Soooooo had Kevin's clutch & LFW installed @ dealer; smooth all went well. Thanks Kevin...excellent product.

But driving home today I had to traverse my snow covered driveway. This is no small feat. It's about a 20 degree incline and over a football field long. My Jeep wrangler, Infinity SUV, and Cayenne TT make it up no problem with no sliding and hardly any detectable wheel spin.

I barely made it with the 911. Without my momentum / head start I would have never made it. BUT what is most interesting is that I perceived no help whatsoever from the front wheels. When I did get to the top (feeling all proud of myself that I made it) I tried to back it into the garage as i always do except this time in 3 inches of snow and it wouldn't move in reverse. Then even in first it mostly went sideways and took about 10 solid minutes to effectively complete a 3 point turn on a flat surface to maneuver it into the garage. Backing it in would have been impossible.

My point is: no help whatsoever from the front wheels on snow at all. Back wheels just spinning. Is this normal? At one point the two front tires were on dry pavement and it still wouldn't move (backs just spinning wildly).

Now I know a 911TT isn't exactly a 4x4 BUT I'm using my old 3000GT vrfour of my youth as a reference...that AWD sports car was a beast in snow...it would go anywhere....my 911TT is absolutely NOTHING like that.

So do i have a problem?....are my front wheels "not working" or am i doing my usual over-thinking of things?

 

From what I have read, the differential uses a silicon based substance that hardens when heated. It also has a limitation of how much torque can be supplied due to the shear capability of the silicon substance. Therefore it can only transfer 39% of the rear torque before failure. It can fail and the assembly needs to be replaced not repaired.

I read this in the 993 Essential Companion. No idea if yours has failed. I guess the test would be having the front tires on solid pavement while the rears were on ice and see if it crawls out of it.

On my last run in inclement weather back in Nov '13 I got on it a bit on a wet and leafy road and the car seemed to power drift. I let off right away, but it felt to me for a brief second that there was torque being applied by all wheels. I could be just imagining it though.

Good luck on your investigation.

Johnny

 

Failure of the viscous coupler is quite common. No real symptoms other than no AWD. This sure sounds like what you are seeing. I'm not sure what the substance "snow" is, but it sounds cold and slippery.

 

Hell, right now I forgot what rain is.

 

Any car with z-rated tires is absolutely useless in anything resembling a dusting of snow. With proper snow tires the 911 is a joy to drive in the snow!

 

Jack up the rear jack point enough to get the front wheel off the ground a smidge. Hand turn the rear wheel. Does the front wheel rotate too? Then you know your VC is fine.

 

I read this in the 993 Essential Companion. No idea if yours has failed. I guess the test would be having the front tires on solid pavement while the rears were on ice and see if it crawls out of it.


Johnny[/QUOTE]


That exact scenario played out. It didn't budge.

 

Thanks very much. I will do exactly that.

 

Funny I think Steve is in Del Boca Vista

 

You have an issue either with the VC or the front diff, last opportunity to run in the white stuff it dug in and had no problem in up to 6 inches of the cold powdery substance, you should at minimum feel
a torque steer like resistance if the front wheels are slipping, try topping off the mineral oil in the front reservoir... Bert

 

Did the two rear wheels on snow and front on dry again test last eve......was easiest thing to do. The fronts don't turn. The car's rears spin until they dig through the snow to get traction; then it crawls out using only the rears. Used a spotter (wife) as well to observe any life from the fronts.

I have to have a bad viscous coupler???


And i was literally driving it home from a clutch change!!!!!!!!!

Why no CEL?

 

The viscous coupler is strictly a mechanical device... no electronics involved. There is no CEL for a failed coupler. Kinda like no CEL on a worn clutch.

 

CEL (check engine light) has to do with components relating to vehicle emissions.

 

I just loaded up this little video I made while servicing many things in my 993tt. I recently replaced the worn LSD to a upgraded CMS vrsion with more lock up %.

You should make a test like this and see if the front wheels spins when moving the rear ones.

 

Thanks!! but I don't have a lift.

Would it work if i just got two wheels on the same side off the ground or do i need all 4 for this test?