[ImperialCrown]

Also inspect the inner axle stub shaft seal surface finish where it contacts the seal rubber. If it is worn, grooved or dinged, the seal will probably leak ATF again.

 

[MoldyOldy]

I know it's not a fair question to ask, because every shop & city has different labor rates, but what would a very rough ballpark be for something like this, assuming that's even the problem.....It sounds like one of those jobs where you're into it for 1200 in labor to replace a $30 part........If we're looking at over 2 grand, the yard may be calling....

 

[John Wood]

I'd guess a grand. That includes pulling the tranny. Parts are probably $25 to $40 but most places mark them up a bit. That would include 2 bearings, 2 seals, and RTV for the housings and cover. Expect another couple hundred for clutches and seals which is a good idea on an old tranny (i.e. basically a rebuild).

I'd be be nice to confirm a possible bearing failure, but the growl could provide a good clue. To positively confirm by yourself, you need to pull the axle and the extension housing on one or both sides. The bearings are a common tapered variety and you would be looking for grooves and pitting in the cone (which is in the extension housings). If you opt to take the driver's side off, mark the top of the housing. It can just be squeezed in one way. RTV is used to seal it back to the tranny case.

 

[ImperialCrown]

In order to get an accurate carrier bearing preload adjustment, the transfer gears and shaft must be removed so you are only measuring only the carrier bearing drag itself. This can't be done easily or accurately with the unit installed in the vehicle and it should be on the bench for this operation. This is the procedure given in the service manual and that would be the shop method.
Shop flat rate times vary by shop. A few calls in your area should yield some numbers.
First confirm that the bearings are really your actual problem or continue on with your noise diagnosis.
If this is truly a 1990 A-604, many improvements have been made since then and a reman would likely be recommended over rebuilding what you have. The latest TCM software is also the best way to go. Evaluate the vehicle's overall condition before deciding on an expensive repair.

 

[SDP]

I also had an intermittant, high pitched LOUD squeal/whine in my 95 Sebring coupe that I would have sworn was in the left front. It drove me crazy! After jacking up both sides and looking for slop, it appeared that it was possibly a bearing, although the noise did not really support that conclusion. Being intermittant made getting a diagnosis difficult but my shop correctly found that the noise was from 'dry' rear brake pads...they lubed both sides and the noise went away. I hope that you discover that your problem is equally as "unlikely" and inexpensive to repair!