87IROC92RS

As stated in previous posts I have to change the rear pinion seal in my 87 iroc. The haynes manual was sketchy at best as to the removal and re-installation not to mention it didnt specify the preload on the differential yoke. Anyone ever done this and know the specs on it? The way they ran my exhaust plays hell on taking the driveshaft out so im limited to moving it as far away from the yoke as I can and wrench access is limited. Any info you guys could give me would be greatly appreciated

gurkgurkgurk

it requires you to take off the wheels, wheel bearings rotors, open the diff, take off the pin holding the spider gears, push in the axles and take off the c clips, take off the axles. drop the rear end, put it on a bench(a diff holder works best) take out the case, measure case bearing preload with a inchpound torque wrench, take off the nut, pound out the pinion, replace bearings, crush sleeve, oil seal, put it all back measure case bearing preload again.

in a nutshell

calebzman

iTrader: (3)

That seems like a lot of work for just a seal, but it's probably the correct method. When I changed my yoke & seal on my 9 bolt, I removed the pinion nut, used a puller to get the yoke off, removed the old seal, put the new seal in, put the yoke on, and tightened the nut until it was snug.

I think I read somewhere that the preload on the pinion nut is 15in-lbs, which is a little over 1ft-lb. I took that as 'snug' with a 3/8" ratchet after bottoming out the crush sleeve.

gurkgurkgurk

that would cause a preload problem, since when you pull off the yoke, you took the load off the crush sleeve, and then tightened it back up again. and its only meant to crush once. after once, you have to get another one. the way you did it would risk premature wear of the pinion bearings, and ring and pinion gears. especially if you didnt check for pinion bearing preload. i would say that i would do the same if i was broke, and just wanted to get it out of the way.

87IROC92RS

not to sound ignorant but the oil seal ( as its called ) has a new crush sleeve in it as well as a silicone ring around it to ensure it doesnt back out ( Napa ) but I dont have the space to completely remove the rear axle, yet on the same side I dont want it to leak

//<86TA>\\

iTrader: (14)

you can't get the crush sleeve on without removing the pinion gear from the rear, which requires a complete tear down

as for replacing the pinion seal, its a piece of cake, no tear down necessary.

you heed to mark the big nut that holds the yoke on. It has to go back on exactly where it came off. count threads too if you can. After you get the nut off, the yoke may just some right off, no puller needed. Mine did. After that the seal is just pressed into the housing, look at it and you will see the little flat ring that sit up against the housing. i used a thin flat screwdriver, and tapped it between the seal and the housing, working around the entire seal and worked it out. then install the new one and carefully tap it back in with a dead-blow hammer or some other forgiving tool, alternating sides to work it back in evenly. Then re-install the nut back where it was.

Might not be very technical, but thats how many people here have done it, including myself and had no problems at all.

you will loose all the gear oil when you pull the seal out so be prepared, Im sure it needs to be changed anyway.

big gear head

I'm new to this sight, but I have 26 years of rear end experience. First, you need to know why it is leaking. Many times a pinion seal will leak because one of the pinion bearings is bad. It could also be leaking because the yoke has a groove worn in it. If this is the case then you might need to replace the yoke. Sometimes the pinion nut will back off a little, which will allow the seal to leak.

If the seal is the only problem then you can remove the yoke, replace the seal and put the yoke back on and torque the nut to about 125 foot pounds. This is not enough torque to crush the spacer and change the bearing preload, but it is tight enough to support the pinion gear. Be sure to apply some sealant to the outside of the seal before driving it in and use Loktite on the nut.

As for the problem of getting to it, try removing the torque arm, but DON'T do this if you have the car sitting on jack stands under the rear end. When you take the torque arm off it will allow the rear end to flop over.

87IROC92RS

thanks for all the input and taking the torque arm off seems to be the only way unless my exhaust modification allowed enough room to slide the tranny yoke out then pull it out from the front of the car. Either way its going to have to come off to get the proper access to the pinion yoke. Im guessing that it might be the nut backing off since its apparently leaked for a long time ( when I changed the diff fluid there was old gear oil slung all round the underbody of the car around the pinion yoke )