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Escort Rack Extensions
flak monkey - 21/2/05 at 05:55 PM

Can anyone tell me what length their track rod extensions are for wide track, escort racked cars...

I should be able to make myself some...so just need some measurements (length mainly), can someone help?

Cheers,
David

Stu16v - 21/2/05 at 08:21 PM

Sory to be pedantic, but it depends on how much wider the 'wide track' is....

flak monkey - 21/2/05 at 08:23 PM

Yeah sorry, I guess I should have made that clear....

I mean for the Sierra based cars that use an Escort rack...like the GTS.

David

britishtrident - 21/2/05 at 08:59 PM

Just buy a set it is too critical a component the quality of the thread cuting and grade of steel required mean making making a pair is real not on. If you look at the standard rack you will see the thread on the rods is rolled not cut.

craig1410 - 21/2/05 at 09:27 PM

GTS sell them for their own car I think and they don't cost much. Check the GTS website for details.

Personally, I'm building a McSorley 7+4" chassis and I got a pair of extensions from "907" on the forum here. I'm not sure if he's still making them as I think he has been very busy lately building exhausts for everyone but the quality was excellent, in particular the threads. I don't want to say what I paid for them as prices do change but lets just say they were a bargain!


Cheers,
Craig.

ps. Ask yourself what you'd do if they were to break?? The answer I came up with was, "Crash!!!"

JoelP - 21/2/05 at 09:28 PM

me too (from paul), and as craig says, a lovely well made part.

flak monkey - 21/2/05 at 09:43 PM

OK i will buy a pair then. The GTS ones are £16 a pair.

I could fairly easily make myself a pair from EN16 bar on a lathe. TBH I dont see the problem with cutting the threads as long as it is done properly. I know rolled threads are stronger, but is that extra strength needed here...?

I would think the threads are only rolled on the rack because it is quicker and more economical to do this on a commercial scale (look at all the bolts you buy).

Im not trying to justify that its ok to make myself some, just trying to understand why it is really necessary to buy them....

Cheers,
David

JoelP - 21/2/05 at 09:50 PM

for me, cos im a lazy bugger and couldnt make them anyway! maybe you could!

craig1410 - 21/2/05 at 09:58 PM

Here's a picture of my extensions in place. Sorry I thought I had a close up of one. Drop a U2U to 907 (Paul Gooderham - nice guy!) and I'm sure he'll be able to fix you up. I'm sure it will be a change from building exhausts... Make sure you tell him I said that, he'll appreciate it!

Cheers,
Craig.

[Just saw the last two posts - Looks like you've decided on a course of action. 'nuff said]




[Edited on 21/2/2005 by craig1410]

niceperson709 - 21/2/05 at 10:44 PM

Extending these is an issue I am going to have to tackle very soon but as I am building a plus 2' frame and due to my rack placement I think that I will not need much more than one inch or so on each side my question is this would it be OK (from a strength point of view) to shorten the tie rods slightly taking all but say 20 mm of the threaded end off and making the extention with a long male portion to allow adjustment . (hope this makes sense)
altenatively I seem to remember from some where that cortina tie rods are longer than the escourt ones and that they have the same size ball end so they could be exchanged for the Escourt ones to give extra length . If any one can confirm this It would be apreciated
best wishes
Iain

Stu16v - 22/2/05 at 06:04 PM

quote:

TBH I dont see the problem with cutting the threads as long as it is done properly. I know rolled threads are stronger, but is that extra strength needed here...?


Good question. The threads in the TRE's themselves are cut...

britishtrident - 22/2/05 at 06:19 PM

quote:
Originally posted by Stu16v
quote:

TBH I dont see the problem with cutting the threads as long as it is done properly. I know rolled threads are stronger, but is that extra strength needed here...?


Good question. The threads in the TRE's themselves are cut...


