Ive been searching the various forums about 996TT Differntial Troubleshooting with little succcess.

There are lots of opinions about the AWD functionality on the 996tt ranging from complete removal for weight saving and parasitic drag to leaving it as Porsche intended. Although it is obvious when there is a catastrophic failure- there really isnt any information about how to determine if your front differential is working, and if so, at what capacity.

The facts are that its an AWD system that can transfer anywhere from 5 to 40% pending conditions and load and that dynoing on a 2WD system (and some AWD models as well) can grenade your differential. Interestingly, there is also specualtion that using the spare can also cause damage which is why it wasnt included on the 997s (hearsay).

Bottom line: Does anyone know how to determine if the front differential is working, and if so, how do we know at what capacity?

Any constructive input appreciated.

Btw, my differential appears to be fine, although I have dynod on an awd system, and used the spare a couple times

 

I've always wondered if my front diff was working also.
Because the rear spins out so easily for me. I can easily do donuts too.
So I put it on a hoist and put the car in 1st and all wheels were spinning.

 

Thats an easy way to test if the diff is working at all.

I wonder if a dyno would have a way to test the % of difference front and rear....hmmmm

 

I seriously doubt the viscous coupling (not the front diff) can transfer 40% torque to the front wheels. No matter what Porsche says.

This is the 997: http://www.youtube.com/watch?v=urnGh9Gek2k

Thsi is the 996: http://www.youtube.com/watch?v=MGaSNLh9B_Y

You are hard pressed to see the front tires spin at all on the 996

 

I think I'm doing the 2WD conversion on mine at GMG. It includes GT2 stub axles and PSM reprograming.

 

I thought PSM works fine w/ no programing when converting to 2 wheel drive?

 

Fabrice at GMG told me it needs to be reprogramed.