While on a cross country trip the rear end exploded while towing out fifth wheel. I thought it was a blow out. I looked in the rearview mirror and saw smoke poring out of the backend of the truck. By the time I got it stopped the axels were froze.
The truck was towed to Frankin Chevrolet in Statesboro Ga. The service manager showed me the bottom of the rear end it was opened up like a beer can. The new rear end was installed a week later after being shipped from New York. All was covered under warranty.

All in all everything worked out great. We are back home with no more problems. The service manager Alan got me out as fast as possible. I wish I had this dealer close by.

Mike

How much were you towing and what kind of gear oil did you put in it? Scary. . . .

How many miles were on it?

The truck had 32,000 when it happened, now it has 36,000.

I changed the fluid and put the G M grape juice in at a 1,000 miles. The fifth wheel weighs about 12,000 loaded.

Mike

Wow, very sorry to hear about your issues. Hope everything works out for you and they find out why that happened... Would not want that to happen again...

I am sorry. I forgot to put in my orginal post the the driver's side axel seal went out, and bye bye went the oil.

Mike

It would seem that there may be a connection between filling the rear to the fill hole and axle seals failing. Many have said that from the factory it is down quite a ways from the hole. I know mine is. Perhaps filling all the way is a problem. It would be an interesting poll.

The service manager was very explict. Do not fill within 15 mm of the fill hole. I cannot remember where my level was.

Mike

In my owner's manual it specifically states that it is within spec to fill to 0 mm below the fill hole.

I don't think it's all that critical if you fill below or to the hole. Think about it. How many dealerships doing these gear oil changes do them to spec or even read a manual for an oil change. And how many stories do you hear of service people not knowing much about these trucks. Yet you don't hear about a lot of issues with the rears.

I think the seal simply went first, not because anything done concerniing filling, then unfortunately on a long trip most don't check for seal leaks.

In my owner's manual it specifically states that it is within spec to fill to 0 mm below the fill hole.Eric posted before that the later model owners manuals had the 15mm or so lower level and the earlier guys had the fill to top.
Can't remember the year break that this happened.

I do not think the seal was leaking that long. When the rear end blew the whole front of the fifth wheel was covered in gear oil. That night the inside of the trailer smelled like burnt grape juice. If it had been leaking I would have seen it on the trailer.

When I picked up the truck I bought 4 qts. of the grape juice to change on the way home. I tried to check the level of the rear end when I picked it up. I could not touch the oil with my finger. I put 3/4 of a qt. in before I could feel the level. I took it back the next day and they checked it. I do not know if they put any in.

I think something else happened that caused this rearend to fail.

While complete failure can and will occur if there is no gear lube I do not believe a leaking wheel seal caused your failure. Since I cannot see the gearset and bearings first hand I am just guessing. It would take quite a while for a leaking wheel seal to leak enough gear lube to cause damage. In addition, I am uncertain it is possible for a wheel seal to leak the housing dry. The fact that your camper was covered in lube after the failure further proves that the diff was semi-full of lube when it windowed the cover.

I would bet this gear set was set up wrong from the factory and/or there was a bad bearing from the factory. The fact that you were working the rearend hard only accelerated the failure.

Just my two cents............................

And you had better not be the real Michael Moore:D

I am thinking about changing my name.):h

I wish I knew what happened. I was scared to death all the way home. Everytime I would hear a strange noise I would freak out. When It blew It opened the bottom of the rearend housing like a beer can.

Mike

Pictures would tell the story, Wish you had some to share.

The fact that there was no warning would point to a single component failure. Anything from ring gear cracking to a pinion failure. Can't tell without the pics.