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Haynes Locost Bushings Size
geedle - 7/4/20 at 01:56 PM

Hi,

In the Haynes book (see image), it lists the ID and OD of the stainless bushings, but it doesn't give the length. I've made a couple of at 36mm (2 x the 18mm shown for each half of the bush). I think I'm missing something!

Anyone tell me what size the collar should be?

Thanks, Geedle.
[img]https://drive.google.com/open?id=1BzwnAdxSk2tBMoGs5MEwxg-ymCmBxCLk[/img]

jps - 7/4/20 at 02:04 PM

You've assumed the top hat bushes meet back to back - they don't!

The crush tube needs to be as long as the width of the tube your bushes go into, plus 2x the depth of the stepped section, plus a little bit (to avoid binding).

Alternatively you can consider they need to be the same length as the distance between the inside faces of the suspension bracket!

geedle - 7/4/20 at 02:28 PM

Yup - that's where I went wrong. So the inner tube should be clamped tight in the jaws of the bracket when the bolt goes through? Is that what I'm aiming for?

Thanks.

jps - 7/4/20 at 02:56 PM

quote:
Originally posted by geedle
Yup - that's where I went wrong. So the inner tube should be clamped tight in the jaws of the bracket when the bolt goes through? Is that what I'm aiming for?
Thanks.


Yes. The inner tube should be fixed, the bush should rotate around the crush tube. Some people find that the jaws of the bracket clamp the bushes and the wishbone itself is the only thing that moves, also not as intended. I don't have this problem (but if you fit it all dry then paint the chassis you might), but would think the easiest solution is just to sand the polybush down until it doesn't bind.

Although the Haynes book specs an M12 bolt, and a 12.5 hole, some people use 1/2 inch bolts and ream (not drill) the holes/crush tubes out to 1/2 inch. This will bring everything closer in tolerance than the book spec, but it is not essential.

On my build I did not do this for the wishbones, but I did choose to get shock absorbers with spherical bearings/rod ends (given the tolerances in alignment of the brackets). For these I reamed the brackets and used 1/2 inch bolts and spherical bearings/rod ends. Reaming the brackets in situ was a pain, doing it all again i'd do everything to 1/2 inch from the start (and use rod ends on the wishbones too).

geedle - 7/4/20 at 03:05 PM

That makes a lot of sense. My brackets are already on, but still good information. Much appreciated - thanks.

rusty nuts - 7/4/20 at 04:59 PM

Remember using wishbones with a narrower eye than the mounting brackets gives a small amount of castor adjustment using shims( I used stainless repair washers)

geedle - 7/4/20 at 05:58 PM

Had not considered that. How my under do I need to make the collars? A couple of mm?

Nickp - 8/4/20 at 04:53 AM

I put a thin stainless penny washer either side between the bush and bracket, reduces friction nicely when greased up

rusty nuts - 8/4/20 at 05:57 AM

My Luego has brackets approx 10mm wider than the arms.

geedle - 8/4/20 at 06:35 PM

That's quite a bit of adjustment. OK - thanks for that. Just as well I checked, otherwise I'd have been doing it twice!

geedle - 13/4/20 at 08:35 PM

I've been thinking (and reading) about this more. I was planning to build my wishbones with threaded adjusters as per the Saturn manual. That should give me the caster adjustment I need shouldn't it? Or am I missing something...