So, more woe to come on the prequel later, but for now I think I may have very quickly, very permanently, and probably rather expensively just converted my AWD Volvo to FWD.....Read on..
Car in question, 2015.5 V60 T6 R-design with Polestar flash, just turned 100K miles. Up north we've beet storing our old camper in the barn. We just went up for the weekend, four of us in the main house, with our eldest, SO, and kids in the camper. Well they got up first and set the camper up for the kids. We get there late. Next day, they hadn't managed to put out the slide out's etc. properly as we'd just dropped it in there in a corner, not thinking it would be an issue. So we partially collapse and go to move it a couple of feet forward and over.
So I hook up the Volvo, jump in, release the parking brake (I thought.....) and went to move it. No joy. I get out, check for chocks and things. Still no joy. Now this is where I majorly berkeley up. I ASSUME the brakes on the camper have frozen as it's a dirt floor with high water table. SO I get in and rock forwards backwards harder and harder until... BANG..... spinning front tires?!?!?!? Oh E36 M3. The park brake never disengaged and I've just broken something.
So I now have a FWD Volvo, one assumes it's a) the transfer case in the trans, b) Doubtful, but Could have sheared something in the driveshaft. c) I've destroyed the Haldex or whichever rear drive unit it is. So, those that know these things, what's most likely, and how bad am I about to take it without lube?
If you have broken something in the AWD with what you described, it was very, very close to broken before.
My experience, which is quite broad, is with older ones, but the system is substantially similar, so...
Once we get to Haldex era, in order of frequency:
#1 failure is the pump in the diff. Thats not going to give you a bang when it fails. Secondary failure is the pump shorting and murdering the diff control module, or it getting moisture into it. Neither one likely to bang.
Splines on drive sleeve to transfer case strip. That could give you a bang, but will also give you a bit of a ratchet-ey noise when you are loading it as the splines jump. Easy diagnosis there is to lift the car, and see if you can turn the drive shaft. Hint: you should not be able to turn it.
Oil pressure/temp sensor in the diff fails. Again, no noises.
Pinion bearings get noisy in the diff sometimes, but that doesn't bother the AWD.
Internal failure of transfer case or diff is exceedingly rare, once you get past the viscous clutch units from the early days. Driveshafts can have ujoint nad center bearing troubles like any other car, but I'd thing you'd have noticed some vibrations.
Could you have a boogered CV joint in the rear axle? I've never seen it, but it's a possibility, I suppose. It was jammed up and you took it apart when you moved it? Not super likely.
Bang FWD usually means the collar/angle gear interface stripped. This is not peculiar to Volvos, anything with a splines connection open to the elements will get rust in the splines, which is jeweler's rouge, and it slowly grinds away at the splines until there is not enough metal left to transfer required torque.
I have seen it happen a lot on BMWs and Caddy CTS4s but never yet a Volvo, aside from forum people.
You will need a new drive collar and its attendant seals (inner and outer seals) and a new angle gear, as the splines on it are directly cut into the shaft that incorporates the ring gear, and it is serviced as an assembly.
Buckle up. I do not know for your car but the one for my P2R (with a unique angle gear) went from $1400 a couple years ago to nearly $2000. Perhaps Erie Vo-vo has a used one, they are good people to work with.
Edit: assuming you have the 3 liter, they have 50 in stock and pricing seems to be in the $175-275 range depending on condition/warranty. 0 in stock for the 2 liter.
This is why I love this place. Thanks for the input chaps. So one important bit of information that I didn't give you, as I didn't realize it was pertinent until your posts. So, for the last couple of months there's been a bit of a bearing type noise. Twice I've put it up on the hoist and gone around rocking wheel bearings, CV joints etc. looking for something worn, but I couldn't find it. Now with the clunk and instant FWD and both your comments about take off unit and I'm thinking maybe I didn't do all the damage, just finish off. We came down state early for a number of reasons, but at least I've brought it into work so I'll throw it up on the hoist at lunch time for a look see and investigation. Look for updates in a few hours.
Hmm. Hopefully not too bad news after all.
Well, that is certainly unexpected.
I will remember this when people start pooh-poohing Haldex. 
. It can transfer enough torque to break the driveshaft...
That's a new one for me. Sadly, Volvo drive shafts are not cheap, either. Used should be available, though.
At least the troubleshooting was pretty easy.
Once you get it off, I'm curious whether it's a bad weld, or a spot that hid moisture and rusted off. I can't imagine it just broke...
That was unexpected but easier than the sleeeve in the haldex angle gear.
I'm getting a refurbished one from Detroit Axle. I'm not swapping it, I've found a guy in Tecumseh who works from his barn for half the hourly rate of the local shops. I dropped it on him last night. I was supposed to be up North all week, but I had a new guy start in the office yesterday, so I came down state for that and heading back north at Lunch time. Will be back late Sunday, before leaving for a week long family trip out East so I don't have time.
I'll report back once finished and I can look at the old one.
I bet the CV joint was getting stiff and introduced the shaft failure.
The gift that keeps on giving. Got sent this photo late last week from the guy who's working on it while I was out of town. So, the rear diff mount snapped as well. Searching for a used one, first place that said they had one failed to come through. Oh well, it's only money, on top of the hemorrhaging with the Boxster, life isn't quite going my way right now.
That is some serious point loading to snap 2 parts like that, yikes!
Yeah that's an impressively strong parking brake, a modern electric unit I'm guessing?
GameboyRMH said:
Yeah that's an impressively strong parking brake, a modern electric unit I'm guessing?
No kidding!
Sorry, Ade. The car gods are not smiling on you right now.
TIG weld to fix it instead?
In reply to Tom_Spangler (Forum Supporter) :
I guess I forgot to sacrifice a kitten to automotive gods or something.
Gearheadotaku (Forum Supporter) said:
TIG weld to fix it instead?
Can't be done in situte, by the time it's out I may as well have a used one fitted rather than take it off to get welded and hope it's not distorted and is a good enough weld to hold up against a 99.99999th percintial user.
grover
Dork
7/12/22 11:45 p.m.
That's an impressive failure.
