Theshed
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posted on 2/12/20 at 10:52 PM |
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I may be wrong ...and often am... but I think the conventional taper measurements are inches per foot in old money and not degrees etc. Mot sure if
there are more modern standards
A rough translation of the measurements given is 0.25 " per foot
Might give another way of reverse engineering this.
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Replicar328
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posted on 3/12/20 at 01:28 PM |
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Many thanks David. They are indeed not cheap! I guess this is a last resort, I will re-double my efforts to find a tie rod end with the correct
taper. I'm even thinking of designing a wishbone into which the Mazda top joint can be pressed although I'm concerned that it's
only a tight press fit. I wonder if anyone has tried doing this...
Cheers
Adrian
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Replicar328
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posted on 3/12/20 at 01:33 PM |
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Thanks "TheShed" - I suspect I am wrong more often! In this case you are probably right
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geedle
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posted on 15/12/20 at 10:02 PM |
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Those are rather pricey, but it may be the solution.
My cheap eBay track rod end arrived (eventually!). Ridex part number 914T0184 (but a cheap pattern version of it). The taper seems to be right.
When fitted snugly, the threads protrude 13mm through, so it is possible to get it good and tight. However, the upright is 18mm thick where the track
rod goes through. I reckon that 11mm of the pin is in contact with the upright. The conical part of the pin certainly can't protrude from the
hole in the upright, because if it did, it would not be possible to pull the pin in tight with the nut, but I reckon it should be a couple of mm shy
rather than 7 or 8mm.
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jps
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posted on 17/12/20 at 06:32 PM |
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I am not familiar with the MX5 uprights, so this might be a nonstarter. But is there not an option for you to drill out the tapered hole so it's
no longer tapered - put a bolt through and use a rose joint instead of a track rod end?
I was at AB Performance recently and Andy Bates suggested I do this to replace the tapered fitting track rod end on my Sierra hub/Escort steering rack
setup. In my case it was to enable bump steer to be adjusted more easily than shimming the rack, but could you apply the same solution in your case?
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PorkChop
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posted on 20/12/20 at 05:52 PM |
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quote: Originally posted by geedle
Those are rather pricey, but it may be the solution.
My cheap eBay track rod end arrived (eventually!). Ridex part number 914T0184 (but a cheap pattern version of it). The taper seems to be right.
When fitted snugly, the threads protrude 13mm through, so it is possible to get it good and tight. However, the upright is 18mm thick where the track
rod goes through. I reckon that 11mm of the pin is in contact with the upright. The conical part of the pin certainly can't protrude from the
hole in the upright, because if it did, it would not be possible to pull the pin in tight with the nut, but I reckon it should be a couple of mm shy
rather than 7 or 8mm.
Which is basically what I found. It fits, you can tighten it but the threaded length is really a bit too short to have a secure fixing. And definitely
way too short if you want to put a secondary fixing like a split pin.
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PorkChop
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posted on 20/12/20 at 06:18 PM |
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quote: Originally posted by jps
I am not familiar with the MX5 uprights, so this might be a nonstarter. But is there not an option for you to drill out the tapered hole so it's
no longer tapered - put a bolt through and use a rose joint instead of a track rod end?
I was at AB Performance recently and Andy Bates suggested I do this to replace the tapered fitting track rod end on my Sierra hub/Escort steering rack
setup. In my case it was to enable bump steer to be adjusted more easily than shimming the rack, but could you apply the same solution in your case?
The issue you have is that you can create stress raisers where the bolt / nut clamps against the upright. With a tapered fitting the load is
transferred more evenly.
What I designed to use on my car was along the lines you suggested though, and used a M14 x 1.5 rose joint to fit to the wishbone. I just kept the
tapered fitting.
It might be worth dropping Callan Trump of T89 Designs a line - he offered custom pin kits at one time...
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nick205
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posted on 21/12/20 at 04:07 PM |
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Correct me if I'm wrong, but aren't they Ford Transit Mk2 "Drag Links" NOT Track rod Ends.
I think if you check you'll find there's a difference in the design between Drag Links and Trad Rod Ends.
To expand, I think Drag Links generally have a male thread and Track Rod Ends have a female thread.
Drag Link
Track Rod End
[Edited on 21/12/20 by nick205]
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PorkChop
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posted on 21/12/20 at 04:27 PM |
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quote: Originally posted by nick205
Correct me if I'm wrong, but aren't they Ford Transit Mk2 "Drag Links" NOT Track rod Ends. I think if you check you'll
find there's a difference in the design between Drag Links and Trad Rod Ends.
