Help!! I need to know how much torque to use when restalling the companion nut on the pinion shaft. I had a leaking front seal which I replaced but didn't think to check the torque on the nut before removing.The manual's I have do not give any information except to tighten to realign to marking's made prior to removal.
-
-
Re: C3 Rear End
In general, I would never use the torque required to break a nut free as any indication of the torque required for re-installation...the mechanical reaction to tightening versus loosening will be different, plus you have the unknowns of lubrication, corrosion, etc. In this case, if you forgot to mark the flange/pinion shaft and nut, this rule is even more applicable.
I haven't done a differential overhaul, but the overhaul manual indicates no torque value because the torque is only what is required to set the pre-load on the pinion bearings (opposed tapered roller bearings). Since the pinion is installed in the housing FIRST, that torque using old parts is specified as 5-15 INCH-pounds. For new parts, that is new bearings, shims, nut, that pre-load torque is 20-30 INCH-pounds. I believe that means that if you forget to mark the flange/pinion shaft and nut, there is no good way to get back there without tearing the differential all the way down to the case with the installed pinion.
In your position, I would probably make every effort to discover evidence of the original pinion nut staking/locking, and consider putting the nut back to hand-tight plus the rotation necessary to get it to the original staking position. If I wasn't absolutely satified that result was correct, I would reluctantly choose another door. -
Re: C3 Rear End
Thanks Chuck:
I did mark the nut& flange. However I did not remember how many rotation's it took to remove nut from shaft. A test drive around the block seemed OK but I want to make sure all is right before cruising.Comment
-
Re: C3 Rear End
Typically when replacing the pinion seal you mark the nut/pinion location so it can go back there. It is almost impossible to get a torque wrench on the pinion nut with the Diff in the car. The bearing preload is set to in/lbs not ft/lbs- UNLESS there is an aftermarket solid sleeve in place of the stock crush sleeve. If the diff has never been overhauled and even if it has most rebuilders do not use the solid sleeve.
With that said, as long as you did not over crush the sleeve with an impact gun the yoke will stop up against it and the nut should be very close to the marked position. If it was too loose the pinion would hit the case and you would hear it very quick letting off the gas. If you have overcrushed the sleeve the preload will be tighter- just how much tighter I could say as it would depend on much over crush was applied. If you haven't noticed any odd noises and the car feels ok then you're probably ok. There's not much you can do at this point so I would drive it a bit and listen.
I have found some housing with a different bore depth for the seal and this will affect the gap that is normally left between the housing and seal flange. I had one where the flange was up against the yoke and gave me a false reading on the rotational drag. I had the cut the flange off to use it in that one.
Also did you use #2 on the yoke ID splines and Ultra Balck on the seal OD? If you didn't you will have a leak from under the nut as the oil works its way up the pinion and out. Another area to check is the OD of the yoke hub where it fits against the seal. This will wear like a harmonic balancer and there is a speedy sleeve that fits it.
Good luckComment
-
Re: C3 Rear End
My NOVICE opinion is that you are OK.
If I had marked the flange and nut, and the nut came back to that mark with slight resistance, I would be satisfied with that result. Five to fifteen INCH pounds AIN'T MUCH!, but with the ring gear installed the resistance would be more. I still don't think the screw lead would allow you to be off by a full turn. Like wheel bearings, the 5-15 INCH-pounds is essentially to insure all free play has been removed from the bearings and pinion assembly in my opinion.Comment
Comment