pantera928

If this has been posted, I have missed it. I have looked at the torque tube clamps for automatic transmission equipped cars and the reasons for needing a better clamp. What comes to mind is that if the tube is pulling away from the flex plate and you stop that with a better clamp, you will still have thrust force pulling the crankshaft towards the back of the engine every time you stomp on the gas as opposed to having the flex plate deflected forward so that you have thrust force towards the front of the engine. Either way should cause excessive wear on the thrust bearing surface wouldn't it? Why do you need a clamp? The tube is clamped at the transmission end. Why couldn't you use something heavy duty with splines similar to Constantine's apparatus but allows the splines to slide inside of it like a clutch disc does? That way the torque tube would never put any thrust load on the engine. Any feedback on this is appreciated. Maybe someone has tried this before and I missed it.

928Myles

IIRC this was one of the options Constantine looked at but couldn't get to work satisfactorily. I think the concern was wearing of the torque tube splines.

Others will no doubt correct me if I am wrong.

Myles

Speedtoys

Yup..ask BMW how well this worked on the K75/100 bikes.

The movement is extremely minor, but..enough that you cant really lube it either and it just eats away at the splines.

pantera928

So do you get thrust wear on the other side of the thrust bearing if you have it clamped and you drive it hard? I don't see why you wouldn't. Maybe Constantine is reading this and has some input.
Thanks for the replies so far.

Speedtoys

It would seem that it slips OUT easier than slipping back into the front fitting...which over a year of BWAHHH, pushes in 2-4mm of badness.

Pagnobito

That's what the flex plate(s) are for, having a loose or no clamp negates the need for the plate, but it is there to cope with the movement.

depami

Sorry, but this is Enzo # what?

Release the pressure once a year and problem solved.

Pagnobito

I would rather it didn't migrate in the first place, hence I have fitted additional clamping.

supercedar

Heavy trucks have used a telescoping drive line for years. There is a grease fitting also for the slide on the splines.
Thomas

Speedtoys

At what RPMs do they operate?


They dont operate at engine speeds, are HUGE...its a physics problem.

Ethre

1k PTO shafts are pretty common. They can take quite a bit of abuse.

Speedtoys

1000rpm?

Thats it?

Ethre

I would assume that the wear from driving at higher speeds on the highway should be equal or less than the wear from bouncing across rocks and ditches. I am no expert on this, but I find it hard to imagine that the stress put on a street car drive shaft would be significantly worse than those on a PTO implement shaft. They get slammed in and out and around and about on a very consistent basis.

Speedtoys

Its not the wear.

You are aware that the driveshaft on the 928 is engine speed.

You cant turn these things at 6500rpm...balance issues become the problem.

And as noted, the movement is barely noticeable..it takes a YEAR of abuse to get 2-3mm of total movement. Its another on the trucks, to have inches of movement.

elgreco