Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: Crispy on February 22, 2018, 05:28:15 PM

Title: swingarm stuff
Post by: Crispy on February 22, 2018, 05:28:15 PM
hi all,
hasn't taken long for me to ask my first question!
on stripping down my K1 swing arm I discovered it was damaged and ordered a replacement. It was upon examining the replacement that I realised that the collar ( part 12) was missing entirely from the original swing arm, no wonder it was damaged!  The replacement looks identical but the original pivot pin (15) will not fit through the collar,  according to the parts manual these parts are common to the K0,K1 & K2..it would be nice to know what am I missing here before I shell out on a new collar. Can anyone enlighten me?
Title: Re: swingarm stuff
Post by: Nurse Julie on February 22, 2018, 05:38:56 PM
Has either your original swing arm or the replacement got needle roller bearings fitted instead of standard bushes?
Title: Re: swingarm stuff
Post by: Crispy on February 22, 2018, 05:52:06 PM
No..both got the standard parts apart from the original missing the collar.
Title: Re: swingarm stuff
Post by: r1_pete on February 22, 2018, 09:12:00 PM
I thought all sohc were 14mm spindles, the dohc went to 16mm, I have modified a dohc to fit my K1, it uses needle rollers, was wider and longer than the K.
Title: Re: swingarm stuff
Post by: philward on February 22, 2018, 10:15:43 PM
Mic the original spindle - o check if its not rusted, corroded and hence oversize - might have been damaged due to missing spacer. Conversely, check the bushes in the replacement swingarm in case they've been damaged - sounds obvious but got to be one or the other.
Title: Re: swingarm stuff
Post by: Crispy on February 22, 2018, 10:49:17 PM
Mic the original spindle - o check if its not rusted, corroded and hence oversize - might have been damaged due to missing spacer. Conversely, check the bushes in the replacement swingarm in case they've been damaged - sounds obvious but got to be one or the other.

Cheers...will do that tomorrow..I don't suppose it would take much of a blemish to cause a problem.
Title: Re: swingarm stuff
Post by: Bryanj on February 23, 2018, 06:43:44 AM
What you are calling a pivot is only a bolt, the collar is trapped in the frame by tightening the bolt and so does not turn--the bushes turn on it, i dont think the diameter or length of the collar varies accross all the 750 but the grease holes and spirals(or lack of) do
Title: Re: swingarm stuff
Post by: Crispy on February 26, 2018, 08:45:45 PM
Well I measured the internal diameter of the collar 13.92mm and the external diameter of the Pivot Bolt 13.93 ..(an average of 4 measurements each) so I guess it's pretty close...there must be a bit of corrosion or other distortion somewhere...I'll  just get a new collar when I get round to reassembly and see if it fits then.
Pleased to have got the old bushes out without any hassle after following the tips picked up on this forum... thought that would be harder than it was ..thanks!  :)
Title: Re: swingarm stuff
Post by: kettle738 on February 28, 2018, 01:20:00 PM

Could your pivot bolt have had a fresh coat of bright zinc plating and 'grown' enough to prevent it getting inside the collar?

Every time I have spindles or the like zinc plated it's usually necessary to remove it from close fit areas.

Just a thought............Mick.
Title: Re: swingarm stuff
Post by: Crispy on February 28, 2018, 02:20:01 PM
Hi,
Yes that is a distinct possibility..it does look quite 'shiny'! That would also explain why the original collar was left out!  Bit drastic tho...it's getting me a bit worried about what else that owner did..especially regarding the motor!  :-\
Title: Re: swingarm stuff
Post by: AshimotoK0 on February 28, 2018, 04:46:17 PM

Could your pivot bolt have had a fresh coat of bright zinc plating and 'grown' enough to prevent it getting inside the collar?

Every time I have spindles or the like zinc plated it's usually necessary to remove it from close fit areas.

Just a thought............Mick.

Why not get a quote from Phillpots to hard chrome & grind to size as already suggested I think.
Title: Re: swingarm stuff
Post by: Crispy on February 28, 2018, 05:03:33 PM
I think that is what I will possibly end up doing, will check it on a new collar first but I am sending my fork top tubes there so could send it with them.
Title: Re: swingarm stuff
Post by: Crispy on March 16, 2018, 10:54:56 PM
Update on this...I Paid a visit to David Silvers while in the area and got hold of a new collar... The pivot bolt fits through this one .....looks identical to the old one but obviously isn't...anyway problem sorted now thanks!   :)
Title: Re: swingarm stuff
Post by: Bryanj on March 16, 2018, 11:29:55 PM
I will put money on a previous owner trying to beat out a siezed collar with a big bolt and putting a burr on the inner edge
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