Front differential. Rebuild or replace

[Dan2002]

Hi.

I noticed a leak on my 2002 GMC Yukon Denali coming from the axle seal.

I was going to fully check it when I was home. Because I was arriving at work at that time I saw the leak.

After I got off work I headed home but 10 before I arrived home I heard kind of a rubbing noise coming from the front.

It was like my axles were grinding.

I got home and lifted it up. And decided to remove the front differential drain bolt. When I removed it. It had a lot of metal and dirt on the magnetic top on the bolt.

Now I know there is something seriously wrong with my front differential.

Is it better to replace it with a used one or rebuild it?

Also found a guy online that has a 2004 Cadillac Escalade. And is selling the front differential for a fair price. But I don't know if it's compatible with my 2002 GMC Yukon Denali

 

[swathdiver]

Metal chunks or powder like from an etch-a-sketch? If the latter, such is normal. What exactly is grinding though?

I'm of mind to rebuild what I have. Some are of mind to replace with a used unit, as it can be less expensive and done faster; if there's nothing wrong with it.

 

[ivin74]

Hi.

I noticed a leak on my 2002 GMC Yukon Denali coming from the axle seal.

I was going to fully check it when I was home. Because I was arriving at work at that time I saw the leak.

After I got off work I headed home but 10 before I arrived home I heard kind of a rubbing noise coming from the front.

It was like my axles were grinding.

I got home and lifted it up. And decided to remove the front differential drain bolt. When I removed it. It had a lot of metal and dirt on the magnetic top on the bolt.

Now I know there is something seriously wrong with my front differential.

Is it better to replace it with a used one or rebuild it?

Also found a guy online that has a 2004 Cadillac Escalade. And is selling the front differential for a fair price. But I don't know if it's compatible with my 2002 GMC Yukon Denali

If you plan on keeping it over a year rebuild it or replace it with a new one. If you plan on driving it for a couple of months find a good used one. I have heard horror storys on the junk yard used differentials (they don't last long). Keep in mind very little folks know how to rebuild these diffs correctly. There is a tread some where on the TYF on how to rebuild them your self for a fraction of the cost of a new one or a used one.

 

[Dan2002]

Metal chunks or powder like from an etch-a-sketch? If the latter, such is normal. What exactly is grinding though?

I'm of mind to rebuild what I have. Some are of mind to replace with a used unit, as it can be less expensive and done faster; if there's nothing wrong with it.

It is like powder mixed with gear oil. I felt it with my fingers and didn't feel any metal chunks

 

[SnowDrifter]

Fill it up and see how it's doing. If all is well, the axle shaft seal is a pretty straight forward job.

I bought mine with a bad front diff and kept close tabs on it. Fairly linear increase in nose and metallic particulate until absolute EOL, at which point both grew rather exponentially.

Would have liked to rebuild it, but the front diffs on these things are a pain in the ass to do on account of the case splitting sideways. If you have the tools and the know how, it's a cheaper option and the quality of work is what you make it. I opted for a reman unit as the investment in tools for me to take on such a task was fairly close to the break even point for a swap over.


Is your rig awd or 4wd?

 

[Dan2002]

Fill it up and see how it's doing. If all is well, the axle shaft seal is a pretty straight forward job.

I bought mine with a bad front diff and kept close tabs on it. Fairly linear increase in nose and metallic particulate until absolute EOL, at which point both grew rather exponentially.

Would have liked to rebuild it, but the front diffs on these things are a pain in the ass to do on account of the case splitting sideways. If you have the tools and the know how, it's a cheaper option and the quality of work is what you make it. I opted for a reman unit as the investment in tools for me to take on such a task was fairly close to the break even point for a swap over.


Is your rig awd or 4wd?

It's AWD

 

[CountryBoy19]

Also found a guy online that has a 2004 Cadillac Escalade. And is selling the front differential for a fair price. But I don't know if it's compatible with my 2002 GMC Yukon Denali

I think I saw most of your questions answered except this one. You need to make sure it's the same gear ratio. Look on the RPO codes in the glovebox, GU_ & GT_ codes are the gear ratios. GT4 is 3.73 & GT5 is 4.10 but I think the AWDs had lower ratios so yours should be GU_

Make sure it matches his. That would be a GOOD indicator that they are the same but NOT the whole story. IF his or yours was ever swapped for another ratio (not likely, but it does happen) then code in the glovebox means NOTHING and you need to verify ratios by turning the input shaft and counting how many revolutions are needed to make 1 complete revolution of the output shaft.

 

[Dan2002]

I think I saw most of your questions answered except this one. You need to make sure it's the same gear ratio. Look on the RPO codes in the glovebox, GU_ & GT_ codes are the gear ratios. GT4 is 3.73 & GT5 is 4.10 but I think the AWDs had lower ratios so yours should be GU_

Make sure it matches his. That would be a GOOD indicator that they are the same but NOT the whole story. IF his or yours was ever swapped for another ratio (not likely, but it does happen) then code in the glovebox means NOTHING and you need to verify ratios by turning the input shaft and counting how many revolutions are needed to make 1 complete revolution of the output shaft.

Just checked and it says GT4

 

[Dan2002]

Just checked and it says GT4

Update:

I was going to fill it back up and see what it does. But after starting to fill it. I noticed more metal pieces coming out the drain hole. They were very fine pieces of metal. Nothing too bag. So I just decided to take the front differential. Out.

Managed to get it out. And I opened it up and didn't see any signs on chiped teeth on any gear. I did noticed it has 2 bearings on each side. Both look like they have a little bit play on them. I'm not sure if that's normal.

But definitely one of them looks like it has been burnt or is peeling. It has very fine metal pieces coming out the bearings.

I will have to replace both bearings and I would say it's good to put back together.

 

[Dan2002]

After further inspection of the front differential. I was cleaning all the grease and dirt. And found a piece of metal inside. I took out the drivers side axle seal and found where it belongs. I don't know if this will affect it. And should replace it or continue to rebuild