QuestionTed, I have a 1999 Toyota Corolla / manual transmission, purchased new, w/ just over 100K miles.
During the last 10K miles I have replaced a driver's side wheel bearing (it was making noise, free-play at the wheel when I checked it).
No problems for the next 10K miles after the wheel bearing replacement.
My wife reported a new noise to me; upon investigation I determined it was coming from the driver's side again, this time (apparently) from the CV joint / axle.
I purchased a rebuilt CV / axle until at my local auto parts store, and installed.
Upon test drive, exact same noise (cyclic "thumping", almost like you would have w/ a bad / out-of-round tire).
I put the car back on jack stands, and while in gear, it's clear that the noise is coming from the driver's side output shaft area.. You can see the transmission side of the CV joint bouncing up and down, w/ much greater play than usual. (I also own a 2000 Corolla since new as well, and there is a lot of play on that one too, but it's not defective (yet!).
I called the dealership and they claim that a failure of the output shaft bearing is not common, but I really don't see what else it can be. It has to be in that general area..
I've downloaded the documents from T.I.S., and I have a Haynes manual as well. It looks like to get to the transfer case portion of the transmission it has to be completely disassembled, and I don't have some of the specialized tools necessary, nor do I have the time. I'm fully competent and capable of R&R'ing the transmission in my driveway (it's due for a clutch as well), but I'd like you input on this / have you seen this failure before?
Frankly, I don't see how this assembly lives as long as it does; the driver's side axle is too short in my opinion, and there seems to be too much play in the diff bearing, even on a "good" one. The driver's side output shaft seal has been replaced twice now, once by the dealer under warranty at about 20K miles, then by me at about 70K (still sealing o.k.). With so much play I'm surprised they seal at all.
So I found a shop who will do bench work for $150.00 labor, plus whatever part(s) it needs. They also mentioned that if it's what I think it is, that the case might be damaged / unsalvageable as well. I sure hope not.
I've been advised to just buy a used transmission, but I know the history of this unit, the syncros are fine; I wouldn't want end up doing all of this work and have it fail for a different reason down the road.
So what do you think? Seen / heard of this before? Am I on the right track? What are the consequences of allowing her to drive it in-town until it's repaired? Thanks again, Ted.
AnswerIt sounds like there is a problem with the differential unit in which case it is best to replace the entire transmission assembly, when the side bearings fail it almost always damages the transmission case.
Check the fluid, remove the drain plug and see if there are metal particles in the fluid, the differential and the transmission are not isolated from each other and both use the same fluid.
