th400 problems
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th400 problems i have an 2000 trans am that i swapped a 6 speed out for a turbo 400. I had a shady mechanic that did the swap and needless to say it is royally screwed up!!! I am looking for a good well known shop that i can take my car to and have it fixed the right way. If any one could refer me to somebody in the Maryland or Virgina area I would greatly appreciate it. I am way down by Maryland International Raceway dragstrip in Budds Creek Md but am willing to drive the distance anny where to get my car fixed. Somebody please HELP
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when you drive at cruising speed it has a very very bad vibration in the middle of the car, gets so bad some times it feels like the car is not completly in gear if that makes any sense to you. When im at WOT it seems to shift decent but all in all something is definetly not right. I had a new driveshaft made and rebalanced so I dont think that is the pro blem. I do still have the stock torque arm do you think i need an adjustable? I heard that maybe my pinion angle my not be right or the trans could just not be aligned right but I have no clue. Does this sound like a internal trans problem or some other problem???????????????
when you drive at cruising speed it has a very very bad vibration in the middle of the car, gets so bad some times it feels like the car is not completly in gear if that makes any sense to you. When im at WOT it seems to shift decent but all in all something is definetly not right. I had a new driveshaft made and rebalanced so I dont think that is the pro blem. I do still have the stock torque arm do you think i need an adjustable? I heard that maybe my pinion angle my not be right or the trans could just not be aligned right but I have no clue. Does this sound like a internal trans problem or some other problem???????????????
How does it act if you go out and lay in to it hard? Shifting hard through the gears? Vibrations are difficult to diagnose because you could have a number of things starting up front at the balancer to the crank, flexplate, converter, driveshaft, rims/tires, etc... It doesn't sound to me like your transmission is the problem but it is hard to say. I have a th400 in my Camaro and I have had issues too. But the thing is, the transmissions rarely have any in between sort of failure. They either work or they do not. The only time I had a vibration which had anything to do with the transmission was a th350 that actually was broken on the inside of the case. But it only acted shook the truck in reverse. Eventually lost 3rd gear and reverse. I am on the eastern shore of Maryland and I know some guys over here. If it is the trans, you would have to pull it out and bring it over most likely, unless you want to drive it or trailer it. There are some guys over towards B-more too. Call ATI who is B-more. They can probably give you a good reference or just build you one.
is possible that he didn't make sure to set the transmission mount so the angle was the same as the previous setup which would throw your pinion angle out of wack. this could cause a vibration.
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Get under your car and check the pinion angle. I had the same problem, but with a lot of tweaking and testing, I have the vibration almost gone. The angle possibly changed due to what you used part-wise. What crossmember did you run? M6 w/ spacers, or a sponser th400 LS1 swap crossmember? I used an M6 w/ 1" worth of spacers and a th400 trans mount like the stickies said and the angle deffinately didn't stay the same as it was stock. That is where I would start first. When I had that problem, someone gave me good advise. If you have access to a dyno, run it and get under there and video tape the tranny, driveshaft, and rear end. That way you can go back and slow the footage down and possibly get a good idea of what and where exactly the problem is occuring. One thing I love is when I converted everything to double adjustable stuff and adjustable TQ arm etc. best thing. It takes no time to do pinion angle. When I had to keep tweaking the adjuster a 1/4 turn each time to dial in the angle, I got to the point where I could park the car, put the back on stands, adjust it, and have the car sitting on the ground ready to go in 5 mins w/ hand tools. I would check the angle first since that is easy to do and rule out.
here is a link to a post that I did on a different message board. It is 2 pages of different things that I looked at over the course of a few weeks. Maybe something in there can give you help. It deffinately helped me..
http://www.yellowbullet.com/forum/sh...d.php?t=167059
mark jr.
here is a link to a post that I did on a different message board. It is 2 pages of different things that I looked at over the course of a few weeks. Maybe something in there can give you help. It deffinately helped me..
http://www.yellowbullet.com/forum/sh...d.php?t=167059
mark jr.
Last edited by BlackDuk98; Feb 3, 2010 at 08:47 PM.
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Thanks alot for the info I appreciate it!!! I am going to get an adjustable torque arm and i will find out what kind of crossmember I have and hopefully something good comes out of this headache I have. By the way the link you posted is a very good informative site.....
