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Sierra diff Pinion seal change ?

tilly819 - 2/10/11 at 08:43 PM

Hi all

I have a leaking pinion seal on my searra dif, going to change it in the next couple of days but have nevr done one before.

i assume you take the big nut off the front of the diff then that allows you to remove the flange and gain access to the seal, is this correct??

i would like to do it without removing the diff from the car ideally. is this practical and does anyone have any tips or advice on how to do it>?????????

many thanks
tilly

britishtrident - 2/10/11 at 09:13 PM

Stop ! and find out more before you disturb the pre-load adjustment.

First check the diff isn't over filled -- level should be just below the filler plug level when the car is sitting absolutely level, also check the breather is clear.

If you must change the seal then the in service procedure (bodge) is to mark the angular position of the nut on the pinion shaft and undo the nut counting the turns exactly, remove the flange and hook out the seal. Replacement is exactly the reverse procedure it must be stressed the nut must be screwed on exactly number of turns or the diff crushwasher will require replaced.

tilly819 - 2/10/11 at 09:23 PM

thats great advice thanks, the seal needs changing for sure, thats great info about the pre load, i will mark the nut before i undo it and make sure it goes back on with the same number of turns

tilly

britishtrident - 2/10/11 at 09:23 PM

I found this vid on Youtube it shows how to do it

mcerd1 - 2/10/11 at 09:31 PM

Chippy - 2/10/11 at 10:38 PM

Just to clarify, the nut holding the drive plate does not have anything to do with the pre-load. When removed you will see another nut behind the drive plate, this is the one that is adjusted for pre-load. So just remove the drive plate fit the oil seal and then redo the nut to the correct torque, (which escapes me at the moment). HTH Ray
Edit to add, if you look at the picture in this link you can see the nut, No6, (which is left hand thread), behing the drive plate.
http://i5.photobucket.com/albums/y170/mcerd1/page01.jpg

[Edited on 2-10-11 by Chippy]

[Edited on 2-10-11 by Chippy]

Dusty - 2/10/11 at 11:19 PM

I thought my diff had a leaking pinion seal due to the diff oil smothering the nose. Carefull investigation showed the oil was leaking between the splines of the prop flange and the pinion and not the seal which seals round the outside of the prop flange. I couldn't work out how this was intended to be made oil tight.

bigbravedave - 3/10/11 at 07:01 AM

mine was leaking, but also from the flange not the seal, a tiny smear of sealant on the flange did the job.