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Front Differential Leaking On My 02

E

eagledriver

GUEST
My 02 has been serviced a number of times for the differential leaking on the outside end of the housing. I just put the Predator in. Should I unprogram the computer before I service the truck (3rd time) I'm at 35,780 miles so it under the base bumper to bumper.
 
I would not think they would access the ecm during this repair unless they are just nosey - I can see no way they would know if it was programmed or not unless they scanned the ecm. If you are worried then go ahead but it should not matter for this find of problem. If they ask I would ask why it should mater on a leak?
 
clock is ticking at 35,880!!! I got some traveling today. I'm going to drop off the truck at 35,999!!!!
 
I have the same leak problem, but I'm way out of warranty. (53,100 mi). Is there no fix for it or is your dealer incompetent? I'm thinking of treating it from the inside with an additive.
 
eagledriver said:
My 02 has been serviced a number of times for the differential leaking on the outside end of the housing. I just put the Predator in. Should I unprogram the computer before I service the truck (3rd time) I'm at 35,780 miles so it under the base bumper to bumper.
Click to expand...

It seems there are a lot of problems with the front differentials on the '02 model. :6: I would push hard, especially with the mileage for a rebuild. :0: I'm 99.99% sure there is a TSB out on this issue.
 
Mine was leaking, at 25,000, dropped it off yesterday, complete rebuild first time in (bad seal and bad vent, they found the seal issue), picking up in one hour! ?Just tell them what they are to do, PERIOD!

Best to ya!

Mac
 
Dropping it off this morning at the dealer. Let's see what the outcome is this time.
 
They put a flourscent dye in the differential. They could not find the leak as of yet. I am bringing it back this week.
 
Me too. I havent had it repaired, since I found out today. This is a major problem and im glad to have realized that it was leaking before 36,000. I'm currently at 30,850miles.


Pissed as you are,

Rob
 
I have checked the TSB for diff problems and couldn't find any info.
Does any one know the TSB or NHTSA number for this problem :cautious:
 
My 02 had a major differential leak the first week I had it. The dealer thought it was an axle seal and had me leave it while they ordered parts. As they were cleaning the differential to start the job the technician notice there "was a fitting loose". Two minute repair. I didn't investigate further.

This week I had a major leak again. Couldn't get an appointment until Monday so I put her up on the ramps and looked around myself.

There is a black plastic fitting with a hose leading from it on the drivers side of the differential. It's round, about the diameter of a soup can. It has a hex cast in the plastic. In the middle of the hex is a hose barb for the vent hose.

This fitting threads into the housing. There is only about 1/2 inch of thread and they are fine and shallow. There is also an O'ring at the top of the threads. It looks like a hand tight arrangement. The threads have so little bite on the housing the fitting can simply pop out. It pretty much stays in place so a quick look would lead you to think there was nothing wrong. The oil that leaks out blows down and back over the axle, leading people to think the seal is gone.

I'm going to talk to the service department tomorrow to see if GM has a better fix for this problem. It appears to be fairly common. One service tech told me they've worked on 30-40 of these complaints. I don't think repacing the fitting with the same one will do any good unless the problem started with overtightening on assembly.

The same service tech told me they started wrapping the threads with teflon tape to build them up to give a little more grip. That's what I did today. It threaded into the housing until I turned it just a little too far, pop, out she came. I threaded it back in and stayed just shy of too tight. Still a short term fix.

Both problems occurred during cold weather, maybe it's an expansion/contraction issue.

I'll post more when I learn more.
kw
 
kdubb said:
There is a black plastic fitting with a hose leading from it on the drivers side of the differential. It's round, about the diameter of a soup can. It has a hex cast in the plastic. In the middle of the hex is a hose barb for the vent hose.
Click to expand...
Previously, I've posted a diagram of the front axle. To see it, click here.

It would appear that the fitting you are talking about is item #64 - Front Differential Carrier Vent Hose Connector.

The service manual has a section where it describes how to remove/replace this fitting. To get to it, it suggests raising the vehicle, and removing the left front wheel.

Now, there are two styles, ratcheting and non-ratcheting.

For the ratcheting:

To remove it, it simply states to disconnect the vent hose, and then remove the connector from the differential.

To replace it, it simply states to install the connector into the diff, and tighten it to 18 lb-ft, or 25 N-m. Then reconnect the vent hose.

For the non-ratcheting:

To remove it, disconnect the vent hose, and remove the connector from the diff.

To replace, rotate the propeller shaft until the differential window can be seen through the vent hose connector opening. Then place the alignment arm of the vent hode connector in the 6 o'clock position. Install the connector with the alignment arm in the 6 o'clock position. Tighten to 18 lb-ft, or 25 N-m. Then reconnect the vent hose.


I was hoping that looking at the shop manual would reveal some magic procedure to address this. Guess not.

Hope this helps.

-- SS
 
Hi SS

Thanks for the info. Now I'm sure there is something wrong with the seal. These threads won't take 18ft/lb. Maybe not even 18in/lbs.
kw
 
They found the problem. Vent plug was replaced. Now it should be fine.
 
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