Black Sea RD

Some might remember that we have been working on a fix for 993TT and 993C4 torque tube broken drive shafts which eliminates the four wheel drive function. We found this problem when we were R&Ding our 993 Super Bearings for the 993 torque tube.

We found a customer with a Yellow Euro 993TT making 650 HP (!) willing to install our fix so he could get his four wheel drive back. He sent us a picture of what his technicians found at Vision Motorsports when they removed the engine and transmission which clearly showed a torque tube drive shaft fractured.

Our rebuilt torque tube with our new 993 drive shaft fix and 993 Super Bearings was installed in his 993TT at Vision Motorsports. The owner is back to four wheel drive and having fun again. He said he has to re-learn how to drive the car with the four wheel drive working.

Just thought to pass this good news along. Now 993TT and 993C4 owners have another option than a remanufactured Porsche unit which doesn't address this problem.

Here are some pictures showing a broken torque tube drive shaft, our customer's 993TT showing the common drive shaft break and our drive shaft fix with our 993 Super Bearings installed in a torque tube.

Black Sea RD

We received some pictures of the customer's Euro 993TT during the torque tube R&R at Vision Motorsports. Thought some would find them interesting.

Bottom picture is of the broken drive shaft end at the transmission from the customer's car.

Mike J

Interesting.

Its hard to see where exactly your fix goes and how it works - how is it much different than welding the joint up and heat treating the shaft? Is your product a clamp, or ?

Cheers,

Mike

Black Sea RD

Hi Mike,

Thank you for the question.

We studied the problem and given the failure and the construction of the Porsche drive shaft, decided against welding since it would probably fracture again.

We R&D'd new drive shaft splined ends from a stronger heat treated material with increased length that goes into the original Porsche drive shaft. It is then mechanically captured with bolts to secure it to the Porsche drive shaft.

This way there aren't any further concerns of fracturing of the original material around the fix due to welding. Metal can only be super heated so much without becoming brittle.

Obligatory photo. Our new drive shaft splined end installed into the Porsche drive shaft over the old fractured splined end:

PrivateParty

I saw this post and just wanted to add my $.02 as the owner of the car shown/mentioned. As Constantine said, the car is running around 650HP. The car, today, only has 31K miles on it but about 10+ years ago, after all the modifications, I suddenly started getting a lot of rear wheel spin. Looked into it and it had blown out the viscous coupling. Replaced that with a stronger than stock version and got back the AWD. Very little time went by and got the rear wheel spin again. Talked to Dwain at Vision and agreed it probably just had too much power for even the stronger coupling. We left it at that and I just had to get used to driving it with RWD only. With that much HP it could be a lot of fun but also had its drawbacks as I like to have fun while driving it. I mostly drive it to and from work and getting it sideways in rush hour traffic always got some interesting looks. Like I said, it was fun, but I especially missed the feeling of the car pulling through corners instead of pushing. I didn't take any of the now extra rotating mass out as I still wanted to figure out the AWD, and hoped someone would make an even stronger coupling. No luck, at least that I found.
Then, about two years ago I took the car in for a major service/inspection. Low and behold when they got under the car they discovered that the driveshaft had actually snapped just forward of the transmission. After all those years, it wasn't the coupling after all. I made lots of calls and did a lot of research. Got various answers but no solution other than a new torque tube which is not cheap and would not be any stronger. One day I saw a posting on this board talking about a potential fix at BSRD. I got in touch with Constantine and he told me they were just in the early stages of something for the 993. Told me to check back later. Well, about 3-4 months ago I did and found out they had just finished their 993 project and were ready to try it. I jumped at the chance and a few weeks ago I got the car back from Vision with the AWD again.
After driving it all those years with just RWD and then going to AWD--what a difference. It now pulls through the corners again and acts, and reacts, completely differently. I had also modified the suspension years ago and never really got to drive the car like that with the AWD until now. I have almost had to learn to drive it again all over. Lots of different feelings and sensations. I have only been able to put about 200 miles on it so far but everything is fine and back to "normal". Enjoy it every time I drive it. I still have fun--but in a straight line these days (and without the smoke and tire wear). Keeping my fingers crossed that everything in the drive train holds up but thank you Vision, BSRD and Constantine!

ttAmerica RoadsterAWD

Hi Private Party. Sounds like you're back in business! I do have to ask what stronger than stock viscous coupler did you use? I thought only stock version was available. Can you tell us more??

Jaime

Black Sea RD

Hi Jaime,

PP doesn't hang out here too much. We sent him a message about your question, but know he is quite busy at the moment.

Suggest you contact Dwain at Vision Motorsports 949-770-2888 or www.visionmotorsports.com for help with your question. It was Dwain who we believe sourced the stronger vicious coupler and installed it for PP.

Cheers,

ttAmerica RoadsterAWD

Hi Constantin. Thank you for the lead. Will follow up :-)

Jaime

PrivateParty

Constantine is right, on both counts. I do not know what was used and it was several years ago. Definitely give Dwain a call and he can help you out. I am leaving in a few minutes and will be gone for two weeks but I will also try to get more info when I return.