Just done a trial fit of my front suspension and realised my Sierra hubs dont fit my Cortina ball joints.

I'm assuming I can just open the holes out a bit? What is the best thing to use? Has the taper got to be the same (ie can I just use a reamer?)

Cheers - Chris.

Sorry steve
I believe that the ball joint of choice is Vauxhall Astra, not sure which model.
Chris PTM

So can I make them fit then? No idea how to 'drill' a tapered hole

BTw I'm Chris, not Steve?

Chris

Tapered reamers, which you would need, do exist, I have seen them on a US web site but their tapers are defined by so many inches per foot, not much good unless we know what the cortina taper is. I notice the Lolocost lower wishbones for sierra hubs have a different looking (pressed in?)ball joint, so those are not going to be suitable for standard wishbones. I look forward to someone posting the definitive answer to this
John

You can get tapered drills m8, ask at eng shop and they will tell ya where, then just drill away and keep checking for fit

I guess what we need to know now is, what's the cortina balljoint taper?

The whole idea of the taper is to ensure a good tight fit between the ball joint and hub trying to mod with a reamer/tapered drill not a good idea, anyway its probaly no more expensive to buy the right joints than a special reamer/drill.

wicket

It's not a question of price, it's a question of which design of balljoint is convenient to fit. The sierra bj (and most other bjs from macpherson strut cars) is designed to be pressed into a track control arm, the cortina bj bolts to the cortina, or in our care Locost, lower wishbone

Also, I already have my lower wishbones, Sierra hubs and Cortina bottom balljoints (from Lolo BTW). We have reamers at work but I've not idea what tapers. I reckon I'll work out the taper of the balljoint and see if I can get someone to drill it with the same taper. Is that a good idea?

Chris

Sounds OK to me, Chris. Let us know if you get anywhere with this. I figure the tapers must be standard ones. Somebody, somewhere must know about this stuff, but the couple of times I've tried to find out I've got nowhere. Good luck
John

Got a contact at a precision engineering place who did my threads for my top wishbones (after Loloquality made such a fuckup when they cut them). I'll pop down there on Wednesday and see if he can sort them out. If not, there are a few reamers at work so I'll have to find the closest fit.

Will post on here when it's sorted!

Chris

I remember seeing on a friends MK3 Fiesta that the ball joint although pressed between two plates of metal also appeared to have a couple of bolts holding it in place so I'd guess you may be able to remove it from the wishbone.
Basically, you've got the vertical (that goes into the upright) and that attaches to the end of a (approx.) 3" by 1" strip if metal. It's this strip that is clamped and bolted.

My thought was that it might be possible to use this by welding/bolting this strip to your wishbone.

Obviously this depends on whether it's a compatible size but from memory (and having now seen the Sierra ones) it looks about right.

Hope that helps- if not I'd like to know why as I'll need to come up with something for my Sierra uprights!


James

I chopped up the lower control arm from the Sierra and drilled a couple of 10mm holes in it. This is now bolted to the bottom wishbone. I had the added reason that the 4x4 front hub has a different ball joint to the RWD version.

You can see some pics on my site in stage 10. http://www.fk2.co.uk " target="_blank"> http://www.fk2.co.uk

Austin Maxi ball joints fit straight into sierra hubs as far as i am aware.

I would have thought that there would only be so many different tapers, just as there are standard engineering threads. Surely Ford etc don't just dream up a new taper for each car they make? Someone, somewhere must know about this stuff.
John

Ahh but will they fit onto my wishbones?

Chris

quote:

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I chopped up the lower control arm from the Sierra and drilled a couple of 10mm holes in it. This is now bolted to the bottom wishbone. I had the added reason that the 4x4 front hub has a different ball joint to the RWD version.

You can see some pics on my site in stage 10. http://www.fk2.co.uk " target="_blank"> http://www.fk2.co.uk

---

I also found that the taper on the bottom of the sierra hubs is different from the cortina.

I measured them by taking the hole dia at each end, and the distance between them. this gives something you can calc the angles from. Essentially one was summat like 4 degrees, the other was 2.5 degrees. And the stud size is different.

It does not sound a lot, but if the taper is different the joint wont bed - you will get a tiny point contact that might cause some kinda nasty shear load on the stub. Im an electronics guy, not a metalurgist, but when i upscales the tapers and made cardboard cut outs of em you can see the huge lack of fit between the two.

all the tapers I tried to find were way too shallow an angle.

atb

steve

Chris! If you need the wishbones modified just let me know! I can always re-sell yours to a cortina hub car and re-make to suit whatever you need!?