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Modifying steering rack?
Miks15 - 9/7/10 at 05:06 PM

Ive tried to think of many ways to make my BMW hubs work with the escort steering rack, then something clicked today and i have no idea why i didnt think of it before.

Can i cut off the tie rods where i need them, then re tap them to M14 x 1.5 (the thread on the BMW TRE's, will this work fine?

heres a pic of how it sits at the moment




Cheers

Mikkel


blakep82 - 9/7/10 at 05:09 PM

there's something different about the way they're threaded, i forget what it is. they're rolled or something.

anyway, i'd go with ditching the ball joints all together, and changing to rod ends, and extending the rack instead. if you're worried about grit wearing teh rod ends down too quick, you can get little rubber covers for them. anyway, rod ends is what i've got on mine


mark chandler - 9/7/10 at 05:19 PM

That's what I would do!

Just make sure you cut a clean thread.

Its not going to be any different to trackrod extensions.


Volvorsport - 9/7/10 at 05:24 PM

what about drilling the hub straight , using a bolt and rose joint ?


Stott - 9/7/10 at 06:53 PM

quote:
Originally posted by blakep82
there's something different about the way they're threaded, i forget what it is. they're rolled or something.

anyway, i'd go with ditching the ball joints all together, and changing to rod ends, and extending the rack instead. if you're worried about grit wearing teh rod ends down too quick, you can get little rubber covers for them. anyway, rod ends is what i've got on mine



He's right, often the actual diameter of the arms is less than the thread size, so there isn't enough material to put the M14 thread on as it may only be 11.5-12mm diam, if there is though, I can't see why it wouldn't work

ATB
Stott


Miks15 - 9/7/10 at 06:55 PM

I will check again but im pretty sure that the shaft of the track rod it self is 14mm and the threads look cut not rolled.

The problem with the rod end is that it would need to be a 14mm rod end, and the top ot the tapered hole is 14mm so that would need drilling out to at least 15mm, so i would either need an M15 rod end, of make a reducer to bring the hole back down for a 14mm bolt, all of which will become very expensive, as opposed to borrowing an M14 die and putting new threads on, doesnt cost me any more to do!


britishtrident - 9/7/10 at 07:47 PM

Can't be safely done the track rods are made from an imperial size bar stock 1/2" = 12.7mm

The tooling was a hangover from thr Mk1 Escort and every other british car of the 1960/70s that used the same supplier.


Miks15 - 9/7/10 at 09:22 PM

damn the track rod measures 13mm

Anyone know if you can get rod ends with a 14mm thread but a 16mm hole?


smart51 - 9/7/10 at 09:28 PM

Find a TRE with the right thread for the rack and the right taper for the BMW hub. Here's a link to a place with data on track rod ends. Its a bit of a pain to find something that will fit but it will be the neatest solution.


02GF74 - 10/7/10 at 12:02 PM

quote:
Originally posted by Stott

He's right, often the actual diameter of the arms is less than the thread size, so there isn't enough material to put the M14 thread on as it may only be 11.5-12mm diam, if there is though, I can't see why it wouldn't work

ATB
Stott


that is certainly true for the OEM rack.

The Quck rack from Rally Design uses 14 mm bar but rod ends are hardened - good luck to ya trying to extend the thread - I tried and gave up pretty quickly.