Visit our Popular Forums

Mike Leary · 08-23-2009, 11:00 AM

Good luck, we've all been there. Let us know what happens.

mleras · 08-24-2009, 11:08 AM

The transmission is out of the motorhome so it will not move. There was no leak to speak of before he started his work. I am going to the shop to see what the parts look like. I am in agreement with most of the people who have been replying to this post. Perhaps I should let him do the work of replacing the flexplate and if and when it leaks I start fresh with another shop. I am sure I could find another shop who could match his price even if they have to remove the transmission again.
Thank you,
Mike

RBolton · 08-24-2009, 05:34 PM

Mike,

After reading post #18, I'm not sure your mechanic has done anything really wrong or out of the ordinary. If the converter was found to be loose, one would assume that to be the source of the noise. A cracked flex plate can not be 100% diagnosed without a visual and often time this is only possible with the transmission out. His offer to discount the labor by the original repair amount to replace the flex plate was honorable.

The call to replace the converter and bearing/bushing is ultimately yours to make. It is the responsibility of the mechanic to make you aware of their condition now - while they are visable and accessible. He would have had no way of knowing the condition of these parts until after removing the transmission.

It sounds to me like he is doing things in more or less the proper order. Taking the transmission in and out is a big job in almost any vehicle and the cost of labor gets frustrating especially when the first repair attempt does not correct the problem.

If you can get a correct ID on the transmission and engine and chassis build date, I'd think a GM dealer could help find the proper parts.

Good luck, Roger

mleras · 08-24-2009, 07:28 PM

I went to the shop to inspect the parts. The torque converter was lightly scored and it is my belief that it could be polished with some emery cloth and reinstalled with a new pump bearing and seal. He quoted me $100 including the parts to rebuilt the pump and bearing. I told him to do the work. It will be $600 out the door this trip. I did not really want to spend the money on a torque converter. I hope it does not leak. I went to the auto parts store and found a flexplate. He was concerned with the teeth on the flexplate. I had to show him it had a ring gear internally in the motor. Wow .. he did not notice that. So the old flexplate was completely cracked all around the holes that attaches it to the engine. I am gaining confidence that I will be up and running soon. Hope I made the correct call on the torque converter.... it did not look that bad.
thank you,
Mike

jking · 08-31-2009, 05:10 PM

When we had an '82 280 it had flexplate problems - A/S fix was to install a casting that ;looked like a cage around the bottom of the flexplate/t/q junction ... that broke after only a few miles and put a crack in the flexplate. Then we had a local shop remove the flexplate and weld up the crack. They had a bit of a time getting the balance right, but it ended up OK and cost a LOT less than the poor guy is being told.
Jamie

StingrayL82 · 08-31-2009, 08:35 PM

In the future, if you ever need parts, I have this parts list from when I had my 1972 Suburban, which had a TH400. There are a few differences, but the TH475 and TH400 are pretty much the same...the TH475 is stouter, using straight-cut planetary gears vs heli-cut in the TH400. If you google it, there's a good website that will tell you what the differences are. The flexplate used should be a TH400, not TH350, as Airstream suggests. Also, of note, the TH475 is also known as the 3L80HD (1987 model year and newer, the 3L80 was the new name for the TH400 in '86), so you might be able to find out more, using that model name.

klattu · 09-01-2009, 02:04 AM

The weights on the flex plate are for the externaly ballanced 454...putting on one without weights may cause problems.

mleras · 09-01-2009, 10:38 PM

I finally found the proper flexplate. I have no idea of what the mechanics problem was. He even threatened to start charging me storage because he could not find a flexplate. He was concerned with the teeth on the flexplate. He did not notice the started working of an internal ring gear. The motorhome now runs great. Yeah!!!!

Thank you for all your input.

michael