Hi I removed the propshaft to see if the awful noise went and it has , very quiet in two wheel drive only The prop and joints seem ok so what I would like to know please , do the diffs give trouble or have I missed something ?? Any suggestions Many thanks
Firstly, have you checked the bearing in the centre of the prop? they can fail sometimes. Next, what is the noise like? Is it a knocking or a grinding? And which part of the car does it seem to be coming from (front/middle/rear)? Does it do it all the time or just when turning corners or travelling in a straight line?
Angle drive ?
hi just to update i had a good look at the front cv joint on the propshaft and found it was was in a right state !! so will find a replacement and refit prop and see if the noise has gone , I am not convince that all the noise is from the cv joint but it might be ! Do the short shafts the one that connects the diff to the prop ever give problems ?? as it looks a pain to remove but at the stage it might be better to have a good look before i refit thr prop cheers
The front CV joint does tend to suffer more as the heat from the exhaust and engine cooks it, I have re-greased mine a few times now just to keep it healthy(ish). As regards the short shaft, I'm guessing you mean the mechanical viscous coupling (presuming your car has the mechanical unit andnot the later electronic haldex unit). Most of the problems tend to be with the angle gear or the propshaft, not heard of many cases where the viscous coupling has caused a knocking, they can fail but internally.
Hi now i have found angle drive in shot , what sort of job is it like to do ? i have a ramp and and full range of hammers thx
Angle gear isn't too bad a job to do.
In its simplest - remove the offside driveshaft, undo the propshaft from the angle gear (fortunately you got that bit sorted :) ), you might have to undo the steering rack crash protection (large black plates around the steering joint on the rack), undo the angle gear bolts, separate it from the gearbox and rotate it so it can slip down through the gap between the engine subframe and the sump (its heavy). You might have to undo the steering rack pipes if they are routed under the middle of the engine as they get in the way (on later engines they routed them down the side of the engine subframe out the way).
Best case scenario (hopefully) you'll find the angle gear is ok and that the 'connecting sleeve' between the gearbox and the angle gear has worn the splines away. The connecting sleeve is usually difficult to remove from the gearbox (they threadlocked/glued the sleeve to the gearbox hence the difficulty to remove it), one way to remove it is to grind 3 notches into the sleeve and use bearing pullers to get it off. Connecting sleeves are about £90 from Volvo. Even if the angle gear is knackered, probably best to change this part anyway, and there is a seal kit for the angle gear (oil seals).
Pic of connecting sleeve (new one on left)
Worn splines (worse at the back, just shallow points :( )
Only problem is angle gears don't come cheap, make sure you get the right one as they changed them at some stage (not sure when sorry). And if you're getting a secondhand one then get a pic of the splines!
http://www.ebay.co.uk/itm/Volvo-V70XC-850AWD-Angle-Drive-Bevel-Gear-/360491057335?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item53eef100b7
One here for £100
http://www.ebay.co.uk/itm/VOLVO-97-99-XC70-V70XC-AWD-Bevel-Angle-Gear-Transfer-Case-1023696-/271167816643?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3f22dc83c3
Worst case scenario is that the gearbox splines are knackered like mine were (it is the early engine so the sleeve wasn't glued to the gearbox), hopefully this won't be the case
Worn gearbox output shaft
Gearboxes aren't cheap either, paid £200 for mine from a breakers (on one of those online breaker yard searches) a few years ago.
Hope this helps and good luck :)
Thank you very much for all that info very clear info and photos , I will attack it in the next few days and post my finds once again thx
No worries, thats what we're here for.
[QUOTE=Twincam;584871]Hi I removed the propshaft to see if the awful noise went and it has , very quiet in two wheel drive only The prop and joints seem ok so what I would like to know please , do the diffs give trouble or have I missed something ?? Any suggestions Many thanks[/QUOTE] Here you go. Step by step 'how to'. This will cure your propshaft problem and normal service will be resumed (providing your angle gear is not fooked) http://www.vpcuk.org/forums/showthread.php?21654-AWD-Propshaft-woes-How-to-fix!!&highlight=Propshaft+woes
Hi thank great write up I am waiting for the cv joints to arrive and then will fit them and refit the prop . Cheers
Re the angle drive , I checked the drive again and it is rotating ok , tried to stop it with a lump of wood but it wasn't stopping , I did wonder it the splines was damaged and were catching every now and again . My question is why was the prop not turning . Could it be the the prop had locked due to the front cv joint locking up , it was in a right state , and I wondered if the rear torque had some sort of clutch in it ?? Or am I way off the mark Cheers
OK, firstly there is some sort of 'clutch' in the AWDs. This is attached to the rear diff, and is either the early mechanical viscous coupling or the later electronic Hadex unit. Either way they control they control power to the rear wheels in some sort of way.
Viscous coupling diagram
Haldex unit (shorter than the viscous setup)
Anyway, the propshaft should turn regardless as it is connected via the angle gear/sleeve to the diff housing/ring gear, so even if the spider gears inside the diff break the angle gear is still driven. (see pic below with awd output shaft arrowed)
Now it could be that the sleeve splines are still making some contact with the angle gear/gearbox splines (as you said) and is enough to force a piece of wood out the way, but when the prop is attached its not enough to power the rear wheels and the splines start to slip (thus making a noise). Thats the only thing I can think would allow the prop to stop turning.
It could be that there is something wrong in the rear diff but then the rear wheels wouldn't turn. Best way to test this is just to turn the rear diff input shaft (should be easy enough by hand). TBH I've not really heard of many problems with the rear end of the AWDs, it always seems to be the angle gear or front prop components.
Hope this helps bud.
Will connect the prop today and see what happens , you never know might be working fine just as volvo had intended !! Thx for all the advice Will let you know how it goes
No worries Fingers crossed matey. :D