-2009, 05:25 PM

If you have the TH400 trans you should use the TH400 flex plate. There is no pilot bearing however there is an adapter that connects the flex plate to the crankshaft. There is an adapter plate/ring that connects the Isuzu to the GM transmission. It is about 3/4" thick. This is the reason for the adapter that moves the flex plate 3/4" back from the crankshaft to reach the torque converter. The spud on the front of the torque converter fits in a recess/register in this adapter for support and location (alignment). If your torque converter comes loose and rattles around a bit it can damage the fit of the torque converter to this adapter. This can cause the torque converter to not run true and damage the input bearing/front pump. If one of the leaks he originally repaired was the front pump he would have had the trans out to replace the o-ring seal.

When my flex plate broke it damaged the crankshaft to flex plate adapter and broke the alignment spud off the front of the torque converter. The torque converter had to be replaced and the adapter had to be welded up and re-machined as there are no replacements available.

Cheers, Dan

overlander63 · 08-22-2009, 06:20 PM

The person that started this thread hasn't been online since they made the post. Maybe we should wait for them to check back in before speculating further.

Mike Leary · 08-22-2009, 06:40 PM

Quote:

Originally Posted by overlander63

The person that started this thread hasn't been online since they made the post. Maybe we should wait for them to check back in before speculating further.

Why? Good information is being exchanged for everyone's use. Do you have a mo/ho?

overlander63 · 08-22-2009, 07:17 PM

Quote:

Originally Posted by Mike Leary

Why? Good information is being exchanged for everyone's use.

Because speculating without sufficient info is pointless. Do we know if they have a Turbo Hydramatic transmission? Is it an Allison? Has anything been altered "under the hood?" We have someone in this thread thinking it may be one, and another thinking it may be the other. The original poster doesn't say.
What we have so far is someone saying "tech A says this, and tech B says that. Which one is right?" We need more info.

Mike Leary · 08-22-2009, 07:41 PM

No way it could have been a Allison, but some parts interchange into the 475; that's what makes a hot rod trannie.
What does "no longer at Inland RV" mean, is that some kind of in-joke? I don't get it.

RBolton · 08-22-2009, 08:41 PM

Quote:

Originally Posted by Mike Leary

What does "no longer at Inland RV" mean, is that some kind of in-joke? I don't get it.

Did I miss something?

Mike Leary · 08-22-2009, 09:01 PM

Quote:

Originally Posted by RBolton

Did I miss something?

I must have; seemed like Terry had found a home.

mleras · 08-23-2009, 09:48 AM

Thank you everyone for your input. The original $500 covered tightening the torque converter bolts. He said they were hard to reach and they were a little loose. That part was $200. Then he charged me an additional $300 to straighten out the pan, cut out part of the cross member that was rubbing the pan and fix a couple of leaks near the bottom of the pan. At that time he never removed the transmission. I picked up my motorhome only to hear the sound still there. I think as it warm up it gets louder. I promise my family a short drive to the beach and returned the motorhome to the mechanic. He thought it was in the engine. I said disconnect the transmission so we know for sure. After having several mechanics including a diesel mechanic (which said the engine sounds tight) he discovers a hard to see crack in the flexplate. Which was my original assumption. He told me it would take eight hours to fix but because he did not find it the first time and due to my getting mad over the money spent for nothing. He said he would knock of the $200 spent the first time on the bolts. So the new quote was $700 and I supply the flexplate to save me money. I thought this was high so I called another shop. They said it was a six hour job and gave me a discount of $500 and I supply the flexplate. I told the old shop about this quote and they finally agreed to do it for $500. I should of ran with my motorhome at that point. My wife was right. He told me he would have to charge me $100 for his time if I went to another shop. So out of convenience I let him do the work
Now the transmission is out of the motorhome and he can not find a flexplate that fits properly. Airstream said put in a standard GM turbo 350 flexplate it does not have weights. The mechanic says the holes are in the wrong place and will need to be drilled like the one that is cracked in the motorhome. Upon removing the transmission he discovered that the torque converter has some grooves and some bearing (I can remember which) will need to be replaced or it will leak at the front of the transmission where it is coupled to the engine. He wants and additional $500 to do that work which includes the parts. I am so mad. Originally I told the guy times are tough for me right now and I just want to get my motorhome repaired so I could sell it. He keeps telling me he will work with me. I think he is working me. On Monday I will go to the shop and see the torque converter and parts. Help!
Thank you,
Mike

overlander63 · 08-23-2009, 09:55 AM

Quote:

Originally Posted by Mike Leary

What does "no longer at Inland RV" mean, is that some kind of in-joke? I don't get it.

Quote:

Originally Posted by RBolton

Did I miss something?

Quote:

Originally Posted by Mike Leary

I must have; seemed like Terry had found a home.

I no longer work there. It didn't work out.

overlander63 · 08-23-2009, 09:58 AM

Quote:

Originally Posted by mleras

Airstream said put in a standard GM turbo 350 flexplate it does not have weights. The mechanic says the holes are in the wrong place and will need to be drilled like the one that is cracked in the motorhome.

It's been a while since I've had one out, but I think the Turbo 400 has a slightly different flywheel/flexplate. You may find one that is pre-drilled with both sets of holes, I'm assuming the holes that are in the wrong place are for the torque converter, not the crankshaft.

Here's a link to a non-weighted turbo 400 flexplate, it says it's about $20:
http://www.rockauto.com/catalog/rafr...c1297177k65712