Problems with transmission - torque converter

[SoCalSlaughter]

Hey everyone, have a problem and was wondering if anyone had any ideas. I recently had my TH400 trans rebuild by a local trans shop. New case, torque converter everything. Installed it myself (to save myself $400) took it back to the shop after installed. They said everything look perfect. Truck drove awesome for about 1000 miles. Then after a start up the truck was having a vibration. Can feel it in steering wheel and side view mirrors shake. Does this in idle and in drive. And with a rev up to about 3K rpm the shutters super bad. I cant go over 65mph without it shuttering. Also shifting, at the top of the rpm band just before shift it shutters. So got under the truck, took the bottom converter cover off to look for loose bolts or flexplate cracks. Couldnt find anything. So unbolted converter from flex plate and found the converter is super loose, it can move up and down, side to side. tons of free play. Im thinking the converter bearings are shot. Any other ideas? Or why this could happen on a brand new rebuild?

- 1990 V2500 4X4 Suburban - TH400 - 5.7 350 TBI

[ChevLoRay]

What does your transmission guy say?

Unless the bolt holes for the torque convertor are enlarged, I can't think of a good reason for it to move. Okay, whatever takes the place of the pilot bushing on a stick....is that the bearing you asked about? I don't have any experience with torque convertors like these so I'm not the guy with the answer.

The reason I mentioned the bolt hole thing is from personal experience. I had a '56 Merc and it had a slight metallic rattle. It was diagnosed as a bad flex plate. That is a flywheel in today's jargon. Anyway, it had three tabs that were riveted to the it and that is what the torque convertor was attached to. They had the tiniest bit of movement....maybe a millimeter, but that was enough play to create one heckuva clank at idle. It didn't affect anything else, but it was embarassing for a 19-yr old boy...and in the company of new '66 GTO's.....at stop lights. So, to compensate, I'd hold the brake down, and give it a little gas. That was called "jackin' it up". Yep, usually meant that you wanted to race. That old Merc was no slouch on the bottom and I had a lot of fun.

What you might do is what I did....hold the brake and give it some gas to see if the noise gets worse or quits. It won't fix anything, but you'll have some more ammo.

Good luck.

[SoCalSlaughter]

Someone had told me there are bearing in the converter that can fail. When i first put the converter on the trans, it fit firmly and the truck drove fine. Now when I unbolt the flex plate the converter has a ton of play. Thats why I think the converter had taken a carp. Im not sure if its a reman converter or a new one. I havent been to the trans shop yet to ask, been trying to find the problem myself. Today I unbolted the converter and turned it so the to the next set of bolt holes and put it all back together and for the most part the vibration is gone. But the fact that it has so much play and feels loose on the input shaft of the transmission worries me to drive it.

[71monteme]

there is def. something wrong with that rebuilt. when you put the converter on the input shaft, after the 3rd click- seating the converter on the input shaft, there should no play at all. there should also be no vibration at all. i would bring it back to the shop before it breaks and need a new rebuilt.

thanh