8 3/4 pinion seal question

Anonymous · Post by **Anonymous** » Wed Jan 17, 07 6:30 pm

i need to order a pinion seal for my axle but i am not sure what one i need, all i can find are two big no.2`s cast into the housing. is this enough or are there more no.s somewhere?

Ashley · Post by **Ashley** » Wed Jan 17, 07 7:01 pm

Sean,
On the side of the diff housing there should be a row of numbers ending in one of these 489 / 742 / 741

Pete · Post by **Pete** » Wed Jan 17, 07 7:50 pm

If it is a 489 I think you will have problems as you would have to disturb the crush washer (and thus Pinion depth) when you undo the big nut and remove the Yoke............

Mick70RR · Post by **Mick70RR** » Wed Jan 17, 07 8:08 pm

Pete, the pinion depth on a 489 is set by shims just like the 742, it's the bearing preload that has to be reset with a new crush washer. Not easy to do on the car because the pinion only turns a few degrees before the backlash is taken up and the axles start moving.

Anonymous · Post by **Anonymous** » Wed Jan 17, 07 8:31 pm

I read in a manual you can reset the preload by takin off the prop, wheels and brakes, measuring the preload with an inch/lb torque wrench, then when you put it back together set it back up to that figure.....It says in me workshop manual that the crush washer need only be replaced if you go over 210 lb/ft.

Mick70RR · Post by **Mick70RR** » Wed Jan 17, 07 8:39 pm

I used the same crush sleeve when I change the seal. It was a well used axle and the pinion bearings were worn anyhow so the crush sleeve needed to be crushed a bit more to set the preload.

Anonymous · Post by **Anonymous** » Fri Jan 19, 07 9:01 pm

Ashley wrote:Sean,
On the side of the diff housing there should be a row of numbers ending in one of these 489 / 742 / 741

witch side ashley?
thanks

Ashley · Post by **Ashley** » Fri Jan 19, 07 9:23 pm

Think its the drivers side fella, a row of raised numbers cast into the diff housing

Kev · Post by **Kev** » Sat Jan 20, 07 1:00 am

sean68charger wrote:
Ashley wrote:Sean,
On the side of the diff housing there should be a row of numbers ending in one of these 489 / 742 / 741
witch side ashley?
thanks

That is LAZY! Just get under and have a look, if it ain't there look on the other side!

Anonymous · Post by **Anonymous** » Sat Jan 20, 07 2:06 am

Kev,Sean may of eaten too much,don't be so harsh.

Anonymous · Post by **Anonymous** » Sun Jan 21, 07 6:33 pm

Adam68 wrote:Kev,Sean may of eaten too much,don't be so harsh.

yep a bit of a fattie me!!!

seriously, there is a load of crud on the diff, just wanted to know where abouts to wire brush

Ashley · Post by **Ashley** » Sun Jan 21, 07 6:37 pm

Lower drivers side of the diff housing

Kev · Post by **Kev** » Sun Jan 21, 07 7:38 pm

If it's LHD!

Anonymous · Post by **Anonymous** » Mon Jan 22, 07 9:01 pm

i found them, it ends in 742

are these good 8 3/4`s?
am i right in that the seal is easier to change on this type?
also i have a pinion seal for an 8 3/4 but no part no. but the no. on the seal itself is 15305,
also, if someone has a pinion seal for a 742 dif could they post the measurements in metric for me as i can measure the one i have to see if it is the right one
thanks

Ashley · Post by **Ashley** » Mon Jan 22, 07 9:09 pm

742 sorted

that's what i have, there the LARGE pinion type,
With shims for pinion adjustment, instead of 489 chrush tube type

The outer seal size is the same for all 8 3/4's its the inner you have to measure, just pull the yoke and try it in your new seal