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Shelby
30-11-01, 12:06 PM
Can someone remind me whether the Jag drive shafts have to be completely removed from the hubs to replace the u/j s ?

wilf
30-11-01, 12:29 PM
Had to on mine, didn't really consider doing it with them in situ. Let's hope the splines aren't too well stuck in the hub!!
When you reassemble - do it dry first to set everything up, when you are happy, use a Medium (not high strength) threadlock on the splines, otherwise they can move or fret.

Wilf

mark
30-11-01, 12:32 PM
Mark yes i think you will have to ,just changed 4 rebuilding mine , i got them from gordens because its not to far ,changed the lock nuts just for good mesure. by the way thay were 12.50 plus vat (spit) good look

Shelby
30-11-01, 01:08 PM
Thanks for the reply guys, only asked because if i locate hubs with sound wheel bearings, i was going to leave them alone for the time being, but they do have to be shortened, as you well know. :7

alastaid
30-11-01, 02:33 PM
Wilf,

Could you ellaborate a bit more, I could never understand why the splined shaft doesnt "float" a bit, it seems by locking the shaft, you eliminate the ability to tighten the bearings up like "normal" bearing adjustment. I am sure there is a really good reason, I just couldn't work it out.

Thanks

Alastair

wilf
30-11-01, 03:53 PM
I rather suspect it's because of the tolerances prevalent at the time the Jag rear end was first designed. Splines that are bathed in oil, like inside the diff or gearbox, don't seem to have a problem. Splines that run dry, like inside the rear hubs, will fret and chew themselves up because of the alternating directions of torque input (drive/overrun). Thus the recommended way to stop them moving is with threadlock. These splines dry are a loose sliding fit.

LandRover gearboxes (spit) had the same problem on Defenders and Discos when they changed from the R80 to the LT77 (I think) gearboxes - the main gearbox output shaft is splined into the primary gear in the transfer case. Design was such that no oil got to them - and bingo - total driveline failure in under 30,000 miles, especially on diesel manual vehicles with their spikier torque delivery. I made a huge fuss (letters to the press etc) with LandRover when our Defender ground to a halt, because it boils down to a design fault (no oil could get to the splines)and eventually got the cost for a rebuilt gearbox and new mainshaft (1500) back from them. This was a major problem on these vehicles up to around '95.

So - if you don't want your rear hubs chewed up, loctite them. I would advise that you do not do this on first build up - do it after you have set up hub bearing float and rear camber etc. In fact it wouldn't hurt to drive it dry for a while whilst you are running in, so you are sure the back axle is in to stay. Once you have loctited them, they can be a total bas**rd to get out - usually involves lots of heat to break the threadlock, thus destroying all your bearings and seals.

There you go - chapter and verse.

Wilf

FIA Jack
05-12-01, 11:22 AM
Alastair,
Just finished rebuilding a Jag back end.

Re the "floating" and "tightening like normal bearings"

Wish it were so, but the Jag bearings are preloaded by spacer/shims between the drive shaft and the hub. There is no other adjustment. The hub is tightened down hard against the spacer shim (many ft/lbs - 100+) and the end float measured with a dial gauge (some small number of thous).


Regards

Jack