I saw something here in this thread that should definitely be corrected.
The larger tires MUST GO ON THE FRONT AXLE, not the rear. Owners manual and TSB states that if you cannot replace all four tires put the "one or two" new tires on the front.
Rotation to keep the tires within 1/16 to max 1/8 of an inch of wear is recommended - every 5K miles or so b/c the front tires wear quicker.
Normally something like 90% of the power goes to the front wheels in this system.
If the front tires are smaller, they rotate faster which the viscous clutch "interprets" as front wheel spin, increasing the power delivered to the rear wheels.
For some reason the continual over-delivery of power to the rear on dry surfaces cooks the transfer case.
I bought a '98 V70 XC in October and went through a bunch of research about this tire thing. I needed to match two tires that had about 5000 miles on them. Discount Tire has a policy of installing new tires on the rear axle only. I sent them this TSB.
As the omnipresent Klaus said elsewhere (I believe) it may be a good idea to carry a can or two of fix a flat and a compressor in the spare tire area. And or join AAA. Flatbed towing only unless you disconnect the drive shaft!!
This is something I pulled from another post here:
Volvo TSB 4460005 calls out some of the issues with the older
AWD system (new models, S60 and 2003+ use Haldax AWD which
is different).
If you can live with them and know the previous owner followed
the guidelines then the AWD might be OK for you. Here is some of
the info from the TSB (the rest goes on to explain how
to service and inspect the AWD components and includes images so
I did not cuta nd paste it):
Wheels/Tires - AWD Information & Function Test
850 1997/S70/V70/V70 XC 1998-2000/V70 XC 2001-
1997-
Section
4
Group
46
No.
0005
Year
01
Month
01
Vehicles involved:
AWD/XC
AWD Wheels/Tires, Information and function test
Background
This service bulletin contains information to ensure that the all-wheel drive (AWD) system is not damaged when servicing wheels and tires. It also contains information about checking the freewheel and viscous coupling for the all-wheel drive (AWD) system.
Wheels and Tires, Information and function test
Information about wheels and tires and function test
Note! To prevent deterioration in the function of the power transmission system on All-wheel drive (AWD) cars, it is important to follow the instructions below.
1
All Wheel Drive vehicles have special requirements for tires and wheels. It is very important that the tire replacement guidelines below are followed. Failure to do so can result in damage to the AWD components (angle gear, viscous coupling/freewheel unit).
Always drive on tires of identical brand, size, construction (radial), tread pattern, load-, speed-, traction-, temperature-, and treadwear rating.
Never drive on mixed tires, except for brief periods when the temporary spare tire is in use.
Always use properly inflated tires of correct dimensions. Tire size and inflation pressures are shown on the tire pressure label located inside the fuel filler door.
Caution! Failure to always drive on properly inflated, identical tires of correct dimensions may result in a circumference difference between tires on the front and rear axles. This will cause excessive tire wear and may damage the transmission and all wheel drive system.
2
Replacing the tires
When tire replacement is necessary, Volvo strongly recommends replacing all four tires at the same time with identical tires as explained above. Failure to do so can result in circumference differences that may damage the transmission and all wheel drive system.
If only one or two tires are replaced, the new tire(s) must be identical to the tires with which the car was built, and must be mounted on the FRONT AXLE ONLY! Failure to do this may damage the transmission and all wheel drive system.
3
Spare wheel Temporary spare
The temporary spare tire is for temporary, low-speed, short-distance use only Do not drive on the temporary spare at speeds above 50 mph (80km/h) or for distances greater than 50 miles (80 km) or transmission and all wheel drive system damage may result.
4
Snow chains all-wheel drive (AWD)
On all-wheel drive cars, (AWD), snow chains must only be mounted on the front wheels. Only snow chains intended for all-wheel drive (AWD) cars can be used. Never install snow chains on a temporary spare tire.
|