Half Shaft Fit

[SteveW]

I know that the half shaft splines have to be a very tight press fit into the rear wheel hubs, however, how tight does the fit have to be at the other end where they slot into the diff? Obviously they cannot be a tight press fit like the hub ends otherwise you could never get them out.

Mine can be slotted in easily by hand rather than needing to be driven in using a hammer.

[ian fletcher]

Hi Steve,
Don't believe that is a problem in fact I'm sure you would do damage to the diff if you had to 'drive' the half shaft in. I've always assumed that the reason for interference fit of hub to half shaft was because if the huge turning force a 19" wheel imparts on the splines of the half shaft. But I stand to be corrected.
Cheers Ian

[Gene Gillam]

Steve, should be a slip fit...sounds like that's about what you have.

[Norman Tuck]

This leads me to wonder why the fit at the hub end needs to be so tight, since both ends of the half-shaft transmit the same amount of torque. Is it because the hub end needs to keep the shaft from lateral slippage? Why did they not just use a pin, clip, or set screw instead of such a tight fit? Or, why go to the effort of making a taper and nut in after market set-ups instead of a pin, set screw or clip if it is only to prevent lateral movement???

Norman T.

[Steve Simmons]

Because if the hub is subjected to the full weight of the car, it will and flex the carrier and damage the bearings. The splines are only there to prevent the half shaft from spinning in the hub. The pressed fit is to support the hub and keep it perfectly level so the bearings aren't subjected to forces they aren't designed for. A loose fit would also allow for movement and flex of the half shaft over the oil scrolls, which would wear them rapidly and cause leaks.

[Norman Tuck]

A convincing explanation. Thanks Steve.
Norman T.

[SteveW]

Thanks chaps. I'm at rolling chassis stage and just about to start building the tub, so I'm going around the car with a snagging list whilst I still have easy access. That's one thing off my list that I don't have to worry about. Lookout for another post soon about the straightness of the chassis as I've been taking some careful measurements.

[dirk w dondorp]

you will find the right dimensions in TCs FOREVER page 97!

[SteveW]

you will find the right dimensions in TCs FOREVER page 97!

Thanks Dirk, I have that book. I'll switch to a new thread to explain how my chassis looks.