Broke my diff today, need help figuring this out
06-12-2005, 12:44 AM
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Broke my diff today, need help figuring this out I 've spent 30 minutes searching this site but could not find a good answer, so forgive me if I did not look long enough.
Today my diff on my 107K mile 98 Formula began making what I can only describe as a noise sounding like a circular saw, a grinding noise at takeoff that becomes a banshee wail at 60 mph or so.. Not sure if its the posi or some other part of the rear end and I'd like to have an idea before taking it to a mechanic. Prior to this recent development,I have experienced the clunking noise while turning that appears to be posi related from other posts I've read.
Last year I changed the gear oil to Poyal Purple w/ a bottle of GM posi additive. At that time, there was only a very small amount of metalic shavings on the magnet inside the cover.
I was planning on ordering a rebuild kit from Thunder Racing, but I now realize the posi unit is not included in this kit, and I don't want to buy the wrong parts.
Are mine the symptoms of a bad posi? Also, what do I look for when I pull off the cover to see if its the posi unit, or will it be pretty obvious?
Thsnks for your help.
Today my diff on my 107K mile 98 Formula began making what I can only describe as a noise sounding like a circular saw, a grinding noise at takeoff that becomes a banshee wail at 60 mph or so.. Not sure if its the posi or some other part of the rear end and I'd like to have an idea before taking it to a mechanic. Prior to this recent development,I have experienced the clunking noise while turning that appears to be posi related from other posts I've read.
Last year I changed the gear oil to Poyal Purple w/ a bottle of GM posi additive. At that time, there was only a very small amount of metalic shavings on the magnet inside the cover.
I was planning on ordering a rebuild kit from Thunder Racing, but I now realize the posi unit is not included in this kit, and I don't want to buy the wrong parts.
Are mine the symptoms of a bad posi? Also, what do I look for when I pull off the cover to see if its the posi unit, or will it be pretty obvious?
Thsnks for your help.
06-12-2005, 09:35 AM
#2
It will most likely be the differential. When I had problems with the 10 bolt, the bearings went first. It was a howling noise and it would happen on acceleration and deceleration. When the differential went out, it was a grinding noise and the spider gear were cracked. You are now at the crossroads with your 10 bolt. I would not put that kind of money into the rearend. By the time you purchase the install kit, differential, oil and labor you will be over $1,000. You could pick up a used 10 bolt and just swap them out or you could put te money towards a 12 bolt.