Hard to tell but it kinda looks like a 3 to 2 shift.

 

If you have a lot of slop between the ring gear and the pinion, it puts a lot of strain on the gears, and exerts a lot of force on the bearings. In none of the cars I have ever seen this happen to was this ever a case of '' It just happened''. If a roller pops out of a bearing, or a chip pops off a gear, then yes, whammo. But it didn't just happen today.

 

I'll dig into the case but I doubt I'll find the reason or what had failed.

 

My '88 944 NA trans spit its Ring & Pinion while just tooling around town, so they go when they go...

FWIW - I bought a rebuilt unit from Ian at 944online.com. Shipped it and returned the core via UPS (not a happy UPS driver, that one).

 

Update- For the first time since the event, my car was moving under it's own power. Had most of the transmission installed since last fall, just never got around to getting it buttoned up until this month.

Now there's a clicking from the rear when the clutch is released. The feller that sold me the new (used) gearbox said it was OK. I may have left the coupler untorqued but could I have a crapped torque tube?

My next step is to uncouple the transmission and see if it goes away... if not the only think spinning back there is the TT.

At the least, I can get $3000 trade in on a KIA.