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Discussion Starter · #1 ·
Well after getting my 9" set up again with an OEM gear set and new bearings etc. I take the car out at lunch and notice a loud whine at 60mph. Definately sounds like gear whine, stops after I let off the gas. So I jacked the car up tonight and dropped the drive shaft and I'm very sure the pinion nut has backed off. It was flipping tight (backlash) when set up and feels real loose now. This was a brand new pinion nut, and crush sleeve.

Can I just torque this back tight and hope for the best ? I did this on the 12 bolt in my chevelle some years ago after changing the yoke and it was ok, but ....

Plus how to insure this doesn't happen again ?
 

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Snug it back down, this time using some red Loctite on the nut to make sure it stays where you put it.
 

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I has the same exact thing happen to and our recently retired resident rear end specialist BIG GEARHEAD told me to simply trq the pinuon nut back down to approx 125lbs using loctite on the nut.

He told me approx 125lbs trq on the pinion nut was not enough to crush the sleeve anymore but it was tight enough to hold things tight and to pull the pinion up to approx the set point it had pruor to comming loose in most cases.

Mine has been fine for over a yr now since doing that so hopefully you didnt do any damage to your's either and you can juswt follow this same advice he gave me.

scott
 

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Discussion Starter · #5 ·
I think God is punishing me with this car, perhaps I should have never sold the Chevelle.

Torqued the pinion nut down to 150 ft-lbs and there is no change, same amount of excessive backlash. Really need someone like BGH to chime in who knows 9" rears. I have no idea could the ring gear and carrier have shifted away from the pinion ?

Crap, now I suppose I have to wait until sunday when the guys gets back, who set the rear up in the first place. :(
 

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I'm by far no expert, but i did just finish my first carrier/gear change with help from an expert thru this site and emails!.....are you sure the person who set it up really knows their stuff.....you need a dial indicator to measure the backlash, & you need to know what it is....it is a combination of pinion shim & carrier shims.....red loctite on the nut is crucial & tricky, because you need to put some gear oil on the washer to prevent galling, yet, have the threads on the pinion shaft & nut totally clean, so the loctite will hold....easier said than done....you may want to try a new nut also......I also punch peened the side of my nut when done & filed a line on it & pinion end, filled with white paint, so periodically i can crawl under and easily visually check if the nut has moved at all.....but again, i am no expert
 
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