Possible Carrier bearing

[stangman11]

Hey guys,
Just wanted to run something by all of you and get a second opinion on my own diagnoisis. Just bought a 2000 GT vert, love the car but I had the top up for the first time the other day with no radio or anything on and heard a whinning noise comming from the rear of the car. Its not a tire noise because it changes with drivetrain acceleration and decerlation, and its def not just resonance of the car noises. From the drivers seat it sounds like the left side carrier bearing but thats only because I have not been able to listen to it from the passenger side while someone else drives. Could this possibly be a output shaft bearing noise in the trans or maybe the pinion bearing in the diff? Has anyone else had the same problem ever? Just tryin to get some other opinions before i rebuild the diff and find out that it was something else.
Thanks guys

 

[bhuff30]

A carrier bearing isn't very likely. A wheel bearing seems much more likely and those are easier to replace.

 

[stangman11]

The noise does not seem to change at all when turning though which ussually is a sign its a wheel bearing.

 

[joshjwc9]

Wheel Bearings are an easy fix, I would replace the two rear ones, and see if that is your culprit, because of mileage on the car (if it is high). Otherwise if the sound persists you know it is somewhere in the RE. If that is the case, expect it to be a carrier or pinion bearing, and when that is the case pickup a set of gears and Ratech's rebuild kits.

 

[stangman11]

Yea the car only has 65k on it which is why im suprised it has any noise at all. How bad are the rear wheels bearings to do I have done plenty of wheels bearings just none on a rear wheel drive. Once you get the backing plate off do you have to take the diff cover off remove the c clip and pull the axle out to remove it?

 

[bhuff30]

My 88 stang had the rear wheel bearings go out around 70k miles, and that was a tiny 88hp 4cyl. It has more to do with age and useage and age in my opinion. Before I got my 88, it sat for a long periods of time, allowing the bearings to dry up.

The rear wheel bearings aren't too bad, but a little tricky. You have to remove the brake caliper, the rear end cover, then the C-clips, and you can pull the axles out. On these newer cars, you'll have to take special care of the ABS sensor to not damage it (just remove it, then reinstall when you are done). You will need a slide hammer to get the old bearing out. Then, use the old bearing to install the new one, and put everything back together, with the correct amount of rear end lube and friction modifier. A ford service manual, or other service manual would be a great help if you've never done it before.

 

[stangman11]

Hey thanks for the info

 

[wmburns]

A whine could be incorrect ring gear/pinion back lash. It could also be bad bearings (pinion or carrier). IMO, the clue it is NOT the wheel bearings is that the pitch of the whine changes in relationship to the load on the drive line. This indicates ring/pinion shifting as the drive line switches from power to coasting.

The wheel bearings are easy to replace. The Carrier bearings are not that hard to replace esp when everything is already torn apart.

The pinion bearings are much harder. Getting the pinion depth correct and the pinion bearing pre-load correct is much harder.

Here is the other problem. A complete rebuild kit is less than $100. What you have to decide (depending upon your experience) is to attack the problem by replacing the easy items or just rebuild the entire rear end. There is a fair amount of work to drain the diff, remove the half shafts, and replace the wheel bearings. If you are wrong, all of that work will have to be repeated.

On the other hand, an entire rebuild kit requires the pinion bearings to be pressed on/off. Then there is the issue of pinion depth. Ford make a special tool for this. Most ppl simply reuse the same shims and check the back lash and contact area. If it is within spec, congrats! If not, remove the pinion, press off the bearing and change the shims. A long process if you do not have a press.

In my case, I got discouraged and bailed out. Paid $600 for a pro to install a rebuild kit. As it turned out, the only bearing that was bad was the rear pinion bearing (I did not know what to look for to tell which bearing was bad). I could have done it myself.

Interesting learning experience. Helps in writing forum posts.

A side note, diff bearings should last a very long time. Premature failure is likley Lubrication maintenance or abuse.

 

[stangman11]

Thats exactly why I know its the carrier bearings, you notice the change in pitch of the whine when accelerating and slowing down. The noise does not change when turning which is ussually an idicator of wheels bearings and it is more high pitched than a wheel bearing noise. I already have a rebuild kit for the clutch packs, diff cover gasket and oil, Im just going to buy a seal and bearing kit and redo the whole diff, maybe put 3.73 in it that I have lying around but I dont know i commute far for work cant really afford worse gas mileage. Although i dont have a press at home how else would you recommend in taking the bearing off the pinion? I have only rebuilt 1 diff before this and I had a press and a lift at my disposal. This job would have to be done in my driveway.

 

[trombonedemon]

americanmuscle.com has a nifty little how to do it yourself when putting in rear gears, hope this helps!

 

[stangman11]

Nice man thanks alot I'll let you know if I decide to put the 3.73 in it, i mean is the gas mileage that terrible I communte around 80 miles a day round trip, and this is my daily for now dont have the space for another car.

 

[TripleBlk]

A whine could be incorrect ring gear/pinion back lash. It could also be bad bearings (pinion or carrier). IMO, the clue it is NOT the wheel bearings is that the pitch of the whine changes in relationship to the load on the drive line. This indicates ring/pinion shifting as the drive line switches from power to coasting.

The wheel bearings are easy to replace. The Carrier bearings are not that hard to replace esp when everything is already torn apart.

The pinion bearings are much harder. Getting the pinion depth correct and the pinion bearing pre-load correct is much harder.

Here is the other problem. A complete rebuild kit is less than $100. What you have to decide (depending upon your experience) is to attack the problem by replacing the easy items or just rebuild the entire rear end. There is a fair amount of work to drain the diff, remove the half shafts, and replace the wheel bearings. If you are wrong, all of that work will have to be repeated.

On the other hand, an entire rebuild kit requires the pinion bearings to be pressed on/off. Then there is the issue of pinion depth. Ford make a special tool for this. Most ppl simply reuse the same shims and check the back lash and contact area. If it is within spec, congrats! If not, remove the pinion, press off the bearing and change the shims. A long process if you do not have a press.

In my case, I got discouraged and bailed out. Paid $600 for a pro to install a rebuild kit. As it turned out, the only bearing that was bad was the rear pinion bearing (I did not know what to look for to tell which bearing was bad). I could have done it myself.

Interesting learning experience. Helps in writing forum posts.

A side note, diff bearings should last a very long time. Premature failure is likley Lubrication maintenance or abuse.

Good observations, wmburns.

I just had my carrier bearings replaced by mechanics I trust. They told me that the left side carrier bearing "peeled" and self-destructed !

I had "rumbling" just like the OP. I kinda guessed there was a bearing going bad in the carrier, but wasn't sure whether it was the pinion , or the carrier bearings.

While they were in the carrier, they replaced the pinion bearing. These mechanics are old school pros who really know their way around differentials. I would attempt any mechanical repair but this.

I wonder if there is a fault in the parts/design of the carrier bearing. The Ford 8.8 has a good reputation, but ...