Pressing Out The Stub Axle?

[Duk]

Has anyone ever pressed out a stub axle from the spindle/upright? They are definitely a 2 piece design, but I'd like to know the likelyhood of damage when doing it cold and an idea of the required force to do it.

[Mick A]

If you have a problem with a worn or damaged stub axle, my advice is to throw the upright away and replace it with another. Not worth the risk.

Mick.

[Colin Byrne]

100% agree with Mick, the bending moments that go through stub axles are huge, and a failure is going to be catastrophic, just find a replacement, there are plenty around. The 105 stub axles aren't the stiffest in the world to begin with (we run a large "crush tube" between the 2 bearings to stiffen them up and help with brake knock back). I had a brand new stub axle fail on an open wheeler once, the cause was as simple as not having a large enough radius on an edge, the result was a very damaged vehicle that took us months to repair, but luckily no injury.

cheers

[LaStregaNera]

we run a large "crush tube" between the 2 bearings to stiffen them up and help with brake knock back

I vaguely recall seeing someone who manufactured these - or did you machine your own?

[Colin Byrne]

yea we ended up machining our own, they have to be very accurate so we also got some shims made up in case we need to change wheel bearings when we don't have access to a lathe, that said last time i changed wheel bearings there was need for adjustment anyway

[Duk]

Alrighty.
My interest in removing stub axles is so I can either machine the original ones or machine new ones to suit Series 4/5 RX7 Turbo wheel hubs.
This is intended to be a bit of a combination of parts. RX7 hubs on 105 spindles installed in a 75.
I'm looking to use 105 spindles in a 75 because of their bolt on steering arms. I want to have faster steering (fewer turns lock to lock). To get the 75 to a 2.5 turn lock to lock steering instead of 3.25, I'd need steering arms about 30mm (I did do the maths, but can't remember exactly) shorter than the 75 arms.
This will work so long as having the track rod at a slight angle forward doesn't ruin Ackerman angle behavior.

105 stub axles are larger in diameter and longer than the 75 stub axles.

[LaStregaNera]

I doubt you'll have much luck pressing them out. I recall someone tried to press out the 116 stubs - deformed the axle and maxed the press without moving anything.
Bearing swap? Custom hubs?
These are the guys I saw who did the bearing spacers - they also do a big bearing hub conversion:
http://www.msfracingcomponents.com.au/bigbearingfronthubs/
http://www.msfracingcomponents.com.au/stubstiffenerbearingspacers/

I note they don't appear to list the stiffner for the 105 anymore (or maybe my memory is fuzzy and they never did it?), and just realised they have a picture of a 116 stub...

[Duk]

I have a little 12t press at home.

But there are much bigger presses at work! 

My reasons for looking into this are written above.

[LaStregaNera]

Well, give it a burl then.

[Colin Edwards]

Might the stub axle be shrunk into the upright?

I'd only be guessing at the Class Of Fit, however given the criticality of the joint, heating the upright and cooling the spindle would make sense.

[LaStregaNera]

Might the stub axle be shrunk into the upright?

I'd only be guessing at the Class Of Fit, however given the criticality of the joint, heating the upright and cooling the spindle would make sense.

It most definitely would be shrunk. I suspect the only way to get the stub out is to bore it out till the shrink fit collapses.