Ron
Enthusiast
Pinion bearing toasted - Anyone have an extra Limited Slip tag?
During a repair, the limited slip tag cracked. 10 degree temps probably contributed. Anyway, not a part numbered item so am looking for someone that might have a extra that they are willing to sell me.
As to why the diff was out, I noticed a rumbling noise that was speed dependant only, i.e. gear selected, on or off power, etc., had no impact. It sounded like it was coming from the trans, but wasn't sure. Got worse over the summer. I was fortunate enough to have Tom Sessions in town and he quickly and correctly diagnosed it as a bad pinion bearing. Tom's the man!
Since I have a lift, too much time and a never ending curiousity, I pulled an oil sample which was non-conclusive as the real self destruction had yet to occur, (iron @ 174ppm w/ 10k miles on Mopar oil). Then I listened with a mechanics stethoscope to the trans, rear and wheel bearings while running it on the lift. The diff was the noisiest of the bunch but what's normal to my untrained ears? I then decided to isolate the diff by removing the driveshaft and running it on the lift again. The wonderful sound of silence! Since I knew that wheel bearings were good, it had to be exactly what originally Tom diagnosed it to be. He took 5 minutes and I took 90, but I probably had more fun.
Anyway, it seems that even three fluid changes over 26,000 miles can't compensate for what in theory was excessive bearing pre-load when originally built. That's what probably caused the bearing race to spall and my unwanted noise. All of the other 5 bearing were perfect. Doesn't take much of an imperfection to make a lot of noise:
.
During a repair, the limited slip tag cracked. 10 degree temps probably contributed. Anyway, not a part numbered item so am looking for someone that might have a extra that they are willing to sell me.
You must be registered for see images attach
As to why the diff was out, I noticed a rumbling noise that was speed dependant only, i.e. gear selected, on or off power, etc., had no impact. It sounded like it was coming from the trans, but wasn't sure. Got worse over the summer. I was fortunate enough to have Tom Sessions in town and he quickly and correctly diagnosed it as a bad pinion bearing. Tom's the man!
Since I have a lift, too much time and a never ending curiousity, I pulled an oil sample which was non-conclusive as the real self destruction had yet to occur, (iron @ 174ppm w/ 10k miles on Mopar oil). Then I listened with a mechanics stethoscope to the trans, rear and wheel bearings while running it on the lift. The diff was the noisiest of the bunch but what's normal to my untrained ears? I then decided to isolate the diff by removing the driveshaft and running it on the lift again. The wonderful sound of silence! Since I knew that wheel bearings were good, it had to be exactly what originally Tom diagnosed it to be. He took 5 minutes and I took 90, but I probably had more fun.
Anyway, it seems that even three fluid changes over 26,000 miles can't compensate for what in theory was excessive bearing pre-load when originally built. That's what probably caused the bearing race to spall and my unwanted noise. All of the other 5 bearing were perfect. Doesn't take much of an imperfection to make a lot of noise:
You must be registered for see images attach
You must be registered for see images attach
.
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