You're right and wrong.
M18 drag links for the Sierra version.
M14 BMW track rod ends for the MX-5 version (originally Saturn Sports Cars' suggestion, which as far as I've seen the vast majority have
followed).
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nick205
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posted on 21/12/20 at 04:37 PM |
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quote: Originally posted by PorkChop
quote: Originally posted by nick205
Correct me if I'm wrong, but aren't they Ford Transit Mk2 "Drag Links" NOT Track rod Ends. I think if you check you'll
find there's a difference in the design between Drag Links and Trad Rod Ends.
You're right and wrong.
M18 drag links for the Sierra version.
M14 BMW track rod ends for the MX-5 version (originally Saturn Sports Cars' suggestion, which as far as I've seen the vast majority have
followed).
Happily corrected.
I built a Sierra based MK Indy so it makes sense. IIRC I used the M18 Drag Link on the front upper wishbones and MK supplied the M18 plain nuts for
them.
[Edited on 21/12/20 by nick205]
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geedle
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posted on 21/12/20 at 06:16 PM |
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I found that there was enough thread by a long way, but the lack on cone contact area is a bit worrying.
[Edited on 21/12/20 by geedle]
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Deckman001
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posted on 21/12/20 at 06:35 PM |
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I need to get thinner nuts for my top ball joints, does anyone know what the thread is at the end of the taper after it has gone through the upright
?
I cut my nylocks down, but wasn't able to keep the nylock end so have to try again
Jason
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PorkChop
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posted on 21/12/20 at 06:43 PM |
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quote: Originally posted by geedle
I found that there was enough thread by a long way, but the lack on cone contact area is a bit worrying.
[Edited on 21/12/20 by geedle]
Because the BMW track rod end was originally specified for the mk1 / NA MX5 upright by Andy at SSC.
The NB upright is different in that the thickness of the NB upright where the track rod end fits is significantly more than the NA version
(this is the 6mm dimension I've mentioned earlier).
Therefore the tapered length is longer on the NB.
As far as I could measure, the taper angle is the same on NA and NB.
Whilst there is enough of a threaded section, because the tapered section is too short, the whole thing is too short IME (which I may or may not have
been clear enough about before). My going in point on this was that if there was deemed to be enough contact for the TRE and the NA upright, then that
was the second thing to look at after finding an alternative TRE that gave me the overall length I needed in the NB upright, which I failed to do. In
other words, my concern wasn't just with the amount of contact between the TRE taper and the upright's taper.
I spent a significant amount of time trying to find a M14 x 1.5 TRE that had a longer taper, but still had the same angle. I found nothing suitable
hence designing my own.
Can you fit the track rod end into your upright and still have threads protruding beyond the nyloc geedle?
[Edited on 21/12/20 by PorkChop]
[Edited on 21/12/20 by PorkChop]
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PorkChop
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posted on 21/12/20 at 06:49 PM |
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quote: Originally posted by Deckman001
I need to get thinner nuts for my top ball joints, does anyone know what the thread is at the end of the taper after it has gone through the upright
?
I cut my nylocks down, but wasn't able to keep the nylock end so have to try again
Jason
Would the IVA man be happy seeing just a plain nut on a critical suspension fixing?
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geedle
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posted on 21/12/20 at 09:36 PM |
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I removed the rubber boot to make the photos clearer. Remember this is the cheap nasty eBay one, so it could have longer threads on it.
Pressed in as far as it will go - lots of cone still showing. Does not seem to rock though, which would indicate correct taper:
TRE1
Showing taper still exposed:
TRE2
If anything, I think the code may be too long. If the cone is longer than the thing it is going through, it won't be possible to use the nut to
tighten it such that it won't work loose:
TRE3
Edit: I've put links in to some images on Google drive. I can't get the photo archive to work.
[Edited on 21/12/20 by geedle]
[Edited on 21/12/20 by geedle]
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jps
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posted on 22/12/20 at 10:40 AM |
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quote: Originally posted by geedle
It is not here yet. Maybe the best bet is to put it in with some engineers blue and have a look at the contact patch...
Have you done this? I'd be wary of going on feel alone...
I still think the best solution for you here is to machine a fitting. Given what Porkchop said about the need for a taper to distribute forces - ream
out the fitting to a known taper - machine a tapered pin to fit the upright - and use a rose joint to connect the pin to the upper wishbone.
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