Diff/Pinion Shims

[Chooch84]

Hi,

I'm currently planning to purchase and install a torsen diff for my 940. I'll also be looking to change the final drive ratio later on with my project...

I just wanted to know if anyone knows what the outer diameter and inner diameter of the pinion shims would be and the diff shims? I've seen some online but I can only find one website which states that info.


Kr,


T

[Laird Scooby]

Haven't a clue on the shims diameters, first port of call would be Volvo, second would be the Tor-Sen diff supplier. Alternatively you could just rob the rear diff rom a Jeep Cherokee XJ, they use the same basic Dana diff as the Volvo but have the Trac-Lok diff in the back.

[wade180sx]

You will need to make some set up bearings to get the shimming correct on the diff..As the shims fit behind the bearing.. You will also need a way of mounting the speedo ring to the new diff if you want a working speedo.

I fitted a truetrac in mine and it's awesome cost 520 shipped from USA ...

[Chooch84]

Originally Posted by Laird Scooby

Haven't a clue on the shims diameters, first port of call would be Volvo, second would be the Tor-Sen diff supplier. Alternatively you could just rob the rear diff rom a Jeep Cherokee XJ, they use the same basic Dana diff as the Volvo but have the Trac-Lok diff in the back.

Good shout! I'll have a look to see what they have around, pretty sure I've seen some sites that cater the off roading scene that may stock shims for Jeep's.

Originally Posted by wade180sx

You will need to make some set up bearings to get the shimming correct on the diff..As the shims fit behind the bearing.. You will also need a way of mounting the speedo ring to the new diff if you want a working speedo.

I fitted a truetrac in mine and it's awesome cost 520 shipped from USA ...

Thank you for the tip! I guess this will be another steep learning curve.

Not really worried about the speedo ring as the kit that I'm looking at comes with one that I can weld in place after positioning it and truing it out. Just worried about not having everything I need around me for when I start ripping things apart, I don't want to keep the 940 off the road longer than it needs to be.

Is the truetrac a torsen diff? Never really looked too closely at them, the one I've seen is from sweden, it comes with new bearings etc. Haven't really seen any comparisons...

[wade180sx]

Truetrac is a helical diff like a quaife. The beauty of it is that is behaves like an open diff the rest of the time so no jumping around in car parks when parking.

[wade180sx]

I bought a spare set of bearings and honed the middles out with my die grinder so I could push the bearings on and off with my hands. That way you can use them to get the shimming right and then once it's all correct fit the other bearings ..
You also have to remove all the rear brakes including handbrake shoes so I ordered a new set of brake clips and pins as they are normally rusty as ****..

Plus you have to remove l/h and r/h drive shafts so you may need new hub seals if you catch them with the drive shaft on the way out ...

[Laird Scooby]

Originally Posted by Chooch84

Is the truetrac a torsen diff?

Yes, if you look at both of these :

http://www.eaton.com/us/en-us/catalo...ferential.html

Nice little video halfway down explains it with graphics as well.

https://torsen.com/how-it-works/

Looks identical in manufacture and operation to me!

This WIkipedia link explains the different types :

https://en.wikipedia.org/wiki/Limited-slip_differential

I believe (but not sure) the optional Volvo LSD was a clutch type, same as the Jeep Trac-Lok. I know Jeep changed later to a different sort (Posi-Trac i think they called it or something similar) that was more of the Tor-Sen type.