1998 V70R AWD Angle Gear cooks the oil

Post by **jimmy57** » 16 Jun 2012, 09:57

The viscous coupling can be the cause.
With car in Park or if manual transmission, in reverse with front wheels chocked securely behind wheels, remove the lifted wheel and put a breaker bar with correct socket on the axle nut. The lifted rotor/hub should be able to be turned with a force of around 120 N-m and should move smoothly. You may find it takes considerably more force to move the rotor/hub and it will move in increments when you increase the force, not smoothly. You may also find that the force you will need to apply excceds the amount it takes to turn the nut on axle and the rotor/hub has not moved any more than the yield of the differential mount bushings. The last two instances indicate a faulty viscous coupling.

There are two different gear ratios for angle gears so there could be another explanation. The ratio of the one for your 1st generation XC70 is 1 :3.31. The later versions use 1: 2.62. Are you sure you have the correct one for the 1st generation system? I have never had the wrong one installed but I would think that huge difference would make the car come to a stop by itself when you lift foot off throttle. There would be a HUGE difference between front and driving speeds and create a severe bind between the front and rear drives. I would expect the wrong one would have attempted to spin a tire on rear when you turned too.

gmtgmt · Post by **gmtgmt** » 16 Jun 2012, 11:02

jimmy57 wrote:The viscous coupling can be the cause.
With car in Park or if manual transmission, in reverse with front wheels chocked securely behind wheels, remove the lifted wheel and put a breaker bar with correct socket on the axle nut. The lifted rotor/hub should be able to be turned with a force of around 120 N-m and should move smoothly. You may find it takes considerably more force to move the rotor/hub and it will move in increments when you increase the force, not smoothly. You may also find that the force you will need to apply excceds the amount it takes to turn the nut on axle and the rotor/hub has not moved any more than the yield of the differential mount bushings. The last two instances indicate a faulty viscous coupling..

Not getting this part
front wheels chocked securely behind wheels, remove the lifted wheel
Should i raise one wheel at the time and let the other 3 be on the ground and is the front or rear wheels?

When i put it on jack stands on the front only (rear stil on the ground) and put it in park i can toqure the both front wheels lugs to 140N-M.

jimmy57 wrote:There are two different gear ratios for angle gears so there could be another explanation. The ratio of the one for your 1st generation XC70 is 1 :3.31. The later versions use 1: 2.62. Are you sure you have the correct one for the 1st generation system? I have never had the wrong one installed but I would think that huge difference would make the car come to a stop by itself when you lift foot off throttle. There would be a HUGE difference between front and driving speeds and create a severe bind between the front and rear drives. I would expect the wrong one would have attempted to spin a tire on rear when you turned too

This is the right gear for this model because i ordered it by the VIN and it changes in the parts number if the vin is higher its double checked

Today I removed the drive shaft and changed the oil to Mobil 75W90 and it runs great after 50miles drive no overheat or anything, no whineing sound so i think the gear is ok

so its somthing from the Driveshaft and back thats clear

Post by **jimmy57** » 16 Jun 2012, 11:35

Yes, I left out the part about taking off a rear wheel and others are on the ground. You are turning the VC through the rear wheel with the front drive locked. The purpose being to "feel" out the VC by use of the breaker bar on the rear axle nut.

I swear I had typed the raise rear wheel part..........multi-tasking does take its toll.

Since the fronts are directly locked by it being in park, torquing those is not a VC test. The front is direct linked to gearbox but the rear is an auxiliary drive with the VC between the prop shaft and the rear diff. VC is designed to yield for normal expected speed differences and firm up to drive rear wheels when the front slips and overspeeds the rear several percentage points more than ever happens in non-slip circumstances. VC is always firm enough to give some torque to rear so when the prop shaft is out you will find many more situations where the fronts lose traction when it never did before.

gmtgmt · Post by **gmtgmt** » 16 Jun 2012, 12:28

Thanks

So if i cant turn lets say left rear wheel at about 120nm with like a toqure wrench at when its raised alittle and others are solid on ground in "Park" its a bad VC?

I will have the AWD repaired i just removed the Prop shaft, so I can Preclude the Front wheels from faults and it vertify its the Rear Wheels its wrong with.

Post by **JDS60R** » 16 Jun 2012, 14:03

Great stuff guys !!!!
Please let us know if it turned out to be a bad viscous coupling and what the failure was.

I think the info on the 120Nm test will be great for anyone looking to buy the same generation AWD.

Jimmy - you are a very valuable resource!!! Thank you for taking the time to share what you know.

gmtgmt · Post by **gmtgmt** » 16 Jun 2012, 14:45

Yeah jimmy57 this has been very help full.

I will come with an update when i find the problem

Also found this if someone needs parts for rebuilding the Angle gear

http://www.brickboard.com/AWD/volvo/144 ... build.html

Post by **MoVolvos** » 17 Jun 2012, 02:11

gmtgmt wrote:
Today I removed the drive shaft and changed the oil to Mobil 75W90 and it runs great after 50miles drive no overheat or anything, no whineing sound so i think the gear is ok

so its somthing from the Driveshaft and back thats clear

I may not have read the entire Post carefully or correctly but I was wondering how much oil did you remove compared to how much you replaced? Should you have left the Driveshaft in to confirm it was not low or dirty fluid that cause the overheating

Blessings,
BKM
-

gmtgmt · Post by **gmtgmt** » 17 Jun 2012, 04:50

Again this was a Brand new Volvo unit that was mounted and they come with the correct oil and level allready.

stokerjoker · Post by **stokerjoker** » 17 Jun 2012, 10:54

Hello gmtgmt,

How are you making out?
It maybe a silly suggestion, but if the rear tires are showing signs of wear, try checking the alignment of the rear axial.
A quick check, two people and a tape measure. Center to center of your wheel hubs.

Can't hurt.

gmtgmt · Post by **gmtgmt** » 17 Jun 2012, 12:29

The Rear tires have normal wear,

1998 V70R AWD Angle Gear cooks the oil

Re: 1998 V70R AWD Angle Gear cooks the oil