XC90 AWD Problems, RWD not working

[P cow]

Originally Posted by pdrvolvo

this fault can be caused by a faulty sensor.i only have two wheel drive at the moment but i have been under the car and with all wheels on the ground i cannot turn the prop shaft which as far as i know means that the mechanical parts (i.e.splined sleeve and angle gear) are all ok.its a simple test and can be done without jacking up the car.i have a wireing diagram of the DEM (differential electronic module ) which must have a lot to do with the AWD system.there may be more than one sensor involved but to date i havent gone any deeper into the case.at present i cant be bothered takeing it to the dealers as it drives perfectly well as they all do plus i dont take it off road anyway.

peter.

please note the first sign of the awd not working will be a message anti skid service required.the problem is once you turn the vehicle off and restart the message will not come on again,the first you will realise you have a problem is when you need it as i have just found out (stuck in the snow)I have just opened the dem up,it turns out the previous owner changed the oil pressure sender & put the concave washer back the wrong way,fitted waher correctly cleared codes from Ecu job done,apparently 90% of awd problems are related to the oil pressure senser hope this helps.

[shaunroche]

Out of interest, this spline shaft that fails and turns the car into just FWD, is it housed in the transfer box?

If so, fittting another working transfer housing would solve the problem wouldn't it?

Additionally, I intending using our XC90 to tow a rally car on a trailer...will the fact that the car has lapsed into FWD only cause problems for the drive shafts, or any other parts of the transmission or cooling system etc. or should it be ok?

I tried turning the rear propshaft whilst on the ground and it spun regardless of what gear it was in...I assume this means that the spline has gone?

[skn]

Originally Posted by shaunroche

Out of interest, this spline shaft that fails and turns the car into just FWD, is it housed in the transfer box?

If so, fittting another working transfer housing would solve the problem wouldn't it?

Additionally, I intending using our XC90 to tow a rally car on a trailer...will the fact that the car has lapsed into FWD only cause problems for the drive shafts, or any other parts of the transmission or cooling system etc. or should it be ok?

I tried turning the rear propshaft whilst on the ground and it spun regardless of what gear it was in...I assume this means that the spline has gone?

The splined shaft transmits drive from the gearbox to the transfer box and is housed / accessed by removal of the transfer box.

Fitting another working transfer box would only work if you replaced the defective sleeve also as this is what actually transmits drive.

If you can turn the prop whilst the front wheels are on the ground then the splined shaft is kaput.

No issues with towing other than a reduction in traction in adverse conditions.

[Ducklakeview]

Originally Posted by shaunroche

Out of interest, this spline shaft that fails and turns the car into just FWD, is it housed in the transfer box?

If so, fittting another working transfer housing would solve the problem wouldn't it?

Additionally, I intending using our XC90 to tow a rally car on a trailer...will the fact that the car has lapsed into FWD only cause problems for the drive shafts, or any other parts of the transmission or cooling system etc. or should it be ok?

I tried turning the rear propshaft whilst on the ground and it spun regardless of what gear it was in...I assume this means that the spline has gone?

Yes!

The splined sleeve that fails, is the link between the gearbox and the transfer box. It's a 3 or 4hr job and easily done if you are competent with the spanners, access to the top two retaining bolts is awkward, but doable..

I've had my transfer box off twice in 8 months, first time to change the splined sleeve, and then again to replace the transfer box when the output shaft bearing failed

Splined sleeve is available on it's own for around £110 or as a kit containing the oil seals and grease for £120 ish - Get the kit and replace the seals whilst you have access!

Mike

[Tannaton]

Originally Posted by shaunroche

Out of interest, this spline shaft that fails and turns the car into just FWD, is it housed in the transfer box?

If so, fittting another working transfer housing would solve the problem wouldn't it?

Additionally, I intending using our XC90 to tow a rally car on a trailer...will the fact that the car has lapsed into FWD only cause problems for the drive shafts, or any other parts of the transmission or cooling system etc. or should it be ok?

