Hi All

just a word of warning to any one using an mx5 column.
the steering column has 2 collapsible parts the warning is about the bottom part.

the top part is on a double d design and continues to drive when collapsed no problem there.

the bottom part although I have not taken it apart seems to use a splined arrangement.
when collapsed the spline does not drive the steering

there fore when you use this column it could be nearly collapsed and only be driving on say 1 or 2 mm of spline
you hit a bump your chassis flexes a little or something moves while driving at speed and bingo !
no connection between steering and rack !!!!

please be aware I found this this when assembling my steering and was a little concerned especially if you don't realise you have installed your column in a partially collapsed state .

Be Alert , Britain needs Lerts.

[Edited on 11/6/18 by bart]

According to the exploded diagram in my MX5 workshop manual there is a pinch-bolt on that spline housing.
Providing the bolt is tight it will not allow the male shaft spline to part from its female steering rack mating surface.
Every other steering column I've ever come across has this or similar arrangement.
A bit of further investigation on your part is required.
HTH.
Cheers, Pewe10

This is the shaft that bolts onto the steering rack. Mine is now installed and I can't get at it to get a picture.there is no pinch bolt.only on the upper half. My guess is most people don't even know that this bit colapsess .as it looks like a solid shaft.I only found out cause I happened to drop in on the floor shaft end first. I will try to get pics when I strip it down

[Edited on 12/6/18 by bart]

quote:

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Originally posted by bart
This is the shaft that bolts onto the steering rack. Mine is now installed and I can't get at it to get a picture.there is no pinch bolt.only on the upper half. My guess is most people don't even know that this bit colapsess .as it looks like a solid shaft.I only found out cause I happened to drop in on the floor shaft end first. I will try to get pics when I strip it down

[Edited on 12/6/18 by bart]

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Mk 2 anything else unknown was ebay job

I have some pics will post later

Ok had a look at mk1 pics and the lower steering column looks the same as a mk2.
Hense my warning.believe me what looks like a solid rod where it reduces in diameter is colapsing it has an o ring where it reduces to make a seal. Don't believe me take a closer look you have been warned .

I'm changing an engine in a Mk2.5 at the moment so was able to take these pics.

The second is a close up of the bottom u/j splines.


Hope this helps.
Paul G



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Yep 2.5 is the same.
I have marked up some pics to point to the area

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ok found this on interweb

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ok top ( large diameter ) collapse is ok as it is a dd design and continues to drive

the smaller collapse is a serrated shaft and socket design and if fully collapsed will disengage the drive


as I say my worry is that folks may not realise this and if installed say nearly collapsed then you could be mm away from

&^%&^$"£% disaster . nuff said .


have a good day folks


ps from interweb pics this is mk1 - 2- 2.5 - 3 - 4

There must be a differant type of column MX5 mk1 I have one on my roadster and two spares and they are all welded on the lower joint, i guess you learn something new every day!

[img]https://i.imgur.com/8BjKyCy.jpg?2[/img]
https://imgur.com/8BjKyCy


[Edited on 13/6/18 by Charlie C]