Rhythmic Rear End Noise

Post by **ARCHINSTL** » Thu Aug 17, 2006 11:11 pm

Logbear -
Thanks for trying this and reporting the results. Did the noise sound any different? I'm wondering if it could still be the center bearing and/or the front shaft's U-joint?
Guess I'll try your method before using the Windo-Weld on the center bearing.
Good Luck, and do report your results.
Tom M.

Logbear · Post by **Logbear** » Fri Aug 18, 2006 12:50 am

The noise is exactly the same. And with the rear drive shaft removed, and being in 2WD the front drive shaft wouldn't even be turning, so I'm convinced that it's not drive shaft related.

When I was trying to figure out the noise before I took the driveshaft off I listened to it both in 2WD and 4WD. No difference.

The Toyota repair manual lists 6 things to check for rear axle noise.

1) Oil level low or wrong grade
2) Excessive backlash between pinion and ring or side gear
3) Ring, pinion or side gears chipped
4) Pinion shaft bearing worn
5) Axle shaft bearing worn
6) Differential bearings loose or worn

I checked the oil. It's probably old but it's full.
I've never done any of the other procedures. I suppose it's time to learn. I read in another post about the backlash adjustment. I better start searching.

Post by **ARCHINSTL** » Fri Aug 18, 2006 1:19 am

Logbear wrote:The noise is exactly the same. And with the rear drive shaft removed, and being in 2WD the front drive shaft wouldn't even be turning, so I'm convinced that it's not drive shaft related.

Actually, the drive shaft is turning all of the time, being "driven" by the rear end; in 2WD, there is no power given to the driveshaft by the transmission.
Tom M.

Logbear · Post by **Logbear** » Fri Aug 18, 2006 1:35 am

Yea, but I took the rear driveshaft out so the rear axle doesn't have anything to drive now.

takza · Post by **takza** » Fri Aug 18, 2006 5:57 am

So you removed the driveshaft behind the center bearing?

Typrus · Post by **Typrus** » Fri Aug 18, 2006 12:41 pm

Yes he did. I've done it before as well, though in my case, It was to paint the sucker black. Was tired of the worn color. Did the same to most of my rear axle.
There is a section of driveshaft that can be removed just after the Carrier Bearing and at the differential. Its a couple of feet long.

If that section is removed, the only thing there to drive the front driveshaft section of the rear supply (the shaft that rests in the tranny itself and the Carrier Bearing) is either the transmission, or The Force. The diff can spin as freely as it pleases without affecting the tranny with what was removed.

Post by **ARCHINSTL** » Fri Aug 18, 2006 1:07 pm

Logbear wrote:Yea, but I took the rear driveshaft out so the rear axle doesn't have anything to drive now.

Sorry - I had a "Route 66" moment there...
Tom M.

Typrus · Post by **Typrus** » Fri Aug 18, 2006 3:35 pm

>.<
In my family, my mom calls it "Some-zheimer's" lol

takza · Post by **takza** » Sat Aug 19, 2006 5:53 am

tofactorouttedrivesaftuniversals...soaktheminpentratingoil...thendriveit.

Logbear · Post by **Logbear** » Sun Aug 20, 2006 3:32 pm

It's been a few days now with the driveshaft removed and the noise is still there. The noise doesn't seem to be the same all the time. Sometimes it's more noticable than other times. I was thinking about just getting a better stereo system and cranking it up really loud, but I also feel a vibration so somethings wrong somewhere and I really should figure it out and fix it.

I think I better check the rear wheel bearings more closely. How big of a job is it to replace the rear wheel bearings?

Logbear · Post by **Logbear** » Sun Aug 20, 2006 6:03 pm

After reading a write up in the repair guide section, I swapped the right rear axle with one off one of my parts cars. I filled the diff with new gear oil. The noise is still there. Just the same. The wheel bearings seemed fine on both the noisy car and the parts car, but I changed it anyway just to see if there was any difference. I think I'm narrowing things down to a differential problem. I'm working through my denial. 277,000 miles

Logbear · Post by **Logbear** » Thu Aug 24, 2006 1:35 pm

My denial worked. The only thing I hadn't done was check the left rear axle and what do ya know. That wheel bearing had sort of a rumbly feeling when the wheel was turned by hand. There was no "play" in the bearing like you would find in a "regular" wheel bearing. I swapped it with the axle that was on the right side and voila. No more noise. All this time I had the rear drive shaft off so after the axle swap I left the drive shaft off to check for noises. No noise without the driveshaft and no noise after I put the driveshaft back on. The rear U-joint on the driveshafts I have both have a "not so perfect" feel about them. (They move one way very smooth and the other way with a slight resistance) But the U-joints don't seem to be making any noise or anything.

End result: The wrirring noise I thought was coming from from the middle or right side was actually the left wheel bearing. Thank goodness it's not the differential.

277,416 miles and going strong

Post by **ARCHINSTL** » Thu Aug 24, 2006 4:06 pm

Thanks for the report.
I think I'll try the driveshaft removal first - then your method of swapping the axles. That would seem like a logical procedure, no? My bearings seem OK; at least no wobbling/looseness/roughness detectable by hand rotation/pulling.
Are you going to be replacing both bearings at the same time?
Mootsman (and possibly others) did a write-up on this a while back.
Tom M.

Logbear · Post by **Logbear** » Thu Aug 24, 2006 11:00 pm

I was fortunate in that I had a parts car in the yard and I just pulled the axle off that car. I didn't have to deal with installing the bearing on the axle.

I put the "parts car" axle on the right side of "my car" and the noise didn't change. Then I replaced the left axle with the one that was on the right side. Thats when the noise went away.

I never noticed any play in the bearing, but I did notice a slight "rough" feel, and a little noise, when turning the rear wheel. And now with the old axle off I can feel that the bearing is not good. I don't know how I missed the noise and feel when I first checked them out, but I did. When I had the tires balanced, the tire shop said the bearings seemed fine to them. So they were fooled too. There were times that I thought the noise in the car had gone away and then as I drove it came back. Maybe the gear oil was in the bearing when I would take the car for a drive and kept it quiet for a while and then after a while sorta went dry.

The difference in noise between the "good" bearing and the "bad" bearing was pretty small but it was there.

Fingers · Post by **Fingers** » Fri Aug 25, 2006 9:06 pm

Replacing those rear bearings is a pain. You have to take em to a machine shop to have the old ones pulled off and the new ones pressed on.

ARCH, let me know what you come up with. I should have figured out what I have tomorrow, after I take inventory of all the parts laying around.

Good luck all!