I tried turning the rear propshaft whilst on the ground and it spun regardless of what gear it was in...I assume this means that the spline has gone?

Yes it should be fine towing, no significant extra stress but you will be more prone to the front wheels spinning if you push too hard. Bear in mind the towing weight of the XC90 is a measly 2.2 ton not 3.5 ton like most other full size 4x4. You will be close to that if not over with a car/ trailer combination. That said the chances of you getting stopped for it are probably slim to zero.....

[RoyMacDonald]

Originally Posted by Tannaton

Yes it should be fine towing, no significant extra stress but you will be more prone to the front wheels spinning if you push too hard. Bear in mind the towing weight of the XC90 is a measly 2.2 ton not 3.5 ton like most other full size 4x4. You will be close to that if not over with a car/ trailer combination. That said the chances of you getting stopped for it are probably slim to zero.....

I think there are only about 12 cars that can tow more than the XC90. My 27ft caravan weighs 1749 Kg. Still spare capacity for the TV etc. I don't know of anything bigger that would be towed except by a specialist vehicle as there is a physical size limit as well defined by law and my caravan is close to it.

Just remember if you passed your driving licence after January 19, 2013, the maximum weight you will be able to tow with a category B licence is 750kg, provided the total weight of the car and what you want to tow does not exceed 3,500kg.

[owenfackrell]

I have also replaced the spline shleve and transfer box (or angle gear in Volvo speak). As Mike says it's not to bad if you are confident with tools. The original shleve is a tight fit on the gearbox and can be hard to get off. I used an angle grinder to cut a slot and then a crow bar to pull it free. I did need to brace myself agianst a wall for purchase. As I had to get the angle gear completely out to replace it I found it easier to remove the exhaust bracket and some other little bits to help with access.

[Tannaton]

Originally Posted by RoyMacDonald

I think there are only about 12 cars that can tow more than the XC90. My 27ft caravan weighs 1749 Kg. Still spare capacity for the TV etc. I don't know of anything bigger that would be towed except by a specialist vehicle as there is a physical size limit as well defined by law and my caravan is close to it.

Just remember if you passed your driving licence after January 19, 2013, the maximum weight you will be able to tow with a category B licence is 750kg, provided the total weight of the car and what you want to tow does not exceed 3,500kg.

Unfortunately the legislation around towing has got so complicated (both construction/use and driving licence eligibility) that I don't think 90%+ of people who tow recreationally (i.e. excluding professional drivers) and 90% of Policemen are fully conversant. I think 80% - 90% of the trailers I see at my local tip aren't legal as they don't have a secondary coupling.

I read somewhere (but can't recall where) that the maximum towing weight of a car is based on what it can do a hill start with on a specific gradient. Hence the D5 with the AW55 gearbox probably didn't do well on this test although I am sure the car is structurally fit to tow much more.

[RoyMacDonald]

Originally Posted by Tannaton

Unfortunately the legislation around towing has got so complicated (both construction/use and driving licence eligibility) that I don't think 90%+ of people who tow recreationally (i.e. excluding professional drivers) and 90% of Policemen are fully conversant. I think 80% - 90% of the trailers I see at my local tip aren't legal as they don't have a secondary coupling.

I read somewhere (but can't recall where) that the maximum towing weight of a car is based on what it can do a hill start with on a specific gradient. Hence the D5 with the AW55 gearbox probably didn't do well on this test although I am sure the car is structurally fit to tow much more.

Our Defender is rated for 3500Kg but it recently towed an 18 ton refuse lorry that had become stuck across both lanes of the A21 back into the depot. You wouldn't go down a motorway pulling that load though.

[shaunroche]

Thank you one and all fellas for the replies! Very much appreciated!

I'll not attempt changing the spline myself but would be willing to pay for parts and labour if it's thought to take about 4 hours!

It only takes one stuck bolt and I'm done for see!

I'm in Cheshire if there's someone anybody could recommend local ish who could do the job please?

I'm 46 so I think my license allows me to get in everyone's way with a trailer btw!

Cheers once again fellas!!