Noise From Rear Drivertrain (2 Viewers)

[Roldan]

I managed to get my cruiser stuck in 3-1/2 foot deep muddy water over the weekend and it developed a very noticeable howling/buzzing noise on the drive home. The next day I changed all the diff fluids and lubed the drive shafts but the sound remained. I drove it in RWD and FWD and the noise goes away when driven in FWD. I did a little searching and it seems that the pinion bearings area a likely source of the problem. The cruiser had a faint drive train howl before this incident and it may have been getting worse over time. Also there appears to be an oil leak where the pinion shaft exits the third member, the rear diff oil was very metallic looking, and my diff breathers are not extended. Am I on the right track with the pinion bearing theory? Is it likely that my ring and pinion are also damaged and I should plan to replace them as well?

Rear Diff Oil:

Thanks!

 

[Kernal]

Did you find anything significant on the drain plug magnet? Is the howl under load, coast, or both, and is it directly related to road speed, the faster you go the louder it gets?? Wait for the experts to chime in.

 

[CJF]

I drove it in RWD and FWD and the noise goes away when driven in FWD.

 

[Roldan]

There were metal shavings on the drain plug magnet but no chunks. The noise happens only under load accelerating or maintaining speed, does not occur while coasting, sometimes occurs under decel. It doesn't get much louder with speed and doesn't start until about 7-10mph. Does not make noise when unloaded at any speed.

I drove it around the block in FWD and RWD by disconnecting one of the drive shafts.

btw - is there a way to edit posts on this board? I didn't proof read my original post too well.

 

[CJF]

Ah: front only and rear only by removing the driveshafts; got it.

Oh, and there should be an edit button under each of your posts.

 

[Dan2722]

Sounds and looks like some mud and water got into your diff. Do you have the extended diff breather in the rear?

I would do a short period flush of the differential by running it a few hundred miles and then drain and refill with fresh fluid to see if the noise goes away.

 

[Roldan]

I don't think I can stand to drive it a couple hundred miles, so I ordered a pinion bearing kit and dropped the third member. I've studied the relevant sections of the FSM and I think I'm starting to understand the job. Does anyone have a good idea for a tool to push the new inner bearing on? The old bearing perhaps?

Third member was easily lowered using a floor jack, last time I used my face. Lesson learned.

Ring gear looks OK to me

 

[Roldan]

Changing the Pinion Bearings and cleaning out the old fluid did eliminate the really bad noise. There is still a bit of whine/howl but nothing worse than before the mud puddle.

 

[Akella]

How hard is job to change the bearings? What tools you used? I will probably tackle this job in the spring.

 

[Roldan]

The job wasn't too difficult, getting pinion depth correct could be troublesome if you have to keep pressing the Inner Pinion Bearing on and off a few times. It looks like you have E-Lockers so the carrier bearing process is slightly different for you. Your carrier bearings are adjusted by shims instead of threaded adjustment nuts.

Important Note on Pinion Depth (Use an OEM Inner Pinion Bearing):
I read that re-using the existing gears and Depth Shim would eliminate the need to check pinion depth. I began working under this assumption but then realized that my aftermarket Pinion Bearings may not place the Pinion Gear in the same place. I didn't have any other shims to adjust this so I just went for it anyway. It looks like the Pinion Gear is a bit shallow. The "regular" howl/wine noise may not even be curable with the correct shims given the age of the ring and pinion set so I will leave it as is until I re-gear or it starts to make an awful noise again.

Tools Required:

• Basic Socket Set, Click Torque Wrench, Combination Wrenches
• Pry Bar
• Screw Type Puller
• Gear Puller
• Brass Hammer and Drifts
• Bearing Race Install Discs
• 54mm Toyota Front Hub Socket (to drive companion flange seal on)
• Aluminum Tube
• Hydraullic Press
• 1" Flat Bar with Two 8mm Bolts
• Dial Indicator with Holder
• Beam Type Torque Wrench
• 3" x "3 Angle Iron with Holes Drilled to match Companion Flange

Parts:

• Inner and Outer Pinion Bearings
• Pinion Bearing Depth Shims
• Red Lead
• Diff Carrier Seal
• Axle Shaft seals

For more detail: Toyota Differential Pinion Bearing Replacement > Discussions > Northwest Overland Society

 

[Frankencruiser]

Pictures of the bearings?

 

[Roldan]

There was no visual damage to the bearings. My theory is that one of the pinion bearings gained some extra radial clearance causing the improper mesh of the ring and pinion. The noise was likely due to the poor mesh.