They are internal the stress raiser and fatigue issue dosen't occur to anythng like the same extent, I am not saying the threads can't be cut just the quality and finish of the thread has to be spot on .

britishtrident - 22/2/05 at 06:27 PM

quote:
Originally posted by niceperson709
snip I seem to remember from some where that cortina tie rods are longer than the escourt ones and that they have the same size ball end so they could be exchanged for the Escourt ones to give extra length . If any one can confirm this It would be apreciated
best wishes
Iain


70s Cortina,Garnada,Fiesta and Escort MK2 track rod ends are exactly the same part number. Sierra ones are longer, some Volvos use the same thread as the Rover SD1 (P76?) but I don't know about the taper size

MikeRJ - 22/2/05 at 09:57 PM

quote:
Originally posted by niceperson709
I seem to remember from some where that cortina tie rods are longer than the escourt ones and that they have the same size ball end so they could be exchanged for the Escourt ones to give extra length . If any one can confirm this It would be apreciated
best wishes
Iain


Unfortunately not. I had the same idea and stripped down a Cortina rack only to find the track rods were pretty much exactly the same length.

niceperson709 - 22/2/05 at 10:39 PM

Thanks for the prompt answer guys
best wishes
Iain

Stu16v - 22/2/05 at 10:47 PM

quote:

They are internal the stress raiser and fatigue issue dosen't occur to anythng like the same extent


Purely of interest/learning: Why?

britishtrident - 23/2/05 at 08:53 AM

quote:
Originally posted by Stu16v
quote:

They are internal the stress raiser and fatigue issue dosen't occur to anythng like the same extent


Purely of interest/learning: Why?



Track rods are a bit of a problem because they are a slender column in compresion and it will want to buckle. With buckling the outer surface is subject to the most stress , and the weakest point on the outer surface is the sharp corner at the root of the thread.

This isn't a problem with the track rod end because te outer surface is a larger diameter.

Rolling the thread to a large alleviates the stress raiser and creates improved mechanical properties at the root of the tread.

Going back a few years I don't know if anybody on the list remembers the Africar project -- a CV2 based low technolgy cross country vehicle. The developers found that to to enable the ground clearance to be raised they had to introduce a very slight bend in the track rods -- this resulted in failures even in road use that no ammount modification and reinforcement was able to fix.

[Edited on 23/2/05 by britishtrident]

paulf - 23/2/05 at 10:31 AM

How about drilling and tapping the extension at each end and then screwing in a length of studding cut from a high tensile bolt or capscrew, to form the external thread.It could be locked in with locktite and a thin locknut.
Paul.

quote:
Originally posted by Stu16v
quote:

TBH I dont see the problem with cutting the threads as long as it is done properly. I know rolled threads are stronger, but is that extra strength needed here...?


Good question. The threads in the TRE's themselves are cut...

Northy - 23/2/05 at 06:21 PM

quote:
Originally posted by britishtrident
Sierra ones are longer


Do you happen to know roughly how much longer? Are they the same taper as Cortina and Escort ones?

Cheers

[Edited on 23/2/05 by Northy]

Stu16v - 23/2/05 at 06:53 PM

quote:
Originally posted by britishtrident
Track rods are a bit of a problem because they are a slender column in compresion and it will want to buckle. With buckling the outer surface is subject to the most stress , and the weakest point on the outer surface is the sharp corner at the root of the thread.

This isn't a problem with the track rod end because te outer surface is a larger diameter.

Rolling the thread to a large alleviates the stress raiser and creates improved mechanical properties at the root of the tread.


Ahh. I see, thanks for that. If only Whitworth threads were still in use...

I am guessing that you are picturing 'cut' threads overhanging, or protruding beyond the original TRE? I was picturing a male/female extension that would screw into the original TRE fully, using the 'shoulder' of the extension to butt against the TRE. This way the threads are only being used as threads IYSWIM, and not being put under tension/compression loadings (or at least, vastly reduced). Tracking adjustment would be by the original track rod being screwed in/out of the extension.

The weak spot would be the transiton of cut thread to shoulder, but that can be overcome with careful design...

[Edited on 23/2/05 by Stu16v]

ChrisS - 23/2/05 at 07:58 PM

quote:
Originally posted by craig1410
Here's a picture of my extensions in place.


Craig1410

Just wondered what type of rose joint you used for your steering column support, as i am using 19mm tube to extend it, i havent manged to find a rose joint with a 19mm eye.

Cheers.

[Edited on 23/2/05 by ChrisS]

craig1410 - 23/2/05 at 11:59 PM

Chris,
It's not 19mm, it is 16mm solid bar and the rod-end is an M16 female joint. I got it from a company called BSL Ltd in Irvine, Ayrshire. I think they were something like £16 each although I'm not certain.

I also got M16 bolts to suit the shank.

16mm solid bar seems to fit very snugly inside 19mm 16swg tube so I used the tube to join the bar where required.

I just used locktite to secure the steering shaft to the rod end inner bearing although it was already a tight mechanical fit.

HTH,
Craig.