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XCHauler
03-06-2007, 07:56 PM
My 2001 XC with 90,000 miles appears to have some problems engaging the rear wheels when needed in slippery conditions. We recently received about 28 inches of snow last week in Wisconsin and I was fooling around trying to get my Volvo stuck in the snow to check the functions of the AWD system. I managed to get the vehicle stuck and tried to get the Volvo out of the snow bank but noticed that only the front wheels would engage and spin. Both front tires would turn at the same time and shoot up snow. I was able to verify this by watching snow being shot up by each tire as they spun in the snow and ice. It is also my understanding that the rear wheels are engaged when the transmission is put into reverse gear. (is this correct?). I tried to move the car in reverse to engaged the rear wheels but only the front wheels would spin. I had replaced the gear fluid in the rear differential and bevel gear last summer and the transmission has had all of the Volvo updates including the ETM recall software. Has anyone experienced this problem on their 2001 XC? I did manage to free the XC but is fun to challenge the weather elements with this vehicle!

I currently have Nokian i3 tires (235/60/16) on the XC and they are performing very well with good durability. These are outstanding tires for drivers who spend most of their time on the road and may be a better solution for most XC drivers instead of the Nokian WR‘s. They provide outstanding wet and dry grip, are very quiet, and handle corners extremely well. However they are only adequate in heavy snow and icy road conditions.

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JRL
03-06-2007, 08:18 PM
So is there a question here or are you honking Nokians?

Neil R
03-07-2007, 07:36 AM
My early model XC does the same.

I experienced this trying to pull a boat out of some mud at the bottom of a fairly slippery launch ramp. The boat went nowhere and the car just sat there with the front wheels (only) spinning. (Solution was to wait for the tide to come in a bit!)

Must admit this wasn't what I'd expected from an AWD car.

Explanations would be appreciated!

Neil

JRL
03-07-2007, 07:47 AM
Nevermind, edited out my reply sorry

John@CdnRockies
03-07-2007, 08:27 AM
I can't respond wrt '01's but my '04 model handles this with applomb. All 4 tires turn evenly (had a similar situation to Neil on a boat ramp). I also recall a test sponsored by Volvo using 05 XC models where they balanced 2 wheels in mid-air (passenger front and driver rear would be suspended over a hole). All four tires would stop spinning and assume the same rotation rate. That worked in both forward and reverse modes. It was pretty impressive, so I assume there may be something mechanically wrong with your '01 setup.

John

Jorge-789995
03-07-2007, 06:55 PM
It is also my understanding that the rear wheels are engaged when the transmission is put into reverse gear. (is this correct?)..



Yep, you are correct. I was also trying to test the limits of my 02 XC in that snow, but since I have WR's, it wasn't easy. I had a tough time finding a place that was not plowed AND had a significant incline. I was able to start and stop at will in a snowy Park-N-Ride. I had to back up into the side yard (uphill) to hook up my trailer. I opened the door while backing up and saw the back tires spinning and throwing snow, so they do engage in reverse.

skibo
03-08-2007, 09:06 AM
Of course, keep in mind that 01-02 had the viscous coupling and the 03+ have the Haldex gizmo. Fundementally different approaches - can't really compare performance directly.

wgriswold
03-08-2007, 11:29 AM
I once saw an 01-02 stuck in a driveway dip (a 4" dip) with ice and snow in the dip and the front tires on pretty good asphault. The rear tires spun and the front did not move at all. Pretty disappointing.

TrueBlue
03-08-2007, 12:25 PM
I did some research some years ago and proved to my satisfaction (but not to VCUK's....) that the Viscous Coupling doesn't work when the car is stationary.

I have no idea how effective it is on the move, or why it should not work. I can only assume that it needs some rotation at the output end for the system to engage.

I believe that the VC is essentially a tube with paddles on the input and output shafts with some very special "goo" in the middle to transfer the power.

My own view is that it is "broken as designed".

I dumped my 2002 model because of that.

The Haldex is a different kettle of fish and works well.

staffann
03-10-2007, 09:31 AM
The visco does work from standstill as well. One thing to remember is that in order to make a visco transfer the maximum torque, one has to spin the front wheels quite a bit. There is also a time/temperature factor - the visco works better when it becomes warm, and it does get warmer as you spin the front wheels a bit. A visco is not a very sofisticated solution...

That said it is of course also possible that the tested units are faulty.

doublecheese
03-10-2007, 05:01 PM
I have a 2001 V70XC too.

I tried it on sand and recently I tried it on snow and all wheels spin.

See this video I shot on January 1st 2007 on the beach and see all wheels spinning on my 2001 V70XC

http://www.youtube.com/watch?v=2Vq_MM2X3yE

BTW I'm on Nokian WR SUV's

staffann
03-11-2007, 03:43 AM
doublecheese: If that video is of a 2001 V70XC, it has an incorrect name as it states "Volvo XC70 AWD on sand" and not "Volvo V70XC AWD on sand". Since people are commenting on the Haldex system maybe you should clarify that this is an older car with a visco! Otherwise people may look at the reaction time in the video and use it to talk down on Volvos. That said, it doesn't look bad for a visco!

Braking that hard on sand was brave... ;-)

volvoshad
03-11-2007, 04:09 AM
I once saw an 01-02 stuck in a driveway dip (a 4" dip) with ice and snow in the dip and the front tires on pretty good asphault. The rear tires spun and the front did not move at all. Pretty disappointing.

I'm not sure how this is possible with the VC set up. If the front wheels are not spinning, then the bevel gear, which transfers power to the rear, would also not be turning. The bevel gear essentially is part of the right front drive axle. Because of the differential in the front transaxle, it would be possible for the left front wheel to be stationary, and the right front wheel and rear wheels to be spinning, however.

Phrog
03-11-2007, 07:02 AM
I had the opposite experience with my 2001: parked on a slant
(nose down) on an icy street, put it in reverse, tried to backup. The front tires spun yet the rears did nothing. Strange.

-Phrog

wgriswold
03-11-2007, 01:17 PM
I'm not sure how this is possible with the VC set up. If the front wheels are not spinning, then the bevel gear, which transfers power to the rear, would also not be turning. The bevel gear essentially is part of the right front drive axle. Because of the differential in the front transaxle, it would be possible for the left front wheel to be stationary, and the right front wheel and rear wheels to be spinning, however.


It was three or four years ago. I may be misremembering which set of tires were not spinning. It wouldn't be the first time my memory has failed me. What is absoutely clear is that one set (front or rear) was stuck and one set was spinning. It was really disapointing to see an AWD car stuck in what was essentially a flat driveway and made glad I had the Haldex system.