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reggie
May 6th, 2004, 12:26 PM
I'll start at the beginning.

My transmission failed on my 1996 GMC Suburban. Grinding noise and no reverse was kinda a dead giveaway. When I pulled over, I shut the truck off and got out. I heard a hiss.(becomes relevent). Anyway, I had a tire going flat. The valve stem had cracked. So here i am with a failed tranny while I relace the tire.
Maybe the one good thing in this story is I had 16 days left on my extended warranty ans it covered the repair on my transmission.
Now....I pick up my fixed truck from the tranny shop and i drive directly to the tire place to have my flat fixed. They did fix my flat and also balanced all my tires and did a front end alignment. All good? I dunno! Since then I have a nasty vibration most noticable at higher speeds on the highway..65 and above. I have been back to the tire place 4 times. They rebalanced 4 tires and also rotated. This made no difference in the vibration. Next I went back to the tranny shop where they checked "the obvious" and indicated all was fine. Now I'm getting frustrated. A fifth time bcak to the tire shop and I replaced the 2 front tires..michelin atx 10 ply at 170.00 ea. The 2 tires were only a bit prematurely replaced but i need to resolve this problem. This still made no difference in the vibration. Upon returning yet again to the tire shop, I had the managers meeting of the day with them and they also went for a ride with me. They aggred something was definitely wrong and pulled my truck back into the shop. They balanced the tires yet again and check all front end components to be sure. With still no change they indicated they have done everything they could and the problem does not lie with the tires, rims or front end. As I write this my truck is back at the tranny shop with the info that I recieved from the tire place. Their intent is to send out the driveshaft for balancing. Perfectly understandable. However, I have this sickening feeling that the driveshaft is not the problem. I guess my question is...Is it possible for something inside the transmission to be causing this problem. i.e. torque converter unbalanced?...a bearing they did not replace? I just dont know. What the heck wil my next step be to find this cause if the tranny shop sais it is nothing they did?
The kicker here is I never drove the truck enough after the tranny was rebuilt and before the tires were balanced to know if the vibration was from the tranny shop. Although I feel very confident now that it is not in the tires, rims or front end. Am I going to get the shaft? egadz!

Doug
May 6th, 2004, 05:15 PM
Put the truck up on jack stands and drive it standing still at the speed where it vibrates most. Crawl around and you'll find it.

DW

Mike Hippert
May 6th, 2004, 05:18 PM
What speeds does it happen at? Does it happen in more then one gear? Has anyone looked at your motor mounts? Sometimes when one brakes it will cause bad vibs that are hard to find because no one thinks of it.

reggie
May 12th, 2004, 07:45 PM
Update...

Yes...motor mounts and trans mounts are fine. The vibration is sometimes noticeable at slower speeds 30-35 mph. I feel it just a little bit but most noticable to me in the vibration of my side view mirror. The worst is about 68mph and up from there, the faster I go the worse it gets. To me it feels like the whole truck skaking...visors flaapen away, nirrors shakin and teeth chattering although I do feel it and see it in the steering wheel. Very tough to determine what the cause is.
The driveshaft was balanced but did not solve problem. Have not been able to get the truck in the air (jack stands or hyd. lift) to run it at high speed and inspect it. Trans shop said they had 3 techs drive it and they all say it's in the tires! omg I'm thinking now I'm doomed. Anyway, I use my truck for work so I'm just driving it till I have more time....sucks :( at 6am here on the highway, going with the flow of traffic is 75-80mph. I was told by a mechanic that it certainlty can be an out of balance torque converter but the details for diagosis were not there. In mentioning that to that Tranny shop they said it is rare these days to get a converter out of balance but if I went to a particular tire shop and they said it was not in the tires, he would replace the converter...no cost to me. I guess he just wants a second opinion before trying that option.

Doug
May 12th, 2004, 11:27 PM
I went through hell with mine, wound up being a bad balance job on the tires. Changed out driveshafts, all over the place with it. Figured it out when it was lifted and run at 70mph standing still -- it was so obvious, I really wished i had done it first.

DW