Anyways, I'll try to describe this as best I can. I've had 4.77 w/le607 installed for about 6 months and everything seemed fine. The other day I was about 30 seconds from my warehouse and I heard a noise from the rear. It was kind of a clicking/repetative thunk as I was decelerating/coasting. Kind of like when I was a kid I would put cards in the spokes of my bike, the faster I would go, the faster the noise was. However the noise is only when the car is in neutral/coasting, not while accelerating.

So, I got under the car and noticed some fluid on the diff drainbolt. When I undid the filler bolt some fluid poured out so there was enough fluid in there. When I undid the drain bolt, bad news. Looked like metal chunks about the size of a pencil eraser and lots of metal shavings. I cleaned off the drain bolt and it is tore up. Part of the magnent is missing and the bolt has big chunks taken out of the middle and a big chunk taken out from one side of the bolt to the other through the threads. I can try and post a pic of the bolt and bits later if that helps.

So question of the day is, any thought as to what might have happened? I did a search, but only found diffs that completely blew up or had whining. Sorry for such a long post, but I'm trying to be thorough.

 

Forgot to add, no clutch dumps have been done.

 

I have seen many that have combusted. I cryogenically thermal cycle all of them now. The housing and caps are cast crap. Even the Comptech won't help a lot of rearends I have seen. Comptech reinforecment helps but Cryo-treating is the best solution to the problem. Good luck. PM me if you need any help.

 

Doesn't really explain why his exploded though. How long has the 4.77 been in there? How many miles?

 

I've had the gears for about 6 months. I got them from a friend who was supercharged, but he only had them on for about 1000 miles. The fluid still looked good when I drained it.

 

Well, 134K miles with no problems then 6 months of 4.77 and it explodes? I'd be thinking it was some flaw in the gears or the install.

 

Something damaged the magnet and a bit of (very hard) magnet damaged even more.
IMO if the caps fail you just hear a big bang.
Same goes for the bolts.
You were able to drive so I'm thinking missing teeth on the set.
The ring gear rotates right above the drain / magnet plug.
You can inspect the ring gear with a flashlight lying under the car with the drain plug out.

Are you going to take the diff apart?
Post pics please.

Sorry to hear this.

 

Just curious what kind of scientific evidence you have of this?

 

I'm going to pull the diff this weekend and take it down to a highly recommended shop next week. I'll try to get the old parts back and snap some pics for you guys. Call me crazy but it looks like one of the gears swiped the drainbolt as there is a gouge side to side through the bolt.

 

Out of curiosity, who was the 4.77 manufactured by?