06 H3 Front pinion seal leak.

[H3-Me]

I have an 06 H3 stock with no front end mod's leaking differential fluid from the pinion seal (around the seal and housing mating surface). This seal has been replaced 3 times in a month and a half (2x by selling dealer & 1x by GM dealer). I rolled under the H3 and took a close look at the seal, and while inspecting the surrounding area noticed the rubber mount on the cross member looked torn? Is it possible that the torn/worn cross member bushing could be displacing the pinion output shaft to drive shaft at an angle as to cause the seal to continue leaking. Seal is flat in the housing, no oil appears to be coming from around the shaft/seal. Any experience with this problem? Do I need a new housing? I'm experienced in the service arena, but never on a Hummer. Please help?
Also which is the best bang for your buck as far as front diff. cross member replacements?

 

[alrock]

If your crossmember bushing is toast, your diff may be bouncing up and down causing extra and sudden stress on that seal. It would be wise to check the side diff mounts too to see if they are in good condition.

I'm not the expert on pinion seals, but Reloader and I did my rear one yesterday. He pointed out a groove in my yoke that may lead to future leaks, requiring a new yoke if that happens.

So, a damaged case could cause the leak, as could a damaged yoke, as could wear and tear from the torn crossmember bushing

Sent from my SM-N910V using Tapatalk

 

[H3-Me]

Thank you Alrock !!
Thats what I was thinking. Unusual movement in the differential housing. Much to my surprise, the 2 dealerships that have worked on this H3 have yet to mention a worn-out diff. bushing...??? I have an extended warranty but not sure if the bushings are covered yet. I will check on it tomorrow tho. I'm just driving on pavement with a few bumps here and there, but I'm sure there is still some movement even just driving highways and streets. I asked about a wear ring on the yoke where the seal rides, and the service advisor looked at me like I was stupid...??? I knew I asked the wrong person. I will also check with the tech performing the work about the wear ring/groove on the yoke. Thanks again Alrock !!

 

[woodwardsh3]

The seal can wear a grove in the shaft over time, and the new seal will not be able to seal it any longer. Did they inspect the shaft for grooves? If it has grooves, They some times have a steel sleeve that will fit over the shaft to repair the sealing area on the shaft. They have them for harmonic balancers I think they they call them Speedy sleeve's
hopes this helps.

 

[H3-Me]

Thank you woodwardsh3 !
Alrock mentioned the wear ring/groove on his post so I need to check and see. It doesn't appear to be coming from the seal to shaft. It looks like its coming from around where the seal sets in the housing..?? I think the first order will be to get a new/rebuilt cross member or bushings and secure the housing from moving.
Thanks again !!

 

[4speedfunk]

H3 yokes (both front and rear) use replaceable sleeves on them. No need to replace the entire yoke. The pinion seal kit below comes with both parts of the two-piece pinion seal. If your yoke is grooved...you'll have to cut the old sleeve off, and press the new one on. The sleeve is very difficult to find by itself but, a GM dealer should be able to get it for you. I usually get them in the pinion seal kit listed below. If you don't want to screw with it...you can replace the entire yoke which comes with the sleeve already on it (like alrock used).

Most likely the seal keeps failing because the pinion bearing is toast. Without proper preload...the pinion will rattle around in the housing, making it impossible to seal up. Replacing the seal-only is a bad idea anyway, as disturbing the crush sleeve will render it useless for maintaining bearing preload after you re-tighten the nut. Technically the crush sleeve should be replaced along with the seal....then re-torque the pinion nut (with a new crush sleeve) to restore the proper preload to the bearings (15 in-lbs). This requires you to remove the carrier to access the crush sleeve....which is very time consuming. Then it also requires you to crush the new sleeve which normally requires two people, a huge pipe wrench, and a 4-foot long cheater bar.

Doing the quicky "seal-only" fix takes five minutes. Sometimes it works. Sometimes not. I'm guessing in your case...it didn't work. I would highly recommend new pinion bearings & races, crush sleeve, pinion nut, and seal. Nearly every H3 front axle I work on, needs these parts. The AAM-7.6 is such a POS that AAM sells several pre-packed kits for a multitude of problems. So depending on what you find after you tear it apart...you probably need one or the other of these kits. Most likely the second kit, and you should buy new pinion bearings & races separately. Ninety percent of the time, the pinion bearings are smoked. Carrier bearings rarely need replaced as they only see 4.56-th of the wear & tear.

Master bearing kit here (comes with pinion & carrier bearings, crush sleeve, nut & washer...but no seals)...
http://www.demandaam.com/product-catalog/installation-parts-and-kits/master-bearing-kits

Pinion seal kit here (comes with the pinion seal and yoke sleeve. Also comes with new crush sleeve and nut...but no bearings)...
http://www.fortwayneclutch.com/inde...le-pinion-end-yoke-seal-kit-sku-74020004.html

Although stock crossmember bushings totally suck...I doubt if it has any effect on the seal.

 

[H3-Me]

Thank you 4speedfunk. I TOTALLY AGREE!! However, after talking to the GM dealer today(3rd person to touch the seal), they have informed me that the first shop that tried to "Quickly Seal" replacement method as you described, "GOUGED" the inside of the housing(in 2 places 1/4" apart) where the seal sets inside the housing allowing the gear oil to run out. Needless to say, I will be paying a visit to the first person who replaced the seal, which was also the Second person to try and seal the leak. I did not question if a new crush sleeve was installed because these were BOTH Large reputable Car Dealers in my town. Wont make that mistake again.!! This is my first experience with a Hummer H3, I know every vehicle has its quirks, but this is not a good start for me. Thank you again for the information & the links. She will get a housing, New bearing set, crush sleeve, seal and bushings for the side and cross member.