Cross pin diff

[MrNoo]

Just built up the cross pin diff for my car, all went ok, crownwheel bolted on and all fine, however once installed with the side covers on and torqued up I have a spot where it goes tight, if you turn both output shafts together in the same direction its fine, and if you reverse the travel one side to the other it's fine until a certain point and then it goes slightly tight. I can still turn it by hand and wondered if it was just "newness"
I put the covers on before tightening up the diff housing then took them off again, fitted gaskets and put back on.
The diff was fine when assembled so it's obviously something to do with the output flanges or covers and am slightly scratching my backside as to why.
They are Hardy Spicer S outputs with the split collar and bolt/washer/rubber seal combo.
Any thoughts? Will strip it back down tomorrow to double check everything.

[floormanager]

I rebuilt a standard diff, with Hardy Spicer output shafts. Same thing occurred to me. I put it down to newness too. I asked a retired BL mechanic about it and he was not overly concerned. I ran the engine up before fitting the car and it was fine, even holding one side to push the output to the other one. It's now done 700 miles and all is working well.

[MrNoo]

I rebuilt a standard diff, with Hardy Spicer output shafts. Same thing occurred to me. I put it down to newness too. I asked a retired BL mechanic about it and he was not overly concerned. I ran the engine up before fitting the car and it was fine, even holding one side to push the output to the other one. It's now done 700 miles and all is working well.

I guess maybe worrying about nothing then! Will add that I put new diff bearings on too, there were no shims, we used to shim them up but I believe the new style bearings dont need any pre load, not that they need any, if anything I need a thicker gasket. Will see how I get on, will strip it down just to double check everything and see if I find anything.

[floormanager]

You still need to shim the diff (well i did). I think the new bearings are not directional whereas the old ones were. 1 to 2 thou of preload required

http://www.minispares.com/product/Class ... o%20search

Paul

[MrNoo]

Stripped it all down this morn and it turns out that the one diff output shaft is bent (something I have never seen before so never really checked for runout on!) But there is circa 1/16th of runout when you stick it in a lathe and spin, hence why it was binding. I'm guessing it has been in a car that had been involved in a shunt sometime in it's life. It has obviously been run like that as you can see surface damage if you look very closely at the diff gear face, certainly on one side! So problem found! Many thanks all.

[spoon.450]

Wow....that’s a lot of bend..

[MrNoo]

Wow....that’s a lot of bend..

To be fair I didnt need to put it in the lathe, could see it from just turning the opposing output. Heaven knows how it happened, anyway have found another pair of output so all good!