Testing R180 diff
 

Hi

I'm suspecting that my rear diff on my V5 Type R has "broken" . It doesn't lock up as good as it has done before and the car isn't as tailhappy as a Type R should be. Also when trying to do a donut (just for the testing purpose ;)) it feels like it spins the inner wheel.

I also have a clonking noise from the rear end. But it the wet I still can get the rear sideways.

Is there a way to test the rear diff still installed on the car with a torque wrench?

I saw there is available a STI ring pressure kit. Is this something to go for when rebuilding the diff or is it too much on a road car?

RalliSpec - Differntials


Thanks!

A chat with Paul at Zen may help, and yes there will be a torque figure for the rear diff....

HTH

dunx

Take the LSD out of the rear diff and mount it on one driveshaft held in a vice. Using the other one or even a cv joint from a spare shaft turn the diff with a torque wrench.

Ideally the torque for a road car should be 80 ft lbs [ I do not have a KG/cms figure sorry ] It will be much lower than that.

If you then take the lsd to pieces you can make shims up from steel and fit them on the outer plates [ one in the bottom and one on the top ] and re-tension it yourself. Start at .001 mm or even .0005mm and see how tight it gets. It will loosen off quite quickly on a road car so anywhere less than 100 ft lbs is going to be OK.

There are different thicknesses of lsd plates if you want but theyr are EXPENSIVE - shims are much cheaper.

It will click and hop on full lock for a small amount of time until it settles but using the right LSD oil it will not be a problem

I am here by email to help you through if you want to do it yourself. It is not tricky or difficult to a careful person.

I work with David Forslund Rallying in Sweden, he knows me well if you need a recommendation.

Good Luck - David APi

Thank you for your answers :)

I think the clonking noise comes from the "propshaft joint" (what's the english name?) to the rear diff. It sounded like that when I was under the car today anyway.

That's some great information but I won't be doing the rebuild before I put the car in the garage for the winter season.

I did try to jack up the car so that one rear wheel was in the air and with gearbox in neutral I tried to spin the wheel in the air with my torque wrench. I got about 70 Nm / 52 ft lbs. I know that reading will be different compared to one with the diff held in a vice but perhaps it still gives an indication of some wear?

And what is the correct oil for the diff?

Another member from the Swedish Impreza club has the same problem so I'll forward him Davids name. I think I will be doing the rebuild myself though so I'll get in touch with you again when it's time for that.


Thanks
Juha

Juha, " the propshaft joint " in English is called the " U J " which is short for universal joint.

52Ft lbs is too low, your idea is OK for testing it I think it will be quite accurate.

The correct oil is any make - Limited slip oil. We use Motul 75W 90 which seems to work well.

God luck call me when you need me. David 44 1926 614333