Hi all,
Have a rather leaky pinion seal on my sierra diff, is it possible to change easily ?? remember somebody telling me about having to preload bearings when replacing or something like that.
Also going remove rounded off drain plug while diff is out, anyone know where to get new plug from other than Mr Ford ??
thanks in anticipation

If you mark the position of the drive flange relative to the pinion shaft and the position of the flange securing nut relative to the shaft and flange you should in theory be able to replace the oil seal and refit everything back to its original position without affecting the preload. IMHO
As for removing the siezed plug , weld a large nut onto the plug, the heat will loosen the plug and being able to apply torque to the plug , remove it. Don't think I would bother with a new plug as they all sieze. Some motor factors can supply sump plugs which may be suitable for a diff, after all its just blocking off a hole, theirs nothing special about it. HTH
PS Do you need to remove the diff just to change an oil seal???

Thanks for that I think I'll go for it whats the worst that can happen !!! already got diff on the bench only took half an hour to get out, space under the car at a premium.
Managed to get diff plug out much easier on the bench, glad I did judging by the colour of the oil that came out !!
Cheers again