Problem with viscous coupler (9183905) V70R AWD mk1

[rise94]

Hello everyone,

I encounter a problem with a VOLVO garage which tells one of my friends, after diagnosis, that the visco-coupler of his VOLVO is dead.
It does not justify his diagnosis, it is not very clear .... My friend wishes a second opinion and will see next week another garage VOLVO.

To sum up :
My friend can ride with the car without any problem, he made 140km to go to the garage. He did not hear any particular noise.
He tells me that the car makes noise when turning, like a rolling sound, at low speed and nothing else.

This noise I got it also when my transmission shaft (I also have a V70 R AWD) to start dying.
When the silent block of the transmission shaft begins to die, it ends up putting play in the spindle of the transmission shaft and must therefore be changed.

I wanted to know if any of you have ever had a breakdown with the viscous-coupler and if so what symptoms did you have?
- Is the transmission blocked when the viscous-coupler is dead?
- Is the viscous-coupler making noise when it is going to die?

I have no feedback on viscous coupler problems.

Thank you in advance.

Yann

[Dangerous Dave]

Vibration/noise can be from other components. The bearing on the propshaft and the front CV joint on the propshaft are common wear points. Also the connecting sleeve on the angle gear wears down.

[rise94]

Thank you for the answer Dave .

I got that as an answer too :

The viscous coupling tends to make a clunk when taking a high speed curve when it's failed. Other common symptoms will be a clunk when reversing or a clunk when slowing to a stop (at very low speed just before stopping).
If the sound is always present but sounds like it's coming from where the viscous coupling sits, then it could be the bearing that is behind the flange on the torque tube (the housing that holds the viscous coupling). The bearing is very inexpensive and can be changed. These kinds of noises can also be a worn angle gear or even a worn bearing on the passenger side driveshaft although I think that one would be easier to pinpoint given where it is.
There is a test to check if the viscous coupling is functioning properly by lifting one of the front wheels off the ground and then measuring torque at one of the rear wheels by turning it. Volvo says it's supposed to remain above 50 Nm through the turn and anything less than that implies damage to the VC.

Hope this helps to figure out the problem.

And I have answered :

Hi Will,
Thank you very much for the answer. I did not know the procedure VOLVO, now yes!
I passed all the information to my friend but the garage VOLVO (It is nevertheless the garage VOLVO .....) never wanted to do the procedure! .....
They still removed the transmission shaft to isolate the noise and ... actually there is no more.
I said that it came more from the transmission shaft than from the viscous coupling .
The noise you made Will was not there.
It's a shame that VOLVO is not willing to do the procedure to isolate the problem. On the other hand they offered to buy a more recent model ..... That's where we are in France ... regrettable.
My friend went away with his VOLVO without his transmission shaft and without knowing exactly where his problem came from. He can actually ride in 2 FWD.
Thanks again WIll