Pinion Gear bearing preload

[petro]

Can anyone advise on the procedure of tightening of the pinion nut on a Mk2 late diff with a collapsible spacer ? I have consulted the manual 51.25.19 (item 26) and read at length Don Kennedy`s well presented rebuild of the diff all of which refer to the earlier diffs with shims against a solid bearing spacer (non collapsible) on the pinion gear .
I am assuming with a new collapsible spacer that I just check pinion preload (15 - 18 Ibf ins ) whilst torquing up the pinion nyloc nut to between 90 to 120 Ibf ft which will slightly crush on the collapsible spacer and still give me the correct preload - as no shims are on the existing pinion shaft when i took it apart??

[martin]

imported post

Hi Petro, and welcome to the forum. I've not done a Stag diff (yet) but I have done Scimitar Salisbury diffs, also with a collapsible spacer. Blindly following the torque figure is a mistake, try and set it a little tighter than a wheel bearing, i.e. only just no backlash,then a tiny fraction of a turn, if you even slightly over tighten, you will knock out the bearing before you can do anything, the whining will let you know. Good luck Martin.

[tonypy1]

imported post

Sounds right, you'll just crush the spacer until you have the correct preload. Much the same as with the hub bearings, the only difference being you can check the endfloat with the hubs but not with the pinion.

[flying farmer]

imported post

Forget torque figures. These collapsible spacers crush very easily. Just tighten it genltly until any endfloat has gone, a fraction more and you will feel the pinion bearings going tight. Don't overdo it.

It is possible to rescue an over crushed spacer by knocking down the centre bulge which re lengthens it and then trying again. Well, it worked for me

Neil