Honda-SOHC

Other Stuff => Tricks & Tips => Topic started by: McCabe-Thiele (Ted) on October 11, 2022, 04:24:13 PM

Title: Easy way to remove the original type plastic rear swing arm bushes.
Post by: McCabe-Thiele (Ted) on October 11, 2022, 04:24:13 PM
Best if you are planning to re-paint the swing armn at the same time.

When I had my 400 swing arm powder coated I did not know that they were made of a plastic type material so left them in.
When the part came back I realised my mistake - I pushed my finger into the swing arm and they just pulled out really easily with my fore finger.

Today thought I would try to remove the same bushes on my 500 - I heated up the outside of the swing arm moving the flame of my plumbers torch as I did so to give a light all round heat of the swing arm where the bush is situated  - I then applied the heat to the outside flange of the bush with the flame licking inside it - as it started to burn on the outside I removed the heat - same for the other bush - & left it to go cold.

Poked my finger in the bush an hour later & out it came in one piece - no drama no tools.
Even the black swing arm powder coating still looks okay.
Title: Re: Easy way to remove the original type plastic rear swing arm bushes.
Post by: Johnny4428 on October 11, 2022, 06:00:04 PM
Nice one Ted. Whatever type of material it is it shrinks with heat. Is it Bekolite?
Title: Re: Easy way to remove the original type plastic rear swing arm bushes.
Post by: McCabe-Thiele (Ted) on October 11, 2022, 06:43:39 PM
I think Bakelite would be too brittle - I suspect it might be nylon based - it was used a lot in the auto industry. Only trouble with Nylon is it is slightly hygroscopic so used to jam when used as a bearing in domestic applications such as tin openers.
Title: Re: Easy way to remove the original type plastic rear swing arm bushes.
Post by: Oddjob on October 11, 2022, 08:09:06 PM
There are some problems with that Ted.

Firstly, if the swinging arm is still standard and has the standard paint on then using a flame will wreck it.

Secondly, the 500 doesn't have flanges on the swinging arm bushes, they are essentially just tubes of metal that sit inside the swinging arm, if you have flanged type bushes they ain't standard.
Title: Re: Easy way to remove the original type plastic rear swing arm bushes.
Post by: McCabe-Thiele (Ted) on October 11, 2022, 08:15:55 PM
There are some problems with that Ted.

Firstly, if the swinging arm is still standard and has the standard paint on then using a flame will wreck it.

Secondly, the 500 doesn't have flanges on the swinging arm bushes, they are essentially just tubes of metal that sit inside the swinging arm, if you have flanged type bushes they ain't standard.
My swing arm has been powder coated I think. I have no idea if the bushes are original or not. If you say the 500 s have metal I would not disagree. I would point out that replacement brass bushes all have the flange on the outside.

Either way Ken  the post is about how easy they are to remove with   heat! I did add the proviso about paint damage  at the start.
Title: Re: Easy way to remove the original type plastic rear swing arm bushes.
Post by: Nurse Julie on October 11, 2022, 08:35:19 PM
All the aftermarket bronze bushes you can buy for CB SOHC/4's, including the ones I sell, are flanged. When installing them, you don't refit the felt washer, or the outer plastic insert, you just fit the bronze bushes and the end cap.
Title: Re: Easy way to remove the original type plastic rear swing arm bushes.
Post by: Oddjob on October 11, 2022, 10:48:27 PM
The 550 used flanged bushes but they weren’t metal, they were some sort of hard nylon. It’s possible these may come out with heat Ted but the 500 metal bushes will laugh at heat, they are difficult to remove at the best of times plus as I said the flame would discolour the paint if not bubble it. Trust me Ted, been there, done that.

Without a special tool which goes behind the end of the bush and you can then drive the bush out from the other side the hacksaw method is the best way of removing them.
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