Rear Differential Gears: Cracked in Pieces! WHY?

[Mike Schmitt]

In December 2011 I had a new rear differential cover put on due to a small leak. At that time the gears were in fine condition. Over the course of the next 9 months the vehicle was driven on a limited basis, perhaps 20 miles per week. Then we started to hear noises from the rear. A mechanic (not the one that put a new cover on) discovered that everything in the rear diff was cracked and shattered. The worst he'd ever seen. There was very little gear oil in the rear diff, BUT NO SIGNS OF A LEAK. My assumption of course is that the first mechanic failed to put the right amount of gear oil when he replaced the cover. But my question is: how certain can I be of this? Is there any other possible explanation? What else could possibly cause such a drastic cracking of the gears?

 

[Molson02536]

In December 2011 I had a new rear differential cover put on due to a small leak. At that time the gears were in fine condition. Over the course of the next 9 months the vehicle was driven on a limited basis, perhaps 20 miles per week. Then we started to hear noises from the rear. A mechanic (not the one that put a new cover on) discovered that everything in the rear diff was cracked and shattered. The worst he'd ever seen. There was very little gear oil in the rear diff, BUT NO SIGNS OF A LEAK. My assumption of course is that the first mechanic failed to put the right amount of gear oil when he replaced the cover. But my question is: how certain can I be of this? Is there any other possible explanation? What else could possibly cause such a drastic cracking of the gears?

Being a 2011, you have a G-lock rear end, they are know to explode when abused from rear wheel spin and the locker activates.

http://www.youtube.com/watch?v=N8iuLkSh0C0
http://www.youtube.com/watch?v=6Zit49L-7_A&NR=1&feature=endscreen

Hope this helps.

Molson02536

 

[GMC Customer Service]

Mike Schmitt,
Was the repair work you mentioned from December 2011 performed with your GM dealership or elsewhere? We're available to check into things with any of our dealerships if you like. Don't hesitate to send us a private message with more information (including the last 8 digits of your VIN and mileage) if you have any questions.
Sarah (Assisting Stacy), GMC Customer Service

 

[Mike Schmitt]

Well actually it is a 1994 Suburban and the work was done on it in 2011. I don't know what a G-Lock rear end is, but would a 94 have it?

 

[Mike Schmitt]

Mike Schmitt,
Was the repair work you mentioned from December 2011 performed with your GM dealership or elsewhere? We're available to check into things with any of our dealerships if you like. Don't hesitate to send us a private message with more information (including the last 8 digits of your VIN and mileage) if you have any questions.
Sarah (Assisting Stacy), GMC Customer Service

Thanks for responding Sarah. No, the work was not done at a dealership but rather at a private shop. I would be interested in getting the opinion of experienced GMC mechanics if you could somehow put me in touch with any.

 

[GMC Customer Service]

Thanks for responding Sarah. No, the work was not done at a dealership but rather at a private shop. I would be interested in getting the opinion of experienced GMC mechanics if you could somehow put me in touch with any.

Hi Mike, if your vehicle is a 1994 model, the only advice we can offer would be to contact your local GMC dealer as it is out of our range of available information.

In terms of putting you in contact with anyone, their service techs at your local dealership are in the best place to help you with any inquiries you may have.

Thank you,
Sara L (Assisting Stacy/Sarah)
GMC Customer Service