replacing carrier bearing....

[ARCHINSTL]

Seth -
When Petros mentioned that the mount has to be loose to accomodate the movement of the rear shaft, he meant that the rubber surrounding the bearing in the mount has to be flexible for the accomodation. The mount itself does not move on its attachment to the belly pan.
Don't take the preceding the wrong way - it just seemed that you were unfamiliar with its operation.

And what 4wdchico mentioned about the U-joints eventually affecting the seal and/or bushing is true - as I discovered. Hopefully my bushing is not toast, as I wade into it this weekend - but I have one if needed.
Tom M.

[SethM]

OK, thanks all. I have been out of commission due to some foot surgery and can't crawl under the car to take a look at what is going on. And then the issue of whether the RI inspection (at least at this garage--- a state licensed inspection station) is to be believed is an entirely different issue. What exactly would the symptoms of a bad/worn carrier bearing be?

[Petros]

There would be lots of bearing noise when the car is moving, even louder when in 4wd and power is being driven through it. It will be either a whine, or a noticeable bearing roar (bad). It tends to echo through the car pretty good since it is right at the center of the floor pan. You can hand check if it makes no noise, if when you crawl under the car (trans in neutral, one rear wheel off the ground) and you turn the drive shaft you can feel if the bearing runs smooth, it is good. Usually if there is any roughness in the bearing, it will degrade soon enough to be so noisy you know something needs to be replaced. So simply listening for bearing notices (whine or grinding roar) is usually all that is necessary.

If you have to you can unbolt the center carrier and drop the drive shaft without removing it. Than you can freely turn the center rubber mounts, and can feel directly the condition of the bearing. You do not have to remove the front or back ends of the drive shaft, just the center mount and pull it straight down.

If it is good, you can either go argue with incompetents or liars at the state approved shop, or find another shop to okay the bearing, and file a complaint against the last one, and demand your money back.

I still can not see how this bearing is even a state issue, you might be getting swindled by an unscrupulous shop, even if it needs a bearing. Just find it difficult to believe that this is on the checklist of items to pass inspection. Is MA at such a level of police state that they have detailed check lists for every model of car driven in their state? I should hope not.

I would call the state inspection agency and ask a number of pointed questions about validity of requiring a drive shaft bearing needing replacement. On the old u-joint drive shafts if they got bad enough they could fail and leave a car stranded, but that means it was really bad. The owner usually will not drive it because it feels really bad, and makes lots of noise. I suppose it is possible there was a safety related law after a bad accident was caused by a failed driveshaft, but that really seems a stretch.

[ARCHINSTL]

Audible symptoms are a vibration amidships - although with our cars, a lot is telegraphed (they are little buzz boxes). I'd guess that the tech had it up on the rack and noticed that the shaft moved around inside the support; short of metal chunks falling from the bearing, I think it impossible to determine if the bearing itself is shot, as the shaft is a press fit into the bearing itself.

I forgot to add to tools needed - a 12mm crowfoot wrench to adapt the torque wrench to the nuts (there is too little room to squeeze in without one).
I (partially) drained the oil from the back hole - about 2+ quarts. Again, be sure that the filler plugs can be loosened first. You do have to remove the front shaft - remove the rear first for ease in handling.

Various threads on replacing the carrier (do a Search) seem to indicate that the bearing itself rarely wears out, but the rubber surround perishes and allows the bearing to move around. That is the case with the one I just removed; there was about 3/16" complete freedom of movement inside the rubber, which was also as hard as a rock.
Tom M.

[takza]

"Notchy" u-joints are probably like the universal on the steering shaft...a good soak in light oil would likely free them up. DRY?

I had one go out in the desert in deep sand...needle bearing disintegrated from the extra load...bought a new one and was able to replace it on the road...or off of it to be more precise.

EP grease is the only lube that will work in a driveline u-joint. Stock u-joints cannot be greased or replaced. Notchy = failing. The stock 'yota u-joints, once they get notchy, can go a long time before fully failing. Plenty long enough to wipe out the TSH bushing and seal.

Notchy but not loose probably = DRY. The light oil gets in past the seals and reliquifies the old grease...prolonging the life of the universal.

[SethM]

OK, thanks all--- I have been out of town for an extended period and only today started to address this again. Figured I would start with a different shop (licensed to do the RI state inspections), BUT ran into a sudden problem which I'll post in a new/separate post.

[takza]

I've been oiling the universals on the driveshaft...thinking that if they get stiff after a lot of miles...oiling them might stop some of the driveline rumble...doubting if the source is the rubber around the carrier bearing.

[SynthDesign]

FYI, Harbor freight sells a $4 tool that fits into the rear housing to seal the trans when the drive shaft is removed. Previously I have used a cap to a flite sized shaving cream bottle that worked in a pinch and quite well.

When I had a carrier bearing fail, it stalled the car. This was was after 10 miles plus of high pitch screeching. Drive shaft removed and baggy ziptied around the end of the trans we made it home just fine.

IMO, if the rubber is gone for the bearing support, replace it. I just stock up on good driveshafts from the pull-a-part.

[Petros]

I just stock up on good driveshafts from the pull-a-part.

which one did you go to? How many are there?

[SynthDesign]

@ Petros

I've stocked up over the last three or four years. I think I have 4 good workin ones as spares.

Not a single Tercel at pull a part recently in Lynnwood