Prop shaft orientation

[Darwin]

I have a propshaft that has the roller spline setup (I think that is what it is called). One end is smaller diameter that the other. Does the splined end go toward the back of the car or the front?

Thanks

 

[Don Elliott]

On my TR3A, the flange near the splined end is secured to the output shaft of the gearbox. All the diagrams for the TR3A from the big three TR suppliers' catalogs show it this way. Mine came like this from the factory brand new.

Don Elliott, Original Owner, 1958 TR3A - 50 years this coming May !

 

[DrEntropy]

Yup. "slip joint" at the tranny.

 

[tomshobby]

Probably the primary reason for the splined end to be towards the transmission would be to avoid the stress that would come from the rear axle as it moves in relation to the car. The stress on the splined joint as it carried that movement to the prop tube would be considerable. There would be little stress from that movement with the spline towards the transmission.

 

[Darwin]

Thanks all. Good to know that I got something right the 1st time around.

 

[Rickc]

Darwin
Just sufin' some threads and saw this one and thought I would add a comment. Yes spline end to front of car with lots of grease.
An important point is to have the front UJ and back UJ "synchronized" with each other. I am not sure how to add a picture here so I shall explain the best I can.

If you go to any supplier catalogue and look at a picture of the prop shaft assembly you will see that both halves of the shaft (separate via the spline) have the "C" of the universal joint in the same plain. One is not at 90* to the other as an example. The splines are not "keyed" so you can reassemble out of alignment (sync).
FYI... The rear 2 half shafts are keyed so the UJs can not be reassembled out of sync.
Rick

 

[spit71]

What does sync-ing the u-joints do or prevent? Should I have requested this from the shop rebuilding the prop shaft for my spit?

 

[TR3driver]

A more common term is 'phasing' I believe. It's trivial to do yourself (though any decent shop should know to do it as it's a requirement for all U-joint type driveshafts). What happens is that, if the U-joints are out of phase, you get a driveline vibration while driving. Mostly harmless but annoying.

 

[spit71]

thanks, I'll check for that when it comes back.

 

[Darwin]

I will check for it when I torque the thing down later this week. Had to change out the bolts. I replaced the old ones with slightly longer ones and they rub. Thanks for the heads up Rick. I may just pull it and take it to a propshop and have it balanced.

 

[Adrio]

speaking of drive line vibrations (and I don't want to highjack the thread), does anyone know a way to measure vibration frequency so as to determine if the vibration is driveline of wheel/rear axles?

This thread has me thinking my vibration may be the drive line and not the wheels. I am thinking the modern shops were just not able to ballance my wire wheels when I got the new tyres, despite my telling and showing them all about it.

 

[Rickc]

Ha Randall
Thanks for giving it a proper name. I knew there was a proper name but grey matter could not find it stored.
If not Phased then simply pull apart at the spline and rotate till they are aligned.
Rick