Tanny Problem?

[4G63t Power]

Ok... Im lost... Whenever I open it up to full and spool up I get a strong vibration in the floorboards. when I bought the car the guy said it was that the carrier bearing bolts were lose and I just needed to tighten them. I did that and it still does this. When driving normaly... the vibration is very very slight, If you werent looking for it, you wouldnt notice it. Again it only vibrates hard when I am accelerating hard and spooling up. It feels like it is coming from the second carrier bearing (closest to the back). The vibration feels like its right behind the center console. I already checked and there is nothing rubbing or in the way of the driveshafts rotating. The carrier bearings themselves do not seem worn out and there is not alot of play in them and there is no clanging when I pull on the driveshaft. The tranny was just recently rebuilt and he put in back on. This has gotten really annoying and I cant figure out what it is. Any insight would be great. Please Help!

[4G63t Power]

By the way... It is AWD...

[kjewer1]

Hmm. I have no idea. I would expect carrier bearings as well. Could be the rearend perhaps, but those fail so rarely its ridiculous, even considering that 99.9% of DSMers take these cars to 150-200k miles and never change that fluid But its worth checking. Not sure how you could tell its bad though. Mine is still "good" and there is a ton of backlash in it Not sure what a bad one would look like. The only thing in the tranny that could be hosed and still allow you to drive the car is the center diff. Might be worth opening it up and putting an eyeball on it. If the pieces from that get out you will lose other shafts/gears. But typically a broken CD will lock up when making tight turns, and you dont mention that.

I'm stumped, you'll just have to start ruling things out and see whats left.

Just had a thought, drain the tcase fluid. I was getting more of a grinding than a vibration when mine was letting go, but eventually it will lock up and has it has killed people. MAke sure the fluid isnt a silver soup, and check the grain plug, it should be magnetic. Thats an easy 15 minute job that will rule out one more suspect.

[EclipseRST]

Are you sure its in the driveline? I have seen a good amount of vibration in the floor of the car when the rear balance shaft is 180 degrees off. Doesnt really do it that bad until 3000+ rpms. Might be something to check into before you go tearing your whole drivetrain out... Just my $.02

[kjewer1]

It would be unlikely for it to have moved though. It should also vibrate based on RPM, not load. But it isnt' uncommon for the front bashaft belt to break, which can be similar to have the rear out of phase (since there is no front shaft working with it). It could be a number of things... Who knows what it will end up being.

[EclipseRST]

Well he said it was happening when he got it the owner just told him the carrier bolts needed to be tightened... So if the owner did a timing belt job wrong that could be a cause. I'm just throwing out options he has to check so he can go check everything and if its still not that then we can start looking to other things, process of elimination

[4G63t Power]

Thanks for the input guys... Ill check out what you said... But it is deff coming from the floor... and its deffinatley a vibration to and not a grind. Is there anyway to check to see if the carrier bearings are worn out... I was told to pull on the drive shaft and if it clangs or has alot of play that there shot, but it has neither. The vibrate is also only under load... not RPM. If I slowly take it up to redline... its fine. If I punch it... then I get the vibration. Even at high speeds, say 85, it doesnt do it unless I try to accelerate hard. Im lost... Ive looked over the whole tranny a million times and cannot figure it out. Ill check in to what you guys said tomarow morning and let you know if I find anything new. Thanks.