Alfa Romeo Bulletin Board & Forums - View Single Post - Differential noise - 74 Spider; 40k miles
View Single Post
post #13 of (permalink) Old 10-06-2017, 12:34 PM
PSk
Registered User
 
Join Date: May 2003
Location: Tauranga New Zealand
Posts: 11,559
Send a message via AIM to PSk Send a message via Yahoo to PSk
Quote:
Originally Posted by BrundleFly View Post
See this post by Papajam for an explanation of why pinion nut torque changes over time, and how to find a good setting when you aren't able to restore the original:

http://www.alfabb.com/bb/forums/1038599-post6.html
Quote:
Originally Posted by Papajam
What happens over time as the bearings and races wear, the torque on the nut gradually gets less and less. If one now retorques the nut, or tightens it good and tight, the bearing pre-load can be so high as to prevent the pinion from even spinning!
The trick to replacing the pinion seal is to first note the torque on the nut before removing the nut. After seal replacement, torque the nut to the previous value (disregarding the torque spec in the book).
I have a lot of respect for Papajam but the pinion shaft has solid spacers all the way so again I cannot see how the pinion nut can affect bearing preload no matter how worn the pinion bearings are. It is vital that the pinion nut is sufficiently tight that the spacers are doing there job. If the pinion preload was set with gaps between the solid spacers then yes the pinion nut torque will alter the preload, but then the diff rebuilder should be fired.

Will keep thinking about this ...
Pete

'71 1750 Series 2 GTV:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
156 Series 1 v6 ... and remember it's all just opinions
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PSk is offline  
 
 
For the best viewing experience please update your browser to Google Chrome