'02 V70 XC: Rear diff gears vs Haldex pump vs. What's next?

[leapdragon]

Hi all,


So was turning into a parking lot '02 the other day and there was a clear, momentary grab / bind out of the rear right (it seemed to me). Stopped what I was doing and drove the car home (about 0.5 mi). I've now put another ~2 miles on it with ears open. There are what can best be described as muffled clunks/pops coming from the rear, likely right, at low speeds, when turning.

I thought at first it was rear right e-brake, but took that apart and it looks fine. Wheel bearings feel ok and so do CV axles. Suspension parts still look good.

HOWEVER, when I rotate the rear passenger's side wheel, the effect is inconsistent, i.e. for a couple rotations the driver's side wheel will turn and then if you keep turning, the prop shaft will start to turn instead, and if you keep turning some more, the prop shaft will stop and the opposing side wheel will start up again etc. This is wrong, no?

Also, there is a "notchy" feeling when turning the rear passenger's side wheel / hub in either direction. That seems bad. I've done an awful lot of work with these, but end of day I'm strictly a shapes and colors guy... So I'm turning to the forum to see if we can save me the time of just tearing things apart one by one.

My Googling suggests to me that this is either rear diff or Haldex pump/clutches, but of course reading forms is giving me everything from "has failed" to "needs fluid change" for both areas. And worse, if you told me I'm getting it all wrong and the problem is in some other place entirely I would believe you.

I was inclined to pull the Haldex fuse and see if that improves anything, but then I hate to take a risk on increasing any damage by driving it any further if that's not going to tell me anything anyway and it turns out there's no fuse on an '02, apparently I'd have to unplug the pump under the car. And I could get under there and do a fluid swap on the diff gears, but I'd hate to waste time and money doing that if what I should be doing is dropping the prop shaft and axles (because I have no intention of replacing an entire diff and/or Haldex parts right now if there's no point to replacing fluids, etc.)

Would appreciate any advice on how the rest of you would proceed to diagnose/narrow down. Or would you just throw your hands up, drop the prop shaft, drop the rear CVs, unplug the pump, and be done with it? (I am sort of tempted)

[leapdragon]

Hmm, just realizing that for an '02 is should be a viscous coupler at the rear, which explains the lack of a Haldex AWD fuse. But we're getting into territory that's beyond me a bit. Any advice accepted.

[abscate]

I think we have one differential failure logged on p80 and p2 cars on this entire forum, that was chaosrob 99 v70R build.

It’s probably a viscous coupler (VC) failure , and you can remove thst with hard tools from underneath and drive it as a fwd only.

P80s VC are junkyard only. I don’t know about p2 ?

[leapdragon]

I just realized this morning out of the blue—that drive shaft should not have spun, I think, when I was rotating the wheels in the rear. The car was not in neutral, the parking pawl was engaged and the rears were off the ground but the fronts were on the ground.

The fact that rotating a rear wheel shifted movement back and forth from opposite wheel to drive shaft—that means the collar sleeve is stripped, no? In which case, the rear diff and rear anything should sort of be immaterial, no? That is to say—if the drive shaft can turn while the front wheels are on the ground and the gearbox is in park, then the connection between the transmission and the rear isn't there anyway. Am I thinking about this right?

I could have sworn that the noises were coming from the right rear wheel area (near the rear diff)—but is it possible that the momentary shudder and the noises I'm hearing merely sound like they're coming from the right rear, but are actually the angle gear collar all this time giving way? Do people often hear that in the rear for some reason when it goes?

[scot850]

With the older AWD systems you can get issues in any area of the system with the age of the car.

Angle gear is one (collar stripped and/or the angle gear spline)

Prop-shaft front bearing and the center support bearing mount failing

Viscous couple unit - unit itself failing or the 'nose' bearing in the front of the VC housing failing. Also the front mount on the casing perishing.

Rear axle - diff failing or dry (are the axle or input seals leaking). Axle cv joints worn or the rear hub nut loose.

Neil.

[Blacklab467]

I just realized this morning out of the blue—that drive shaft should not have spun, I think, when I was rotating the wheels in the rear. The car was not in neutral, the parking pawl was engaged and the rears were off the ground but the fronts were on the ground.

The fact that rotating a rear wheel shifted movement back and forth from opposite wheel to drive shaft—that means the collar sleeve is stripped, no? In which case, the rear diff and rear anything should sort of be immaterial, no? That is to say—if the drive shaft can turn while the front wheels are on the ground and the gearbox is in park, then the connection between the transmission and the rear isn't there anyway. Am I thinking about this right?

I could have sworn that the noises were coming from the right rear wheel area (near the rear diff)—but is it possible that the momentary shudder and the noises I'm hearing merely sound like they're coming from the right rear, but are actually the angle gear collar all this time giving way? Do people often hear that in the rear for some reason when it goes?

