Neil Fletcher Racing

Mexico ARB Bracket

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Shortly after buying my first Mk1 RS Escort back in the early 1980’s, I discovered that there were differences in the Anti Roll Bars that were fitted to the RS range when compared with the standard cars. One of the most noticeable differences being the length from the front cross piece of the bar back to were it mounts in the Track Control Arm, The Twincam/Mexico style bar is about ¾” shorter than the standard one.

A guy who had been around Mk1’s for much longer than I, told me that this was because RS’s were fitted with 13” wheels as opposed to the 12” wheels on a standard car. The shorter bar was needed to pull the larger wheel and tyre forward so that they wouldn’t foul or catch on the back edge of the wing or the area of the front footwells. It sounded a reasonable enough reason - and in my innocence I believed him!

Sometime later I discovered for myself that the reason he had given was wrong (I’m trying to be diplomatic here). Yes the rearward arms of the bar were shorter but the mounting point was moved further back on the mounting bracket which to the best of my knowledge left the wheel only very little further forward, this had the effect of a very slight increase in castor – or the self centring effect of the steering as it is known. I think the reason for the shorter arms was to increase the effective stiffness of the bar.

All of this means that if you are using a standard bar, you must use the standard bracket and if you are using the Twincam/Mexico style bar then you must use the mounting brackets that go with that bar. If you mix these items up you will end up with your steering angles all wrong and a seriously miss-handling car.

That’s all well and good, but what if you have a Twincam/Mexico anti roll bar but cant find the proper mounts to go with it – well the answer is quite simple, do what Ford did, they didn’t make one specially for the Twincam/Mexico etc, they just took standard mounts and modified them. Now read on for more detailed info on how you can do this yourself.

Click on any of the images below for a larger photo.

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The first thing you need to do is identify what bar you have. If you have both types you can stand them up vertically like this and compare them.

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The Twincam/Mexico style one will be the shorter of the two.

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Of course that’s not much use if you only have one bar. In this case you need to measure it. Firstly the quick method :- stand it up as above and measure from the ground up – as below.

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The measurement up to the top edge of the bar should be about XX inches for the Twincam/Mexico one and about XX inches for the standard one. This method doesn’t really allow for any differences there may be in the length of the lathed down and threaded area at the back of each arm where the TCA mounts.

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A more accurate way is to measure to this shoulder that the TCA abuts to. Different makers will have slight differences in their bars. First tie a piece of string on like this.

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Then tie it across to the other shoulder on the other side like so.

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Now measure from the back edge of the bar like this.

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Back to the piece of string. For a Twincam/Mexico bar you should get a measurement of XX inches and for the standard bar it should be XX inches.

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Another thing that you can do for your own satisfaction is to measure each arm and check they are both the same. Measure at each side just at the start of the rearward bend.

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The measurements should be the same or very close. I remember buying a new bar from a major supplier a few years ago – when I did this little check there was over a ¼” difference in the two sides. Needless to say I took it back and got another better one.
arb_2.jpg (28288 bytes) Now on to the anti roll bar mounts themselves. On the right we have the standard roll bar mount and on the left a Mexico one - it just happens to be a brand new one from my stock of spares, notice the sticker. Notice how the mounting holes etc are much further back on the Mexico one. If you look very closely at the Mexico one you can still see the original holes in it. These are both lefthand/nearside mounts in this photo.
arb.jpg (42465 bytes) Now for the bottom side, once again the Mexico one is on the left.  This also shows just how far “back” and “out” that these were moved by Ford. Now you also know why I said Ford didn’t make a special one but just modified a standard one.
arb_3.jpg (27673 bytes) If you are going to do this same conversion, then the first thing to do is remove the bottom plate. OK lets take the standard one and drill out the six spot welds which I have highlighted in this photo.
arb_4.jpg (22658 bytes) It doesn’t really matter if you just drill out enough to remove this lower plate – or if you drill right through both plates. In actual fact its probably best to drill right through as you will then use these holes to spot weld on a new lower plate. Note - don't drill right throught the front two holes as you'll only have to fill them up later.
arb_5.jpg (39817 bytes) If you do this carefully you will now be able to lift away the undamaged lower plate. It may need a little persuasion to come free but try not to damage it as we will be re-using it later on.
arb_6.jpg (51112 bytes) Now turn the mount over and remove the two captive nuts. A good whack with a hammer or a cold chisel should be enough to break the welds without damaging the nuts. You might want to keep these as well for later use. Alternatively you can get new ones if you want to.
Olympus Photos 2010 455.JPG (158899 bytes) Next job is to get some steel to make the new bottom plate, 2mm thick steel is ideal and for a pair of brackets you'll need two bits 56mm by 120mm approx.
Olympus Photos 2012 010.JPG (85533 bytes) Here I've blasted and etch primer both the original standard mount that I'm working on and the new bottom plate. As you can see it now turns out that I shouldn't have drilled right through the two front holes. The new plate should sit back against the little folded over part at the rear and should also line up with the inner/engine bay side of the original bracket - note this means that it actually sits out past the other chassis rail side just as per original Mexico/Twin Cam ones.
Olympus Photos 2012 014.JPG (108066 bytes) While I had the new bottom plate in position I marked the front edge of it so I could drill two new front spot weld holes - they are just behind the two original ones. I have also opened up the other four holes.
Olympus Photos 2012 016.JPG (100312 bytes) Next thing is to weld up those two unused original front spot weld holes.
Olympus Photos 2012 025.JPG (68871 bytes) Then with the new bottom plate held in position with a pair of vice grips I can start to weld the plate in position by filling up those other six holes with welds.
Olympus Photos 2012 030.JPG (137372 bytes) And now I have all six plug/spot welds finished off and ready for grinding off flush. At this stage I realize that it might have been better to drill and plug weld the new plate rather than the original bit - it would have left it easier to grind do the excess weld.
Olympus Photos 2012 028.JPG (139545 bytes) And from below you can just make out where the spot welds are.
Olympus Photos 2012 027.JPG (77771 bytes) Here you see the way that the new bottom plate just overlaps the chassis rail edge of the bracket by about 3mm or so.
Olympus Photos 2012 029.JPG (85574 bytes) Another thing you may notice is the way that the new bottom plate doesn't sit quite square/flush with that little folded over rear piece. I've looked at a couple of originals and most seem to be like this so it doesn't really matter.

More details to follow soon.

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