Keep blowing rear diffs

jman11788

jman11788

Member
Ever since I replaced my rear axle assembly with an E locker axle the pinion bearings keep going bad. They typically last about 4 months. However the first couple of times I think I knew the reasoning.

The first time the vent tube was broken with a hole and after a day of diving on the trails through water and that day it started making noise. Replaced the diff and vent tube all is good.

The 2nd time I accidentally drove about 30 miles on the road with the locker engaged. That same night it started makin a slight noise at its peak of 40mph

Now the 3rd time. I've had the diff since January and all has been perfect absolutely no noises and I haven't even engaged the locker yet. Yesterday after driving to the beach for 5 hours it starting making that same noise right at 40mph. That's the only speed it'll whine but I know as soon as this sound starts it gets worse and worse.

So I'm really at a loss here. I've looked for any leaks in the seals and diff and there's absolutely none. Gear oil I used was 75w90 and I know damn sure I'm filling it to the proper level. Is it possible that the drive shaft moving excessively can cause wear on the pinion? Right now when I brake the front end drops down too much as if the rears aren't doing enough. Of course the rears have been replaced recently but maybe the tundra brakes up front make the rear work less?
 
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Are you setting up these diffs, or just sticking used factory built third members into the axle housing?

1) That sounds reasonable - if you got a fair amount of gritty muddy water inside the axle housing, it could certainly ruin some bearings. Generally, not that quickly, but, not too crazy of a scenario.

2) Running the locker on pavement should not cause any issues at all, other than perhaps increased tire wear when you're going around corners. It really is just locking the left and right wheels together, it should have minimal impact on the ring and pinion gears, or the bearings. Was the slight noise enough to get you to replace it?

3) Are you sure the noise you're hearing is coming from the diff? Could be a bad u-joint, or some other component making noise. It's hard to track noises down, they carry, sitting inside the car you have a poor vantage spot to locate where they're coming from.

Is it possible that the diffs you're putting in are worn or damaged before you start using them?
 
JohnMc said:
Are you setting up these diffs, or just sticking used factory built third members into the axle housing?

1) That sounds reasonable - if you got a fair amount of gritty muddy water inside the axle housing, it could certainly ruin some bearings. Generally, not that quickly, but, not too crazy of a scenario.

2) Running the locker on pavement should not cause any issues at all, other than perhaps increased tire wear when you're going around corners. It really is just locking the left and right wheels together, it should have minimal impact on the ring and pinion gears, or the bearings. Was the slight noise enough to get you to replace it?

3) Are you sure the noise you're hearing is coming from the diff? Could be a bad u-joint, or some other component making noise. It's hard to track noises down, they carry, sitting inside the car you have a poor vantage spot to locate where they're coming from.

Is it possible that the diffs you're putting in are worn or damaged before you start using them?
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All the diffs I've used are used ones and not built and were working right at first as they should. 100% sure it's the diff. I'm so familiar with the sound now and what speeds it makes the noise. The noises go away when I replace the diffs
 
What does the oil look like coming out? Have you taken apart any of the bad diffs to see what was wrong with them? Did you clean the rest of the housing really well to prevent contamination of the new oil with old grit/crap?
 
JohnMc said:
What does the oil look like coming out? Have you taken apart any of the bad diffs to see what was wrong with them? Did you clean the rest of the housing really well to prevent contamination of the new oil with old grit/crap?
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I did exactly that. Cleaned everything super good. The oil still looks clean and the gears work but the pinion bearing just get noisy
 
Interesting... have you checked to see if a axle is bent. I don't think a bent axle would tear things up so fast. But obviously there's a problem somewhere
 
And issues with the driveshaft (stuck u-joint, bent, out of balance) would have to be so bad to ruin a pinion bearing that quickly that the car would basically be undrivable.
 
I don't know man, I dont think i'd just throw a used 3rd in there without getting a rebuild kit first. You dont know how many miles are on it or if it was abused etc. A rebuild kit is around $225 I think at Wheelers. Do it right the first time. Good luck.
 
Axles should cause carrier bearing issues. Pinion is usually driveline angle and things forward of the diff.
 
rkntoy said:
Axles should cause carrier bearing issues. Pinion is usually driveline angle and things forward of the diff.
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Out of balance driveshaft? I know tons of us have had double cardon issues without damaging our diffs.

So pinion angle? OP, are you using 9 wraps? How about rear upper & lower control arms not loosened & retorqued after doing a lift?
 
Scramble said:
Out of balance driveshaft? I know tons of us have had double cardon issues without damaging our diffs.

So pinion angle? OP, are you using 9 wraps? How about rear upper & lower control arms not loosened & retorqued after doing a lift?
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Currently running the 8 wraps. All bolts are torqued correctly. The drive shaft could be or of balance, that's the next thing to to check off.

Also the diffs I buy form the sellers claim they have low miles but who knows. Rebuilding is expensive. Even if I just bring the 3rd to a shop the labor is will be steep. But I'm leaning on going to this route next time
 
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jman11788 said:
Currently running the 8 wraps. All bolts are torqued correctly. The drive shaft could be or of balance, that's the next thing to to check off.

Also the diffs I buy form the sellers claim they have low miles but who knows. Rebuilding is expensive. Even if I just bring the 3rd to a shop the labor is will be steep. But I'm leaning on going to this route next time
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yea it is, I paid a very good trans/diff shop to swap my 4.56's into my new e-locker carrier & it cost me $700 & change. They charged me $315 for the rebuild kit & 4hrs ($100hr) labor. I could have saved money by getting the rebuild kit myself online for $225 & bringing it to them. It's also cheaper to buy a brand new diff (non-e-lock) already set up & send in your core but I wanted to keep my factory 4.56 gears & used Timken bearings. You get what you pay for, buy once cry once bla, bla, bla...LOL I hate doing things twice so I just shell out the cash...
 
Housing is bent? Getting a used diff with the housing usually isn't much more anyway. Are you driving abusively? Yeah, weird question. But after ruining diffs in various cars I started realizing and changed my ways.
 
I hope this question doesn't seem redundant but can you clarify what exactly was replaced each of the two times earlier?Axle seals ok, those were replaced.

Replaced to fix the 1st failure, specific parts?

Replaced to fix the 2nd failure, specific parts?
 
T4R2014 said:
Housing is bent? Getting a used diff with the housing usually isn't much more anyway. Are you driving abusively? Yeah, weird question. But after ruining diffs in various cars I started realizing and changed my ways.
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I drive like a grandpa. Wouldn't I be able to feel the way the truck drives if a housing is bent?
 
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BrianSD_42 said:
I hope this question doesn't seem redundant but can you clarify what exactly was replaced each of the two times earlier?Axle seals ok, those were replaced.

Replaced to fix the 1st failure, specific parts?

Replaced to fix the 2nd failure, specific parts?
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Only the 3rd member was replaced absolutely nothing else. Axle seals started to leak a few weeks ago and I got that job complete with new seals and bearings etc.
 
Is it possible the rear driveshaft slip joint has been incorrectly indexed with the u-joint on the front of the rear driveshaft? This can cause excessive vibration that can cause pinion bearing failure.
 
Makitso said:
Is it possible the rear driveshaft slip joint has been incorrectly indexed with the u-joint on the front of the rear driveshaft? This can cause excessive vibration that can cause pinion bearing failure.
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THis could be possible since I replaced the front diff and had to diconnect the front. How do I know if it's "indexed incorrectly"?
 
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