Loose Pinion
Loose Pinion 01 M6 SS 64k miles
My pinion seal has been leaking for quite some time. Not enough to leave oil marks under the car but the bottom of the housing stayed wet. The last time I took the car out I ran it pretty hard and started hearing a clunking noise from the rear. It was most noticeable when backing up. I finally got time to crawl under the car and check it out today. I figured it was the U-Joints but when I shook the driveshaft the pinion itself would move. The bolt in the end of the pinion was so loose I could turn it a bit with the tips of my fingers. The pinion will move in and out as well as up and down/side to side.
I have limited experience with rear ends. I went to a tech school and set the endplay, backlash, and turning torque on one that was out of a car but thats the only time I have had my hands on one.
I'm guessing just tighten the bolt up won't fix it. I plan on getting a 12 bolt or 9" one day but I don't have the money for it right now.
Thanks for reading. If you know how to fix it so it will last awhile post up
My pinion seal has been leaking for quite some time. Not enough to leave oil marks under the car but the bottom of the housing stayed wet. The last time I took the car out I ran it pretty hard and started hearing a clunking noise from the rear. It was most noticeable when backing up. I finally got time to crawl under the car and check it out today. I figured it was the U-Joints but when I shook the driveshaft the pinion itself would move. The bolt in the end of the pinion was so loose I could turn it a bit with the tips of my fingers. The pinion will move in and out as well as up and down/side to side.
I have limited experience with rear ends. I went to a tech school and set the endplay, backlash, and turning torque on one that was out of a car but thats the only time I have had my hands on one.
I'm guessing just tighten the bolt up won't fix it. I plan on getting a 12 bolt or 9" one day but I don't have the money for it right now.
Thanks for reading. If you know how to fix it so it will last awhile post up
TECH Apprentice
Joined: Dec 2004
Posts: 393
Likes: 0
No I wouldn't just tighten the nut..that pesky bearing preload is kinda important.
Pull the cover and get some break part cleaner, clean and have a look. Hopefully the gears etc.. are in good shape. If so, go to the parts store and get a Federal-Mogul/BCA Differential kit #RA320, order a solid pinion spacer from summit and go to it. Cheap and easy.
At 58k all six bearings in my 10 bolt were pitted
Not saying yours will be, but now is the perfect time to rebuild it. You know the basics, so you know what tools you will need right?
Edit: If the gears and diff are all crunched up. Go get a 10-bolt from a salvage yard...save $$$
Pull the cover and get some break part cleaner, clean and have a look. Hopefully the gears etc.. are in good shape. If so, go to the parts store and get a Federal-Mogul/BCA Differential kit #RA320, order a solid pinion spacer from summit and go to it. Cheap and easy.
At 58k all six bearings in my 10 bolt were pitted
Not saying yours will be, but now is the perfect time to rebuild it. You know the basics, so you know what tools you will need right?Edit: If the gears and diff are all crunched up. Go get a 10-bolt from a salvage yard...save $$$
Last edited by Carter Hays; Jul 26, 2006 at 02:34 AM. Reason: Trashed Gears
Thanks Carter. I will probably end up doing that but...
I opened up the cover today and to my surprise the gears all looked great. The only damage I could find was where the pinion had come back to far and left some teeth marks. I'm guessing the noise I was hearing in reverse was the pinion grinding on the carrier. The pinion didn't seem to be hurt to bad though. No chipped or missing teeth.
I ended up putting a little thread locker on the pinion bolt and tightened it down till it felt like the pinion bearing had some preload. I really just guessed but I tightened it till I could feel more drag on the pinion when I turned it by hand. I checked the mesh pattern and it looked decent. Center-toe, can't remember if thats what it is supposed to be.
After I got everything back together I went for a little drive and ran the car pretty hard in 1st and 2nd. No gear noise before or after. Checked for leaks when I got back and everything looked fine.
I know this wasn't the proper way to fix it but I had other plans for the rest of the week and wanted to get the car back together. I'll be keeping an eye on it. Anyone think it will last for awhile?
I opened up the cover today and to my surprise the gears all looked great. The only damage I could find was where the pinion had come back to far and left some teeth marks. I'm guessing the noise I was hearing in reverse was the pinion grinding on the carrier. The pinion didn't seem to be hurt to bad though. No chipped or missing teeth.
I ended up putting a little thread locker on the pinion bolt and tightened it down till it felt like the pinion bearing had some preload. I really just guessed but I tightened it till I could feel more drag on the pinion when I turned it by hand. I checked the mesh pattern and it looked decent. Center-toe, can't remember if thats what it is supposed to be.
After I got everything back together I went for a little drive and ran the car pretty hard in 1st and 2nd. No gear noise before or after. Checked for leaks when I got back and everything looked fine.
I know this wasn't the proper way to fix it but I had other plans for the rest of the week and wanted to get the car back together. I'll be keeping an eye on it. Anyone think it will last for awhile?
I think youll be okay as long as you didnt set too much preload and burn your pinion bearings up. Dont rely on it lasting as long as a proper setup though. Im sure it will buy you some time though.