Yes your AG or collar sleeve is trashed, the propshaft should not be able to turn independently of the transmission. They make a bit of noise but not for too long when they go. I’d take the angle gear and propshaft out and use it as FWD until you can source parts and see what you’ll need. It’ll take about a half day to remove these parts. Often the splines on the angle gear input go bad before the collar splines, necessitating a new angle gear unit ( or a serviceable used one). In any event, you can remove these parts and continue driving while you come up with a plan.

[leapdragon]

Okay, that's what I thought. I was so busy paying attention to the rear end the other day that the fact that the shaft was rotating didn't even strike me until much later.

Yeah, I've done CV axles and prop shaft on multiple cars so this doesn't feel much harder than that.

So here's a question—I am seeing parts out there for 2003+ collar sleeves. But I thought I also remembered reading somewhere that they're the same across all the P2 years. Is there legitimately a difference between the 2001-2002 model collar and the 2003+ model collar? (And if so, should I order the older one, i.e. if the spline count is different, or the newer one, if say the newer one is more durable?)

Further question: How hard is it to get the collar of the transmission? I've seen people say there's no point in trying, requires a special Volvo hydraulic tool, just convert to FWD and other people say that this is only a problem on manuals and that on automatics it just falls of... Suspecting the truth is somewhere in between?

[vtl]

Okay, that's what I thought. I was so busy paying attention to the rear end the other day that the fact that the shaft was rotating didn't even strike me until much later.

Yeah, I've done CV axles and prop shaft on multiple cars so this doesn't feel much harder than that.

So here's a question—I am seeing parts out there for 2003+ collar sleeves. But I thought I also remembered reading somewhere that they're the same across all the P2 years. Is there legitimately a difference between the 2001-2002 model collar and the 2003+ model collar? (And if so, should I order the older one, i.e. if the spline count is different, or the newer one, if say the newer one is more durable?)

Further question: How hard is it to get the collar of the transmission? I've seen people say there's no point in trying, requires a special Volvo hydraulic tool, just convert to FWD and other people say that this is only a problem on manuals and that on automatics it just falls of... Suspecting the truth is somewhere in between?

IIRC 01-02 vs 03-07 angle gear differ only at the flange. Everything else is similar enough. Don't quite remember at this point, but angle gear in 05 can be from 02 + my old flange.

While AG is out and the splines are good you may want to split it and reseal. They all leak eventually, except last two years of production.

Some people swear that the collar sleeve is a b**ch to remove. I used a cheap blind bearing puller from Amazon a few times on two different XC70s and every time it took no longer than one minute to knock it out. If yours is stuck I would highly recommend investing into inductive heater, which makes rusty bolts removal easy without breaking them. Heat the collar sleeve, it will expand and slide out without much effort.

Pressing a new collar sleeve can be done easily with two studs + drilled bar. Forgot the thread size, but Home Depot has it. Take one AG bolt with you. Lubricate splines going into transmission with ATF. Must use special grease on the splines going into angle gear: Volvo 31437986, Liqui Moly LM2003 or Krytox GPL 215. Last time I used Krytox GPL 206, which is highly thermally and chemically stable, and also sticks to everything as hell, but in this specific application high pressure resistance is important, so I'll be using 215 next time.

Don't forget to replace the seal in transmission. Transmission will loose some fluid, too.

[Blacklab467]

Okay, that's what I thought. I was so busy paying attention to the rear end the other day that the fact that the shaft was rotating didn't even strike me until much later.

Yeah, I've done CV axles and prop shaft on multiple cars so this doesn't feel much harder than that.

So here's a question—I am seeing parts out there for 2003+ collar sleeves. But I thought I also remembered reading somewhere that they're the same across all the P2 years. Is there legitimately a difference between the 2001-2002 model collar and the 2003+ model collar? (And if so, should I order the older one, i.e. if the spline count is different, or the newer one, if say the newer one is more durable?)

Further question: How hard is it to get the collar of the transmission? I've seen people say there's no point in trying, requires a special Volvo hydraulic tool, just convert to FWD and other people say that this is only a problem on manuals and that on automatics it just falls of... Suspecting the truth is somewhere in between?

The Angle Gear casting is slightly different on the pre '03 models but the parts are all the same inside, as vdi says, the flange length is different so you'll have to swap this part, the spline count is the same as is the collar sleeve. I've included a link that shows my method of removing the collar sleeve as well, no special tools required.

viewtopic.php?p=669135&hilit=angle+gear#p669135

[Blacklab467]

Here's a link to a post that I did 5 years ago that shows the method to removing the collar sleeve:

viewtopic.php?t=95073