Formula94lt1

Just curious on this one. why not just have like a cv axle where the splined shaft just slides into a female spline and is retained with a clip?

Does the first pinch clamp at the front attach to a shaft that is separate in thrust from the crank or is the shaft coming out of the clutch directly connected to the engine in which case the crank's thrust bearing controls fore and aft movement off the TT shaft along with the trans input? Do I have this all wrong?

atb

On a 5 speed car the stubby intermediate shaft has a nose that fits into the pilot bearing in the end of the crankshaft, and the output end of the intermediate shaft goes into the splined collar that has two pinch bolts, one to hold the output end of the intermediate shaft and the other hold the input end of the driveshaft. Both pinch bolts go through a notch, one in the intermediate shaft, and one in the driveshaft, to keep them from moving back and forth relative to each other. The output end of the intermediate shaft is flat, as is the input end of the drive shaft. I've never noticed how much of a gap there is between these two, but I'm pretty sure there isn't any static load on them when assembled.

I wonder if the long length and small diameter of the drive shaft which contribute to the wind up of the shaft under operation require that the ends be clamped as opposed to just a machine fit tolerance.

atb

GregBBRD

I always thought that the shaft in the torque tube had to be soft, so that it could flex, since it is so long. Being soft, the splines are also soft.

The short shaft that is used in the clutch is much harder, so that the clutch splines do not wear out.

Your question is interesting. The splines on a axle must be hard enough to not wear out....wonder if the whole axle is hard, or just the splined area.

SharkSkin

Adam makes a good point about windup -- if the splines were sliding past one another every time the power applied to the shaft varied, it wouldn't last very long. The tip of the stub shaft that goes into the pilot bearing is smooth and hardened, as is the inner race of the pilot bearing, and with a little grease in there wear is not an issue.

Another point to ponder... CV joints(and u-joints) don't work well for power transmission where there is no angular misalignment. The bearings in either type coupling need to roll back and forth to keep grease distributed over the bearing surfaces. If they were riding in the same small contact area constantly the lubrication would break down quickly and they would self-destruct.

andy-gts

cool, Ididn't know that dave.

Formula94lt1

The corvette has a simple splined shaft that slides in....

86'928S MeteorGrey

Ok. So you offset the torque tube so the CV joints get proper lubrication. But the real problem will be with extra vibration issues, as the drive line spins at engine rpm where CV's historically/generally receive much lower RPM from the diff....

SharkSkin

In any case, a couple of pinch bolts are easier and cheaper to build and maintain than a couple of CV joints.

blown 87

Putting a new motor in because of thrust bearing failure is not though.

SharkSkin

True. An ounce of prevention though...