machining a car front strut stub axle

[whensparksfly]

was looking for info on machining a car front strut stub axle for a mk2 escort what to machine a stub axle that can bolt to a aluminum block for a one of suspension setup.What type of steel would you use and would it need to be heat treated? what type of aluminum would be used in suspension components?

pic shows the stub axle on the standard setup
thanks for any help

 

[711jrp]

Are you thinking of making wrc type hubs ??

 

[whensparksfly]

Yes just a pity there a bit on the pricey side

 

[711jrp]

If I was going to do it I would probably go for a sierra bearings and hub setup and not the escort stub axle. The reasoning behind this would be, the bearing carrier would be a simple item to machine, essentially just a large cylinder with some registers in for the bearings, it would also be easy to fabricate a upright out of thin plate using the carrier as a start, also the steering arms and caliper mount could be part of the upright. I think this could be just as light and strong as the alloy WRC uprights if anything better as it uses a much more desirable bearing setup.

If I had to make a stub axle I would use 4140 the stuff they make forklift forks out off.

 

[normspanners]

Having had a few of the escort ones especially pinto power shear off i have modded the struts with larger stubs. Right what hubs are you using ? ally group 4 ? I have made and fitted new over size stubs in bilsteins before and modded the hubs for bigger brgs.
I am pretty sure we made them in 16T I would have to get my old diary's out to know the bearings used

 

[711jrp]

@Norn
Seen that happen too, you can get big bearing hubs off the shelf now to somewhat alleviate the problem.But the design is still inherently weak.

 

[normspanners]

Seen that happen too, you can get big bearing hubs off the shelf now to somewhat alleviate the problem.But the design is still inherently weak.

the standard group 4 hubs ally hub ARE bigger bearings than the standard capri cast hub but the id of the bearings are the same ie the od of the stub.
I made bigger dia stubs and modded the standard ally group 4 hubs to take bigger bearings without having to go for different hubs even though i was told it was immpossible but I managed to make it work. I have a stub here somewhere with the new sizes.
The stubs I made stood the pounding of the 30-40 mls Icelandic stages with no problem, with no adj needed, where normally you would have to adjust the bearings after a good pounding.

 

[711jrp]

I understood you made a bigger stub , just got the impression it was a while ago, maybe before the the so called big bearing Group4 hubs were available. I've seen a couple of those hubs let go as well in the past, and put that down to the stub flexing and eventually cracking the hub.

 

[normspanners]

It was not the hub that broke it was the stub usually just after the seal face but also could go at the minor end of the taper.
but in answer, as said, to your OP the material was 16t that was what I used if I recall, it is tough but not too hard to be brittle the struts have to be milled out and the the new stub is let in but goes all the way through and then welded on the back face

 

[Lawnmowerboy]

We machine up a lot of stub axles from en16t if it's any help.

 

[whensparksfly]

Im thinking of using the serria stub and bearings.i wonder which serria has the biggest bearing s

 

[Wallace]

Im thinking of using the serria stub and bearings.i wonder which serria has the biggest bearing s

I know the Sierra rear housings are the same as Cosworth Granada, could be similar with the fronts.

 

[stormin]

Im thinking of using the serria stub and bearings.i wonder which serria has the biggest bearing s

I wouldve thought the four wheel drive variants. If theres room to get a drive shaft through the stub the bearing must be quite large.4x4 Cosworth would probably be the strongest stub axle as well, despite the hole through the centre.

 

[Shox Dr]

Diesels have larger half shafts to cope with the torque. So might well have larger bearings

 

[normspanners]

serria has the biggest bearing s

the 4x4 I would guess.

 

[whensparksfly]

i got a sierra front hub with bearings today i think i will use this and machine a alloy lock to fit the hub and suspension to like the kits you can buy,what grad of aluminum would you all recommend for a very important part like this

 

[whensparksfly]

what grade of aluminum would you all recommend for make the uprights

 

[Shox Dr]

I can't help with the spec.... I know RGD Tools sell big g'lumps of aircraft grade ali, at reasonable prices per Kg

 

[hotrodder]

https://www.google.co.uk/search?biw...11.0....0...1c.1.35.serp..8.3.290.9v3tcRbdcYU The first two hits are of particular relevance. Most of the stuff specific to uprights in those results will be cast from AlSi7Mg (aka LM24 and a356.0) which is, very basically, the cast equivilant of a 6xxx series ally

Also worth replacing 6082-t6 with 2024-T3 and 7075-T6 to see the other two (less popular) suspects although the later will return more stuff about toy cars than real ones. Both these flavours of ally are significantly stronger but that comes at a price, both literally (finding/paying for the stuff) and with regards to stuff like corrosion. Google 2024-T3 SCC for some details on stress corrosion cracking

 

[whensparksfly]

is 6082-t6 good enough for making the uprights ad the steering arms