Pinion seal replacement

[1980]

I've done the search, read all I can find and decided to try the "mark the nut position" method. They raise the rear and apply the E-brake and proceed.

My question, Is it necessary to raise the the rear off the ground?
My E-brake is disconnected, so I'm unable to lock the diff to remove the nut. Can I follow the same procedure on the ground?

79 GMC K1500

 

[euzoa]

the best way to make sure you have the right preload on the forward pinion bearing is by using a beam type torque wrench, see at what torque it releases and re-torque it to that. if you don't get the preload right you can fry that bearing really quick.

if someone else has done the "mark the position" method maybe they can help better, but the idea behind having the truck in the air is to take the majority of the load off the ring gear/pinion

 

[jeff in co]

I've done the "mark the nut" method with success but have only done it once. I would probably feel more comfortable, as a confirmation check, to jack the rear end up off the ground, remove the wheels and drums. That way you don't have any other "drag sources" other than ring/pinion/axle shaft/wheel bearings. Before removing and marking the yoke and nut, I'd take a beam type torque wrench and find out what values you get as-is. Then after you replace seal and re-install yoke, you have a number that might instill more confidence that your pinion nut is close to the same position as before.

Other here will tell you no, and it's not the correct way. I totally understand and agree, but all I can say is mine stayed together fine. It was a little concerning though....

 

[Bowtie85]

I've done multiple mark the nut Methods before. No problems either.

 

[paratrooper307]

The mark the nut method worked fine for me. I did not jack up the rear end.

In order to measure preload properly, you actually have to disassemble the axle, including axleshafts and carrier. That is the "correct" way, but its also a lot of work, particularly when being careful you can replace the pinion seal in about 15 minutes by marking the nut. I don't think these axles are as sensitive as some make them out to be, but you'll want to be careful.

 

[rebelgregory]

The beam-type torque wrench method won't give you the correct pinion preload (factory recommended numbers). What it will give you is a baseline 'as-found' number so that when it goes back together, you have a basis of comparison to know it's close to how you found it. You just remove the drums and wheels to ensure that all the variables are eliminated.

I did the nut-mark method with the torque wrench. In the end, I ended up going about 1/8th of a turn past the original mark to restore the preload to the as-found number. It probably would have been ok without it. But it gave me a lot of peace of mind that it would not grenade afterward.

It's up to you, but this is what I did. If I were doing it again, I'd still use the torque wrench. Mainly for the 'peace of mind' part.

.

 

[diesel4me]

There is a specisl tool to hold the yoke still while you tighten the nut,basically its just a bar with a hunk of flat stock welded to it with a cut out to fit around the yoke..but you'll be hard pressed to find one,maybe a dealership has one..

I've used a large pipe wrench a few times as a suitable substitute though,to hold the yoke from turning as you tighten up the pinion nut..

I've seen a dozen or so pinion seals changed at shops,and most of the guys just used an air impact wrench..I know thats supposed to be taboo,but they have been lucky--none came back with trashed pinion bearings or gears yet..

 

[dangerdog]

As long as you do not over tighten and crush the crush sleeve anymore you should have the same preload. And it takes alot of torque to do so. As long as the yoke is tight then the nut is tight enough. You are not tightening the nut down so it does not fall off. Usually they are a flanged or locking nut.

 

[magik235]

I have used the mark the nut method several times on a variety of vehicles.

 

[dyeager535]

If using the mark the nut method, no reason you can't do it with the tires on the ground. You aren't measuring preload, and that's the only reason it would need raised.

If you can get a beam type wrench (Autozone loan?) I might just do at least the preliminary preload check, so *IF* when it's back together, and the gears howl, you know what you need to do to get it right.

As with others, I've done it "wrong" without using preload, and have been lucky most of the time, but have had one that howled afterwards. I don't drive that car so it's not an issue right now, but eventually will need re-done correctly.