Rear output shaft seal on transfer case is leaking hummer h2

If the 4WD service light comes on when you start your Hummer H2, it could indicate a problem with the four-wheel drive system. This warning light could indicate a problem with the transfer case, the drive shaft, the front or rear differential, or other components of the 4WD system.
It is recommended to take your vehicle to a certified mechanic or a Hummer dealership for proper diagnosis and repair. The service light coming on could be a sign of a serious problem, and it is important to address it promptly to avoid further damage to your vehicle and ensure safe operation.

First check the drive shafts(vibration). Universal joints could be bad. Best to have it off the ground. No pressure from the tires and transfer case/transmission. Service 4x4 has to go on a scanner to get codes. Check fuses first.

Did you jack up the rear end, remove the rear tires and brakes, turn the half shaft and through the hole remove the bolts? there are 4 to 5 bolts holding the halfshaft in the housing

I’m happy to assist further over the phone at https://www.6ya.com/expert/brock_d67526d2a834c47e

NOT THAT HARD IF YOU HAVE SLIDE HAMMER AND A 3 JAW ADAPTER.TO REMOVE REAR OUTPUT DRIVE SHAFT SEAL AND AND NEED A SEAL DRIVER TO DRIVE NEW SEAL IN THE TRANSFER CASE REAR.OUTPUT SHAFT HOUSING.

Likely either the shaft has a wear scar on it that's too deep for even a new seal to compensate for or the bearing that supports the shaft is worn. Other possibility is that the same tech is installing it dry every time he replaces it....you need to put grease on the seal lip so it does not self-destruct before the normal lube can reach it.

your output seal on the tranny or input seal on your transfer case is bad. you have to pull your transfer case to tell. this is a pretty straight forward job. block wheels. put transfer case in neutral. drop front and rear drive lines.diconnect transfer case shift linkage. there is a short commponent connecting the trans to the transfer case. the bolt on either end face each other. remove the bolts to the transmission. the transfer case is heavier than it looks, i suggest getting help. pull back on the transfer case until it will drop down. it will pull out a bit because of the trans output shaft. replace what will probibly turn out to be the tranny output shaft seal and reassemble in reverse order.

just fixed one myself. replace rear output shaft seal on transfer case.

90 percent of the time stop leak does not work. Usually the seal between the transmission and transfercase goes out and forces all the fluid into the transfercase and leaks out the rear seal. Or the tranfercase or transmission breather could be plugged.

You may have pressure build up in the tranfer case and its going out the weakest spot which is the seals.Who changed the seals?Your transfer case may have a blocked breather if fitted

Only way for this to happen on an H2 (AWD) is for something to break rearward of the lockup hub. Take a look at the splines between the intermediate shaft and centerdifferential or even the teeth on the forward sun gear and/or stepped pinion on the center diff.

As long as you have the t-case torn down for repair be sure to upgrade to the new aluminum mode fork (production upgrade to old plastic forks thru end of 2007 or so). You should also upgrade the rear half of the housing to the 2008 version which has a pressed-in rear prop bushing (better bushing and is also replaceable.