Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing tool for 2 eared spinner

OK gentlemen, you have convinced me. So I need to buy a hide hammer and invest the rest of the money in a dinner with my wife :-)

+2......not far to plus 4

MG Owners Club spares. The easiest I have found. John.

On Friday we drove the 180 km to our dealer (the one and only in Austria) for the yearly service. He replaced the old octagon spinners with the new 2 eared spinners - wow they look great.
He showed me how to secure them. 2 hits with a hammer and after a short test ride one more hit. That´s it - no additional tool required.

Gerhard
Never a problem putting them on, but getting them off can be a

Indeed, they self tighten but don't self loosen if you reverse up the drive when you want to take the wheels off

It is often said they self tighten. But given the wheels are on splines I cant see how. There is a bit of circular momentum from the ears... but that acts in opposite direction when accelerating and braking... I suppose the braking force is higher than the accelerating force which would net out as a tightening force. But the mass of the ears is pretty small I would have thought it had minimal effect?

By the way, this is an innocent question.... not got an axe to grind

A lot depends on how worn the threads and spinners are. The most I have encountered was when I re-fitted old hex nuts to my old car in preparation fora pit stop challenge. The regulation two taps was applied. By the time I got to Buxton (around 40 miles), it took many whacks and a great deal of effort to loosen the hex nuts in preparation for the ladies pit stop challenge entry.

The mechanics of this are quite simple, but absolutely not what you might expect.

The self-tightening effect comes about because there is a deliberate diameter mismatch between the splined shaft and the hub that sits on it, such that the wheel is moving eccentrically around the splined shaft even as both rotate (if you ever had a 'Spirograph' kit as a kid, this will be familiar). The wheel nut is of course held by the threaded section at the end of the splined shaft.

Even with just a one thou (.001 inch) difference, the relative motion of the nut to the wheel will be 0.003 inch with each wheel rotation or about one turn of the wheel nut in 3 miles driven if you have your shafts/wheels on the wrong side of the car. Of course, you have your wheel nuts the right way round, so the eccentric motion serves to tighten the nut which, at a certain clamping force, will prevent any further oscillation around the splines.

Interesting. Thank you.