front differential seal replacement

[gnjeff.t]

Re: front differential seal replacement

There is no sign of a leak. I replaced the input seal a few years ago. Still looks dry. I did the same procedure for the removal of the input coupler then as I noted earlier. I don't think i will mess with the input seal at this point, but i will keep an eye on it. It's kinda funny to talk with people from back east, no offense, but the states back there are a little closer together than they are out here. California is more the a 12 hour drive from north to south. It looks like you are in Santa Rosa. My son went to school over there for a while, and i have a few buddies in Sebastapol (not sure of the spelling). I live in a little farming town north of Woodland.

 

[gnjeff.t]

Re: front differential seal replacement

OK, so I'm looking at this thing on my bench and I am wondering if it could be installed without the axles installed. It seems that would make the installation a lot easier. I have already drained all of the fluid, so that would not be an issue. I can't think of a reason why installing in pieces or section would not work.

Any comments or suggestions?'

Later, Jeff

 

[Don W.]

Re: front differential seal replacement

I would recommend Installing the axles. I've never had them out with the dif still installed but replacing the pas side might be tricky. On the install, once you have the dif past the lower a-arms the flanges are not in the way anyway.

You're close, Sebastopol. Yup, born and raised in Santa Rosa. What town north of Woodland?

So why did you remove the yoke if the seal wasn't leaking?

 

[gnjeff.t]

Re: front differential seal replacement

I removed the yoke because I read in another post it would make it easier to remove the differential.

I live in Arbuckle. It's about 25 mile north of Woodland.

I should have the seals today. I will install them tonight, so if all goes well, I will get it back in the truck.

I will update the post when I am finished, and provide any comments about the installation that I encounter that may help the next person.

Later, Jeff.

 

[syclone0517]

Re: front differential seal replacement

Do you have a dial face inch pound torque wrench?

 

[Don W.]

Re: front differential seal replacement

Although I've done in years past if I were to remove my front dif today I grind away the weld that attaches the bracket that wraps around the support next to the yoke. I then just re-weld it. Makes things MUCH easier. For reasons I cannot explain, on my truck, I have to also remove the entire steering drag-link tie-rod assembly as well. AND it also hits the ends of the bolts attaching the lower a-arms. I remove the nuts and back off the bolts until the ends are nearly flush. All very strange because in years past I've had the dif out without doing any of this.

I don't like removing the yoke unless absolutely necessary because it can upset the pre-load on the pinion bearing.

 

[gnjeff.t]

Re: front differential seal replacement

Do you have a dial face inch pound torque wrench?

I do.

I will be re-installing the yoke nut to it's original position, then double checking the drag on the assembly.

Do you know what the drag numbers are?

 

[Don W.]

Re: front differential seal replacement

The Sy supplement does not specify a number. It says to mark the nut, replace it to it's original position, then turn 1/16" beyond that position.

However on a flange replacement they do specify a 3-5 in/lbs. Why one is different than the other escapes me.

 

[gnjeff.t]

Re: front differential seal replacement

When i re-assemble front differential, what sealant should I use on the plate the seal sits in for the drivers side? I removed it to inspect the innards.

 

[Don W.]

Re: front differential seal replacement

What innards? Not much to inspect as you found out. Anyway, Loctite 514 Might have to look around for it. You can try RTV red or black. Just make sure the parts are clean.

 

[syclone0517]

Re: front differential seal replacement

I do.

I will be re-installing the yoke nut to it's original position, then double checking the drag on the assembly.

Do you know what the drag numbers are?

By the book you need to prerecord the rolling torque before removing the pinion yoke nut. Then add 3-5 inch pounds to that when reassembling. For example if you recorded 39 inch pounds before disassembling. you would be looking to have 42 to 44 inch pounds when completed. keep in mind that is with no CV axle shafts connected. for used bearings you should be in the range of 25 to 45 inch pounds. That is pinion and differential side bearings combined. You should replace the nut as well or at the vary least apply thread locking compound. I agree with Don W. Pinion bearing preload is critical to the service life of you differential. Only service that pinion seal when absolutely necessary. It is difficult to get an accurate reading in vehicle.:2cents:

 

[gnjeff.t]

Re: front differential seal replacement

Yep, not much to see when the plate comes off of the drivers side.

Well the job is done, and as I said in an earlier post I would make some comments and suggestions to those out there that are going to this repair (or remove the front differential).

Most of the information needed for this repair was found on this site, and ALL of it was useful. The only issue I encountered was when removing the differential I had the jackstands under the frame. By having them there, it allowed the front suspension to hang down. In this position, the differential would not pass thru the opening between the lower A-arms. So I had to reposition the jackstands under the outside portion on the lower A-arms. With them under the A-arms, and with the weight of the truck on them, the opening between the A-arms was big enough for the differential to pass thru.

I would like to thank everyone who supplied the posts and to those of you who answered the questions I had during this project.

P.S. I went to get the "National Seal" seals from a parts store, they looked pretty weak. After all that I've had to do to get this completed, I thought $17 per seal (part # 14039577) from the GM dealer was cheap insurance for not having to do it again.

Later, Jeff.