Hello all.

Currently own a 99 S70 turbo with the AWD feature and I am having a bit of an issue that my local Volvo shop is having a problem diagnosing. Car has 135k on it and it runs extremely well, but occasionally when you turn hard in either direction the drive line shutters like something is binding. Local Volvo shop has checked the transmission, transaxle, and rear differential and all look good. The previous owner replaced the driveshaft just before I got the car at 100k. (No doubt this is why they sold the car) Local shop does not see many AWD S70s so they are saying we should start replacing parts, but as you all know driveline parts are quite expensive and I would like to narrow the list before they start replacing stuff. Is it possible that the drive shaft torque tube is the culprit? If so can this be rebuilt or just replaced? Unit alone is over $1,100 and that is just where they want to start....

All suggestions welcome.

Thank you in advance

Oliver

62 122S
66 1800S
86 245DL
88 245DL
96 850 GLT
99 S70 GLT AWD

Over a million Volvo miles and still smiling.....

Thank you guys for the quick response. I haven't thought about the ball joints but that is a great suggestion. Your responses and my online research tend to suggest the logical culprit to be the VC, but knowing that I can continue to run it if everything else checks out is good to know. The tranny and rear differential both got flushed and had fluids replaced the last trip to the dealer. Seemed to help for a while and then the shudder came back. Mine seems to be acting like Klaus's and normally gets worse after it warms up or is coming off a long straight line drive. Has anyone ever just removed the rear drive shaft and run their AWD as a FWD?

Oliver

62 122S
66 1800S
86 245DL
88 245DL
96 850 GLT
99 S70 GLT AWD

Over a million Volvo miles and still smiling.....

many people have done this (turned their AWDs into FWDs) and you'll find their posts all over this forum and others. Basically just removed the driveline that connects the engine to the rear diff and you've got an FWD.

You said you changed the trans fluid and rear diff fluid?

You should also change the fluid in the 'bevel' gear, which is bolted to the pass side of the trans in behind the block. It's where the center driveshaft gets its power and it is known to need fluid changes. I think KlausC normally recommends ~50k mile interval?
Information about what fluid to use is here: http://www.brickboard.com/AWD/index.htm?id=1311206&show_all=1

There's advice on how to do this all over this board and others, but Bay13 has a good article about it:
http://volvospeed.com/Repair/AWD_bevelgear_diff_service.html

How did your Rear-diff fluid change go? I'm interested in doing this but never have found the fill hole, though I know it's supposed to be on the front (facing front of car) side of the diff, on the driver's side.... What gear oil did you use? There was a brief discussion about this earlier as well that perhaps you have something to contribute to?AWD Rear Diff Fluid Change?


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1998 V70 AWD Turbo 190k+

Good question, I will get the bevel gear fluid checked, but the dealership did the tranny and rear diff fluid replacement when I took the car in about the shutter. (Actually seems to have helped some) I will be glad to ask the tech what fluid they use in the rear diff as I have an appointment early next week for a door lock issue.

Oliver

62 122S
66 1800S
86 245DL
88 245DL
96 850 GLT
99 S70 GLT AWD

Over a million Volvo miles and still smiling.....

Unfortunately there is no specified service interval on the bevel gear fluid, though it DOES need to be replaced.

I believe there is an official Volvo TSB about how to install the drain as described on Bay 13.

You may have to explicitly ask a dealer to do this, as it would likely not be listed as something that was needed in any standard maintenance manual.
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1998 V70 AWD Turbo 190k+

Lots of people have removed the propeller shaft with out any harm, except for the torque steer at lower speeds. Better mpg and throttle response, too. But, you lose the AWD in the winter.
If you take it off, mark the bolts and the shaft so that the weighted bolts can go back when you want to reinstall. Coat everything with light oil, rust is not good.

Klaus
--
Common sense trumps a PhD

Great post Klaus. Marking the shafts and numbering the bolts is not something I would have thought of if I had just gone out and removed the drive shaft. Not sure I am at this stage yet, but good to know that it could be done.

Thank you

Oliver

62 122S
66 1800S
86 245DL
88 245DL
96 850 GLT
99 S70 GLT AWD

Over a million Volvo miles and still smiling.....

I agree with the other posters - check your ball joints, and possibly think about just replacing them anyway, as they could probably go for a refresh anyway.

But the general consensus is that the shudder is a sign of a worn viscous coupler, and is generally not terribly harmful - though it sounds pretty bad and I'm sure it's not really all that 'good' for the car either :)

You can not rebuild them. Not without some extreme expertise in this area anyway. I've been advised not to let anyone take mine apart by members on various boards/forums.

I did look into getting a replacement from erie-volvo, and they wanted ~$500 for a used one that they warranty for 1 year. Not a bad price actually if it's really bothering you. The labour on installing one of these would be a pretty significant cost if you're not doing it yourself.


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1998 V70 AWD Turbo 190k+

My 1998 V70 did the same thing. After running a straight line for a while, slowing to do a 90degree turn, the car would shudder. Concenses of the V70R board was that the viscous coupling was getting tired and I should get a used unit at a junk yard. 50K later it still did the same thing with the original unit still on the car. On hot parking lot pavement, it sounds like a locked differential.
In either case, it is not harming your car. You could flush the rear diff to eliminate it from the equasion, but I wouldn't worry about it.

Klaus
--
Common sense trumps a PhD

Check the ball joints on both control arms and the sway bar links. When mine started to shutter, that solved it