'02 E320 4matic headscratcher....any ideas?
 

So, I just picked up my car from having the CV boots replaced. The inner boot on both front ones was torn in the same place. The CVs had under 10k miles on them.... Both joints were OK and still full of grease, but obviously, there's an issue with the parts...
So, I pick it up after he's got the boots replaced and I make it 15 miles down the road and BANG, seatbelt auto tightens, no power to the wheels and the SOS system goes off. Scared the fuch out of me.
Get it towed back and up on a rack and here are my observations:
the front right CV has 'popped' out of the transmission side
the rear output driveshaft from the transmission is only half present and looks like you'd expect to see with the failure of a driveshaft on an overstressed 4x4 (ie, looks like my landy driveshaft did when I blew it up.)
Somewhere in the failure, one of the transmission cooler lines got nicked and spewed fluid everywhere.
We both suspect no real transmission damage right now as I got it pulled over and shut down very fast.

My mechanic thinks the shock of the driveshaft snapping caused the CV to pop out. There's just this nagging voice in the back of my head that wonders if the CV was improperly reinstalled and that somehow overstressed the rear drive shaft...

I would go with your hunch. Perhaps something bound up in the front and caused the driveshaft failure. And I hate to be the one to tell you but those seatbelts are very pricey.

The driveshafts are friggin pricey....almost 2k rebuilt from Mercedes....500 aftermarket rebuilt...the seatbelt is back to normal operation and he has a STAR module so he can reset the computer.

An edit: it is actually the front driveshaft....didn't realize that it came from the middle of the car towards the front....not like that on the landy.... so very directly tied to the CVs.....I'm not happy....he's got the aftermarket rebuilt one ordered and is going to fix the nicked line......I'll broach fault once the vehicle is running...but at this point, it's gonna be pretty hard to convince me that this isn't his fault...
I hope he just mans up about it, he's treated me very well in the past and often cuts me breaks on labor, I've probably spent $20k there between routine stuff for the Mercedes, the money pit Jaguar and my Landy...
It just seems like the most likely cause was that CV not being properly installed and binding up...

I still have yet to find anyone who has seen a drive shaft on one of these fail in this manner....It's insane..

I've heard no end of horror stories about Mercs built during the Chrysler merger years.

Ill tell you, it scared the he'll out of me....

This reminds me why I drive a very old car.

lol, I was just thinking the same thing about my Rover......stuff breaks all the time, but it's simple and straight forward to fix....

Similar happened to me.

Bolt left untightened at reassembly when the steering hub is moved away to access cv shaft.

Hmmmm, I might have to swing up there and take a look at the bolts on that assembly. Didn't think about it at the time, but it makes sense....

Got a call this afternoon that it's ready. I was out of town and told him I'd pick it up in the AM. I stopped by the shop on my way back in town (about 20 minutes ago) to take it for a spin with my spare key......the key I left with him was in the ignition....vehicle unlocked......not happy #1....Crank it over and the check engine light is on......not happy #2....seatbelts are locked.....not happy #3 (he told me not an issue)......take it for a spin and there's a high pitched whine from the front end the whole time.....not happy #4 (though, it did drive fine, but it drove fine until it went nuclear as well)......bring it back to the shop and get out.....something is burning....dunno what, but it smells like hell.....not happy #5.....

Dude - sorry to say this again, and I could be wrong, but I am under the belief that those seatbelts are a one-time-srs lifespan!

yeah, did some digging and it looks like that's correct.....along with a myriad of sensors that only cost a few grand each to replace.....
not happy......still can't find anything to convince me that this isn't his fault.....especially coupled with the knowledge that his assistant has a history of not tightening bolts (almost had a wheel fall off because he didn't tighten the lugs once....TEB took her car there once and he forgot to put the under tray back on...)

Twice I was hit from behind in my Ml430. Both times the SRS pretensioners went off (driver's side only). Quite startling - both the impact, and the price! Thankfully, insurance paid it.

All 4 pretensioners have been triggered....this should be an interesting one to explain to geico...

What is a TEB??

A person.... The Evil B (female dog)