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Replacing Avo shock bushes
pmc_3 - 1/3/22 at 09:32 PM

I've got some new bushes from Merlin Motorsport for my Avo shocks. Anyone got any tips for fitting them? I've tried putting the bushes in boiling water to soften them up, washing up liquid. I tried pressing them in with a vice, I had it nice and square but the bush just distorted instead of pressing through.



[Edited on 1/3/22 by pmc_3]

[Edited on 1/3/22 by pmc_3]

westf27 - 1/3/22 at 11:45 PM

Threaded stud with thick washers and nuts.

nick205 - 2/3/22 at 10:01 AM

quote:
Originally posted by westf27
Threaded stud with thick washers and nuts.



That's the way I'd do it (and the way mechanics do tin top suspension bushes I believe).

Give the bushes a soaking in some warm water to soften them up first and something to lube them in.

Inteference fit cartridge bearings are generally done with hydraulic presses for the grunt, but it's the same principle.

pigeondave - 2/3/22 at 01:29 PM

Lube, lots of lube and a press

Burn the old ones out if you have to.

nick205 - 2/3/22 at 04:29 PM

quote:
Originally posted by pigeondave
Burn the old ones out if you have to.



Don't go buring them. Cut a section out with a junior hacksaw blade and they'll come out easy enough.

pmc_3 - 2/3/22 at 04:40 PM

The old ones were easy enough to get out, they had gone brittle.

This is all that happens if I try to use a nut bolt and penny washers to pull them in. And yes I know the bush needs somewhere to go, I was using a longer bolt and a socket, this is just for example.

2022-03 -02 15.58.36 by Pete Clayton, on Flickr

westf27 - 2/3/22 at 05:13 PM

How about this.Narrow banded jubilee clip around the middle section pushed up against the shoulder,wind clip to reduce bush diameter,insert into eye of damper.Similar to using a piston ring compressor.Infact option 2 could be with worm drive clip (others are available) over the shoulder ,wind clip and knock in bush or bolt,nuts and washers.
I guess the bushes are correct for the damper,have you checked diameters.

pmc_3 - 2/3/22 at 09:55 PM

Yeah the outer diameter of the middle of the bush matches the diameter of the hole in the shocks. I'm tempted to cut the bushes in half and put them in from either side, they'll be held tight when it's bolted up.

Dingz - 2/3/22 at 11:33 PM

Either that or make up a tapered bush (a bit like a wine cork inserter) to feed them into the eye.

indykid - 3/3/22 at 07:57 AM

You'd be better pressing it in with a vice or g clamp rather than using a bolt because you need the space in the centre to collapse the bush into.

It either wants squashing into a figure 8 shape and easing in or equally compressing with a tapered sleeve as Dingz said. If you were local, I'd knock you one up on the lathe but even a wood lathe should be capable of making one. If you've got a bit of pine, a drill, some files and a bit of time, you'll get there too.

motorcycle_mayhem - 3/3/22 at 07:16 PM

quote:
Originally posted by pmc_3
Yeah the outer diameter of the middle of the bush matches the diameter of the hole in the shocks. I'm tempted to cut the bushes in half and put them in from either side, they'll be held tight when it's bolted up.


That is the way I deal with the (way) harder PU and nylon bushes fit, two halves, slight gap in the middle, filled with silicone/PTFE grease, lovely.

From the pictures, these bushes look to be quite a lot softer, one helluva lot softer, than the ones I deal with. I'd errrr on trying to get them in whole, mechanical integrity and all that. As has been said, a hose clip (aka piston ring compressor) is probably the way I'd go. A few inches of a suitable diameter steel tube, split along it's length, closed up with a clip, and offered up to the bush snugly.

If you've got a sturdy funnel that's close (some of mine are stainless), there's a damn good ready made taper too.

pmc_3 - 3/3/22 at 08:31 PM

I got there in the end. I tried all the techniques on here and still had no luck.

I found I could get the end of the bush almost in to the eye at an angle by hand so in the end I lubed it up got it in as far as I could and then with a blunt tool poked the rest of the end of the bush in. Once it was in to that I could push it a bit further by hand and finished it in the vice with a socket. Once I’d done the first one the others only took about 10 minutes.

2022-03 -03 17.22.08 by Pete Clayton, on Flickr

2022-03 -03 17.22.48 by Pete Clayton, on Flickr