Merits, or otherwise, of the widetrack 8mm front upright spacer.

[naddy]

I’ve stripped down my front suspension for some cosmetic tidying and discovered that I have no spacer between the lower wishbone spherical joint and the bottom of the upright on either side of the car. I also have a regular lock nut that doesn’t appear to be the ‘turned down’ version. 

The build manual says widetrack should have the spacer and the special nylock.

searching BC on this topic and the prevailing opinion seems to be aligned with the build manual but a couple of references to running without the spacer, and one refers to having a larger spacer...

https://www.lotus7.club/forum/techtalk/widetrack-8mm-upright-spacer suggests that Gary May advised leaving it off

https://www.lotus7.club/forum/techtalk/what-upright-nut-used  #5 suggests the arrangement that I have  

and this one refers to Gary May advocating a 10mm spacer! https://www.lotus7.club/forum/techtalk/front-suspension-question-0

 

has anyone an opinion on this? I’m inclined to put it back as I’ve found it but I’d like to be making a more informed choice.  It’s apparently been ‘wrong’ for some time on my car but I have not had a problems.  Car is year 2000 superlight, widetrack.

 

 

 

[naddy]

[ChrisC]

Can't help with your question, but I can say I thought they where added to allow full movement of the spherical bearing in the wishbone, but I could be wrong. 

I though I would post because the cut down nut has been superseded with a Top Hat spacer and 1/2 nut. 

You can see the new design here

https://caterham420detailedbuildblog.co.uk/2019/11/17/uprights/

 

[Wrightpayne]

I think the later vertical links have a longer threaded portion on them.

[Paul Richards]

I think the reason for a spacer or special nut was that on full droop there was potential for a corner of the nut to make contact with the wishbone and if the steering is then turned it could undue the nut. When I upgraded to widetrack I found the nut did indeed touch on full droop. I therefore fitted a small spacer and used a normal nylock (making sure the thread protruded sufficiently though the nut). As you know Nick my car is a similar age to yours. My suggestion would be rebuild as it is already but use a new nylock nut and make sure there is no contact with the wishbone on full droop. Also make sure that the thread of the upright protrudes sufficiently through the nylock.

[7 wonders of the world]

Removed on the instructions of Gay May when I fitted Freestyle inboard suspension, it does limit contact with the spherical bearing but also influences the lower wishbone geometry too

[naddy]

Excellent, thanks.

#3 I though I would post because the cut down nut has been superseded with a Top Hat spacer and 1/2 nut. 

#4 I think the later vertical links have a longer threaded portion on them.

#5 I think the reason for a spacer or special nut was that on full droop there was potential for a corner of the nut to make contact with the wishbone and if the steering is then turned it could undue the nut.

#6 Removed on the instructions of Gay May when I fitted Freestyle inboard suspension, it does limit contact with the spherical bearing but also influences the lower wishbone geometry too

I'm surmising that:

1. Possibly, early widetrack was fitted at a time when there was a shorter threaded portion on the bottom of the upright and so the cut down nut was needed so that the nylon bit would engage, unless the spacer was omitted above the bearing in which case there would be plenty of thread anyway
2. my car has an upright with a longer threaded portion (based on #4) so engaging the nylon bit wouldn't be such a problem but the cut down nut has the benefit of fitting inside the bearing; The smooth portion of the upright that locates in the bearing is about 18mm long and the bearing is about 19mm long so if you fit a 8mm spacer above the bearing then the 4mm long turned-down bit of the special nut can locate in the bearing and occupy some of the 'gap' created by the upper spacer (would this matter?).
3. some time post-2000 (based on #3) the turned-down nut got replaced by a top hat which located in the bottom of the bearing and a normal (but shallow) nut was used because I guess the top hat was easier/cheaper to make than a fancy nylock?
4. moving the nut down is a very good thing!! (based on #5) because it might unfasten . The special nut is the same size across flats as the std one but I've only just noticed has an extra 2mm portion that wouldn't engage in the bearing and would keep the hexagons lower. cunning.

 Can I just check:

Paul, you fitted a spacer below the bearing (essentially in lieu of the later-supplied top hat)? and do you have the upper spacer fitted?

7WOTW, are you referring to the upper spacer? is it the case the the upright might foul the upper side of the wishbone?

Maybe I'm missing something but I'm not understanding why the upper spacer was mandated in the first place? clearance issues or geometry? If it becomes a question of geometry then I'll get confused! but if Gary advocated getting rid then I'd be swayed by that 

[naddy]

New nut from Redline, I hadn’t looked closely at it when I posted last night, nor did I realise my car didn’t already use them!

[Wrightpayne]

Paul,

Did you make a sleeve to go in between the spherical bearing and vertical link? On older vertical links the 8mm spacer pushes the spherical bearing off the end of the turned portion at the bottom, hence the turned down nyloc was introduced to fill that space.

Regards

Ian

[Bricol]

Just reading the text in that diary - surely it really means cooling the spacer so it "shrinks" not "expands" . . . ;)

And not all metric nylocs have blue nylon inserts, not all imperial have white - you can have white, yellow, blue even red black in any thread - a manufacturers preference/choice it seems.

[ChrisC]

Yes, my mistake it should be shrinks

As for the inserts, I must admit to never seeing any other colour combination other than blue metric and white imperial, and that certainly is the case for the current fixings provided by Caterham, but a simple tweak to the wording will be made.