Tails

Dr Bob & Constantine,

Thank for the advice regarding the shape of the splines especially your BTDT explanation Constantine.

Does anyone know of any failures after fitting an improved clamping device?

Back on track regarding Wally P's original suggestion, if there has not been any failures after fitting a more effective improved clamping device, one would ask the question, does Wally's idea have merit.

I believe that it has, because if the flex plate maximum spring force exerted on the crankshaft thrust bearing faces could be reduced then the likelyhood of the existing flex plate clamp migrating and the possibility of boundary lubrication occasioning is reduced and therefore wear to the thrust bearing faces could be reduced and thrust bearing failure would be mitigated.

I watch this space with interest.

Tails 1990 928S4 Auto

Black Sea RD

Hi Paul,

Thank you for the kind words about our Super Clamp.

Yes a sliding coupler device, like a clutch pack, will work fine. That would be another great solution and is why we went down that path initially.

However the cost of the finished product to do it up right will not make it feasible to continue development.

We really did look at this problem from a lot of different angles, even with a device like PorKen's helper clamp. We finally decided to settle on what we considered to be the very best solution within an acceptable price range.

Cheers,

Imo000

If all 3 alternatives stop the driveshaft from moving then, to me, they are all equally as good and there is no ultimate. To install the Super Clamp the TT has to come off and thats' a big drawback. Proken's on the other hand is much simpler and so far does the job just as well but the Loctite fix is the least expensive.

Black Sea RD

Hi Imre,

Each method works differently and has it's own drawbacks:

1. The loctite fix is not easy to un-do or to re-adjust if needed. But it is cheapest and the easiest to do.

2. The PorKen type relies on the health of the original clamp too much. Our tests with using this type of "helper clamp" made us look for an alternative. But it is cheaper and easy to put on.

3. The Super Clamp is too costly for some and the TT needs to be dropped to be installed. But it sure does work well.

Hard to argue with cheap.

Your reasoning should give some pause if they ever think of making new parts for the 928.

Cheers,

OBehave

I think in this case the word ultimate is being used instead of the best.From an engineering standpoint of the 3 types of clamps here,the super clamp is the best.It provides the most clamping force equally and evenly distributed around the 360 degree shaft. And as in anything else,if you want the best be prepared to pay more for it.If the fix is easy to do it may not be the best and if cheap is the main reason then I can't argue that. It's like buying a helmet for racing or motorcycle riding. You can buy a $5.00 helmet or a $500.00 helmet,which one do you think will protect your head in a crash better? If you have a $5.00 head,well then buy a $5.00 helmet.

inactiveuser1

Looking at one more possibility on a clamping anyone have the od sizes on the area marked on picture and also length.Haven't seen the other clamp but need to know the sizes 1st.

Mike B

Well written...I'm not sure one really appreciates the engineering of the Constantine Clamp (C-Clamp), now refereed to as the Super Clamp, until you actually install it. Once you snug down a C-Clamp you'll be a believer.

No affiliation...simply, a satisfied consumer.