Permanent AWD?

Matt21 · Dec 17th, 2012, 16:28

I'm going to be buying a '97 V70 2.4 turbo awd soon

ive had a read about and see that they are primarily fwd until you loose traction then the rear wheels kick in

im paying £350 for the car.... so its going to get some abuse no doubt, and i want to know if it can be made into be permantly 4wd?

can the coupling be welded up or something? anyone else done this and had any problems?

thanks

mikealder · Dec 17th, 2012, 18:14

If you manage to replace the viscous coupling with a solid link you will break something, it is there to allow for the slight difference in tyre diameter in much the same way as the differentials do on the front and rear axles.

On the old Landrovers (S-III and earlier) you could lock the center diff but ONLY when off road as the tyres would need to slip to avoid transmission "wind up", in the case of a V70 AWD if you eradicate the viscous unit the first part to fail would probably be the angle gear or a rear drive shaft - Mike

Matt21 · Dec 17th, 2012, 19:20

Thanks for the reply mike

I would have thought the viscous unit would just be a 'straight through' connector and not act as a diff?
I'm not sure how to explain what I mean.... basically just joining 2 prop shafts together?

and i thought the rear diff would cause wind up if that was welded

or does the viscous coupler act as a diff between front and rear axel and not the left to right?

iv not come across these before and havnt even seen one in the flesh, it was just a thought id had

I welded the diffs on an offroader i had and that was fine aslong as i didnt corner too fast, but that was just between left and right of both axels not front and back

Thanatos · Dec 17th, 2012, 21:46

I wouldn't do this as it will cause undue stress on the cv joints and the two diffs spinning at different speeds as the viscous coupling spins it takes the stress out of this.

I have only ever lost traction once since I have owned the awd and it was on ice apart from that there's no need for it to be perminant awd.

As long as its got the prop shaft on and the cv joints are kept greesed you will have no probs at all.

byootox · Feb 17th, 2013, 15:03

The same problem arises from front to rear as left to right, if you turn a corner your forcing one of the rear wheels to turn at the same speed as the front, this will cause terrible wind up.
The transfer box won't take that for long unless it was being driven on ice or mud full time to allow slippage though the tyres.
The angle gear and sleeve ain't the best on these to start with so doing this will shorten the life big time.

Dec 17th, 2012, 16:28	#1
Matt21 New Member Last Online: Dec 17th, 2012 20:47 Join Date: Dec 2012 Location: Guisborough	Permanent AWD? I'm going to be buying a '97 V70 2.4 turbo awd soon ive had a read about and see that they are primarily fwd until you loose traction then the rear wheels kick in im paying £350 for the car.... so its going to get some abuse no doubt, and i want to know if it can be made into be permantly 4wd? can the coupling be welded up or something? anyone else done this and had any problems? thanks

Dec 17th, 2012, 21:46	#4
Thanatos VOC Member Last Online: Sep 11th, 2019 14:36 Join Date: Aug 2008 Location: Blackpool	I wouldn't do this as it will cause undue stress on the cv joints and the two diffs spinning at different speeds as the viscous coupling spins it takes the stress out of this. I have only ever lost traction once since I have owned the awd and it was on ice apart from that there's no need for it to be perminant awd. As long as its got the prop shaft on and the cv joints are kept greesed you will have no probs at all. __________________ Classicswede quote " I knew I had not done the bolts up." http://www.volvoforums.org.uk/showthread.php?t=159255

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Dec 17th, 2012, 18:14	#2
mikealder VOC Member Last Online: Nov 6th, 2016 10:18 Join Date: May 2009 Location: Blackpool UK	If you manage to replace the viscous coupling with a solid link you will break something, it is there to allow for the slight difference in tyre diameter in much the same way as the differentials do on the front and rear axles. On the old Landrovers (S-III and earlier) you could lock the center diff but ONLY when off road as the tyres would need to slip to avoid transmission "wind up", in the case of a V70 AWD if you eradicate the viscous unit the first part to fail would probably be the angle gear or a rear drive shaft - Mike

Dec 17th, 2012, 19:20	#3
Matt21 New Member Last Online: Dec 17th, 2012 20:47 Join Date: Dec 2012 Location: Guisborough	Thanks for the reply mike I would have thought the viscous unit would just be a 'straight through' connector and not act as a diff? I'm not sure how to explain what I mean.... basically just joining 2 prop shafts together? and i thought the rear diff would cause wind up if that was welded or does the viscous coupler act as a diff between front and rear axel and not the left to right? iv not come across these before and havnt even seen one in the flesh, it was just a thought id had I welded the diffs on an offroader i had and that was fine aslong as i didnt corner too fast, but that was just between left and right of both axels not front and back

Feb 17th, 2013, 15:03	#5
byootox Premier Member Last Online: Dec 20th, 2021 23:22 Join Date: Oct 2012 Location: Edinburgh	The same problem arises from front to rear as left to right, if you turn a corner your forcing one of the rear wheels to turn at the same speed as the front, this will cause terrible wind up. The transfer box won't take that for long unless it was being driven on ice or mud full time to allow slippage though the tyres. The angle gear and sleeve ain't the best on these to start with so doing this will shorten the life big time.

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