S/C car front hub end float - where to measure?

[Mjit]

So changing the brake disks on my Spitfire at the moment and checking the (original Triumph) workshop manual for any gotcha's noticed it gives the front hub tightness as an "end float you can test with a dial gauge".  Now I know almost nobody's ever done that and everyone uses some variation of "hand tight then back off till you can get the pin in" or "you should be able to rock the wheel and feel, but not see some movement" but it got me wondering where you're actually meant to measure that end float.  Clearly the further out from the stub axle axis the greater the measurement will be.  Googling someone said you measure against the castlated nut...but that's screwed on to the sub axle so would only be measuring play in the screw threads, not the hub!

Just out of interest as much as anything does anyone now?

[edit]...and waiting for another build to run so more Googling: Or is the correct set-up to clamp the dial gauge base to the brake disk/dial gauge pointer on the end of the stub axle?  As your measuring point is in line with the stub axle axis I don't think where on the hub the base is mounted would matter to the reading?[/edit]

Edited June 6 by Mjit

[johny]

I dont think its critical mate as long as theres some play to indicate the bearings arent clamped up. I try to get the minimum I can and still get the split pin in - if I tighten the nut one more hole round theres no play so back it has to go....

[Mjit]

Like I said, it just got my mind wondering how you were 'meant' to do it - as opposed to how everyone does do it

[johny]

ok the manual says 3 - 5 thou end float so do up the nut with a 3 thou feeler gauge between it and the washer until theres no play. Then back off to the nearest split pin hole, insert pin and remove feeler.... 

[Mjit]

Popped out to oil the trunnions while the cars up in the air/wheels are off and thought I'd try clamp stuck to disk/dial gauge on end of stub axle.  Set it so as much wanging around on the hub I could do was giving a ~0.005 swing, put the wheel back on and...clear visible movement and quite a clunk wanging on the wheel so clearly not the 'correct' method!

[Paul H]

I bought these Shacktune spacers for my Vitesse 

https://www.ebay.co.uk/itm/143226142059?
Paul 

[Mjit]

I'm always a little paranoid about my front hub end float after a friendly MOT garage once told me "You had a lot of play in the front hubs but we tightened them up for you rather than failing it", which seemed like someone being helpful...until an outer bearing friction welded itself to the stub axle which "succumbed to physics".

[Pete Lewis]

any garage that removes end float will quickly seize the outer to the stub as you have found out , 

i have for years whatever car with floating taper roller brgs  light hand nip of the castle nut , back off 1 or 2 flats 

so you can detect rock at the wheel rim , insert a new split pin and ...drive it 

the bearings must be free to rotate on the stub axle  the D washer removes any rotational forces on  the nut

rear hubs with a single row brg. must rotate in the brg. housing .

this allows small levels of rotation so the load is never in the same place .

if you fit solid spacers to the front then this design cannot work .

Pete