Have any of you guys replaced the viscous coupling?
What I've understood is that it can be done without removing the transmission by just tilting the front of the tranny down.
Do I need to completely remove the drive shaft and tunnel before removing the VC? How would you recommend doing this?
What other new parts are needed than new VC, snap ring for the VC and the transmission fluid? Do I need any other special tools than small and long snap ring pliers?
Does this mean I have to replace the VC and the LSD when the VC leaks or will the LSD start working again when I replace the fluids?

 

Coming to this party a bit late.

It could be a broken torque tube drive shaft which fractures at the transmission end. Once it breaks there is no transfer of power to the front wheels. This happens more often than most realize and is due to how the 993 torque tube drive shaft is constructed.

Here is a photo:

 

Interesting, I have not seen any breakage issues on the Turbos or C4's that have been in the shop (yet). Does this generate any unusual noises or other indicators?

We have been known to get some rain here in Vancouver, and more than once I have felt the front tires clawing at the pavement when in a corner under power, so the viscous coupler was operating. I would not have a 2WD Turbo and drive in the rain, there is too much power to be put down when the traction is not optimal, at least for my driving skills. On dry roads, sure. I had considered a BTR before purchasing the 993TT, and while it was a great car, I did not want to drive that beast in the wet.

There was a thread recently about replacing the coupler in the car in case that is needed. I am sure a search will find it. I did not know that the coupler could leak into the main transmission fluid (as a previous post indicated) - is that true? I thought the unit was outside the oil bath of the main transmission (but still in the case).

Cheers,

Mike

 

Hi Mike,

No strange noises and the only indicator is the front wheels are not driven anymore.

Cheers,

 

WELL THE RESULTS ARE IN. It's the viscous coupler.

Dealer is quoting over 3K for replacement; and I think he's being nice to me.

This is a horrible unforeseen cost. A bit of an eye-opener. Transmission comes out as per Porsche. And I just had the engine and transmission out a month ago for a clutch replacement for 5k. Somebody remind me why we like these cars so much.

 

Dealer?? You are kidding right? that is why it cost so much.

A clutch for $5000? If you did a RS clutch with the right components, the parts are around $2K - so even then that is $3000 labour? That is 20 - 30 hours of labour, that is way overcharging. You need to find another shop.

Get a second quote from an independent if you do not want to do it yourself. Often there are shorter ways to do things other than the Porsche specified methods, since they really do not care what it costs the customer.

Cheers,

Mike

 

Porsche clutch is 60 hours with engine and transmission out as per Porsche. (You must just work fast Mike;
I get the feeling you could do it blindfolded in 60 hours). I did get a LWF too in there but yes indeed the labor was exactly $3000. And that was discounted by 20%

There are no Indys in south central PA. I contacted some and they just either don't seem competent or they have no idea how to work on 993's. Becoming a lost art. I need to travel 200 miles for a good 993 Indy.

Dealer tech is excellent. But he comes at a price.

Thanks

 

Ok, so I did a C2 a while back, dropped the tranny while the engine was in the car, full RS clutch, in and out in around 8 hours, and I took my time. Is a bit longer with a RMS and other stuff, but no more than 10 hours.

The turbo is more work since the AWD tube makes it hard to drop the tranny while in the car, but 60 hours? You can do an top end rebuild for that.

I supposed they want you to pay full list on the parts too?

Ok, sounds like you are in a bind so you need to accept the prices - you know my opinion, I am sure others will chime in.

Cheers,

Mike

 

I speak with limited p-car and mechanic experience but after a major service like shzaaaamm had I would expect them to test the viscous coupler as a standard operating procedure while on the lift. Leaves me wondering about my own VC after spending $$$$ on other repairs. As owners we are pretty much stuck with what's available in our area and the mechanics ethics and experience.

 

You can only properly test the VC on a brake dynamometer:
https://www.dropbox.com/s/pjiibdymnh...2016.24.15.png

My VC showed only 200 N at 3 km/h which proved that the VC wasn't working like it should.

The black transmission oil is also a pretty good indicator if the VC has gone bad after the previous oil change.

 

Much cheaper to rip it out and make it a GT2. I'm biased.

 

Yeah, but I plan on drag racing a lot.......lol

 

Howdie. If you are going to change out the viscous coupler maybe Constantin can talk with the fellow who owns the yellow turbo. He may know about a stronger VC. I'm interested too!!

Jaime

ps the way I tested mine was to raise the rear of the car with floor jack so that rear wheels were off the floor, but front wheels were on the ground. Obviously jack has to be able to roll and be inline for forward roll. give it a little gas in first gear and car should advance forward. I've seen this done on youtube with other vehicles. Mine went nowhere so my viscous coupler is shot too :-(

 

That sounds like a crazy plan à la Ferris Bueller..