Hi Folks,

Can I lift the rear end of my 2000 v70xc by placing a floor jack
under the center section of the rear suspension ?
The point where all of the inner control arms mount to ?
I already have the front end up and the "K" frame sitting on jack stands.
I want to "convert" to front wheel drive by removing the drive shaft.
I'm 95% sure that the "bevel" gear has taken a dump.

Thanks in advance!
John

Yes, you can, but why whould you need all 4 wheels off the ground? All you need are jack stands just in front of the rear wheels.

Before you remove the prop shaft, grab a file and make a mark on the U joints and paint them. That way, if you ever put the shaft back on it will be oriented the proper way. Save the 16 bolts.

Is the bevel gear case leaking? What makes you think it is the bevel gear Vs the bearing in the Viscous coupling? Does it make noise while driving in a straight line?

Klaus

Klaus,

Thanks for the reply.

I just bought the car for my daughter at the local public car auction.
When I got the title I found out that the local "Not-for-profit outfit"
that takes donated automobiles and refurbishes them for low income families "dumped" the car at the auction as "too expensive to repair". When I called them they told me that bad "power take off" was at the top of the list. I did not speak to the technician that did the diagnosis, I spoke to a clerk that just read the diagnosis from their log.

The car makes a heavy klunk/bang when decelerating. I don't think that it makes a difference straight or turning. It suppose that it could be the VC locking up the front axle to the rear making the banging sound. Now you are going to make let the car down off the stands and drive it again. Will cold vs warm make a difference with the VC?

I just figured that, given my luck, it will be the most expensive part.

While I was under there surveying the damage, I did note that the Viscus Connector appears to be leaking. If it is the VC will that still make the noise
with the drive shaft out ?

Yet another question. I assume that there are splines between the front and back halves of the prop shaft. Will it separate or do I have to remove the intermediate bearing too ?

2 Reason for all 4 wheels up.
I like lots of room to work, especially if I have to snake the prop shaft out from between the Cat. Converter and the floor boards.
I can rotate the shaft to get to all of the hex head cap screws attaching the joints.

Which bears another question,
The center is definitely U-joint, are they actually U-joints at the BG and VC or are they more like CV joints ?

Thanks in advance for the help,
John

The 'clunk' you get is probably just the forward CV on the propshaft, made worse by a loose bevel gear. Check for any play in the front CV and make sure the boot is not torn. Also check for play in the center carrier bearing, which is attached to the shaft and comes off with the shaft.

The VC should not be leaking. Mine has a bearing that is too tight and shudders at low speed and tight turns - once the fluid warms up. If you remove the shaft, the VC will not make anymore noise. Junkyards can have pretty good replacements - up to 2000 or 2002?

Same for bevel gears, if they show signs of leaking they have probably overheated and cooked their innards - junk yard.

So, the forward joint is called a CV, the others are U joints. CVs have boots, U joints do not.

Also check out: http://www.v70xc.com/

good folks.

Klaus

It's official, we are FWD now. All clunking has stopped. On my test drive last night, all senses were heightened. I thought that I heard the Bevel Gear output shaft turning. Is that possible ?

Thank you Klaus for your able assistance.

Now it's decision time, "to repair or not to repair".
Can I find affordable replacements ?

How does one diagnose / discern the quality of Bevel Gears and Viscous Couplers when purchasing from a "you Pull it" junkyard ? Any advice would be greatly appreciated.

The VC should be fine pretty much no matter where you get it from. There seems to be a common theme in the forums that as they get old they have a tendency to act differently, but it's not altogether awful. It sounds like the fluid cooks up a bit and starts to transfer power front-to-back at a slightly higher than originally engineered rate - you'll have maybe ~8% full time AWD rather than the originally intended ~%5 say.

I have never read one report of the VC totally failing, though I am sure this is possible. I wouldn't worry too much about a used VC, but then again I wouldn't be too worried about your current VC either - it's probably fine, though old.

The most commonly reported symptom of an old VC is a 'thumping' under the center of the car during sharp 'parking lot' turns after some straight line driving (like on the highway). I think the theory is that as the fluid gets older it's viscosity properties start to degrade, and it heats up too fast during straight line driving. So you go out for a quick run on the road, which heats the VC fluid up, which causes torque transfer. But then when you're doing 'parking lot' turns your front wheels are moving at a different speed than the rears, which when combined with a torque-transferring VC causes the typical 4x4 driveline binding putting stress on the center prop shaft. On some 4x4 trucks this causes a little wheel-hop during the same maneuvers. The thumping is the prop shaft moving around in the rubber mount just ahead of the center u-joint, and running into the limits of that soft bushing and probably contacting the steel bushing holder. That's my understanding anyway. It's not the end of the world.

I have had my bevel gear apart and rebuilt it (though I haven't yet been able to verify if it's been a successful rebuild - I'll post about it when I'm done) and I can tell you that in MY bevel gear everything was in pretty good shape. The o-ring seal around the crown ring was totally shot (hardened) and a couple of the other seals looked like they needed to be refreshed, but the gears themselves and the bearings were all in great shape.

Any trans shop should be able to do this kind of rebuild for you, but it will cost about as much as a used unit from Eerie Volvo does, and they guarantee theirs for life!

Any driveline place should be able to give you a new bearing or replace the u-joint or either the front or rear CV joints as well. They will even be able to balance the shaft for you before you put it back in.

If you're interested in fixing this and don't have the mechanical skills or time to research and acquire them, start finding your local 4x4 and transmission guys.
--
1998 V70 AWD->FWD Turbo 200k+

You will now experiance a slight torque steer at full throttle, that is normal. You will also get better MPG, also normal.

The bevel gear is still turning, but should be of no concern. You might want to check the oil level and add some if needed - use synthetic only.

If you go to a pick&pull and happen to find a 2000-2002, get the bevel gear 1st, then worry about the VC unit second. Chances are that the bevel gear will also be bad, but you could take the housing apart and figure out what is wrong and fix it? If the splines are shot, you lost the gamble. The VC units are usually in good shape.

Klaus