Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: Bro550F on July 21, 2022, 11:27:36 AM

Title: CB550F2 1978 Gears
Post by: Bro550F on July 21, 2022, 11:27:36 AM: After riding and the engine/gearbox are hot, I've noticed the gears are harder to engage and quite often get a missed gear between 1-2 and 3-4.

Could this be due to selector forks or worn dogs on gears, or clutch possibly.

Any ideas ??
Title: Re: CB550F2 1978 Gears
Post by: Bryanj on July 21, 2022, 11:30:08 AM: How old and what type of oil you using?
Title: Re: CB550F2 1978 Gears
Post by: Bro550F on July 21, 2022, 04:33:06 PM: Oil and filter are about 200miles old.

10-40 Mineral I think......
Title: Re: CB550F2 1978 Gears
Post by: Bryanj on July 21, 2022, 05:28:27 PM: Depends on the exact spec of the oil, diesel 10w40 is better than petrol 10w40
Title: Re: CB550F2 1978 Gears
Post by: Bro550F on July 21, 2022, 06:54:50 PM: Quote from: Bryanj on July 21, 2022, 05:28:27 PM
Depends on the exact spec of the oil, diesel 10w40 is better than petrol 10w40

I'll check when I go into garage tomorrow, seem to recall it could be diesel 10W40.

Is this a common trait? Don't recall my original in 1976 giving issues !!
Title: Re: CB550F2 1978 Gears
Post by: Oddjob on July 21, 2022, 09:40:36 PM: Suspect clutch more than gears TBH. Especially if it's related to heat.
Title: Re: CB550F2 1978 Gears
Post by: Bro550F on July 22, 2022, 08:27:38 AM: Quote from: Oddjob on July 21, 2022, 09:40:36 PM
Suspect clutch more than gears TBH. Especially if it's related to heat.
Will check the clutch adjustment at both ends.

It seems smooth and light.
Title: Re: CB550F2 1978 Gears
Post by: Bryanj on July 22, 2022, 08:47:02 AM: Thats why i asked what oil, gearboxes on the 550 are pretty robust, i have heard of ,but not seen, of odd gears breaking dogs off but that dont give false neutrals
Title: Re: CB550F2 1978 Gears
Post by: Bro550F on July 22, 2022, 05:21:32 PM: Quote from: Bryanj on July 22, 2022, 08:47:02 AM
Thats why i asked what oil, gearboxes on the 550 are pretty robust, i have heard of ,but not seen, of odd gears breaking dogs off but that dont give false neutrals
Good to know, thanks. 👍
Title: Re: CB550F2 1978 Gears
Post by: Oddjob on July 22, 2022, 05:23:20 PM: It could be the cork parts of the friction discs are swelling with the heat. Could be they are getting real old and this is causing them to swell.
Title: Re: CB550F2 1978 Gears
Post by: Bro550F on July 25, 2022, 08:58:00 AM: Quote from: Oddjob on July 22, 2022, 05:23:20 PM
It could be the cork parts of the friction discs are swelling with the heat. Could be they are getting real old and this is causing them to swell.

Cheers, will prob wait for winter to strip down.
Title: Re: CB550F2 1978 Gears
Post by: Trigger on July 25, 2022, 10:19:46 AM: Quote from: Bryanj on July 22, 2022, 08:47:02 AM
Thats why i asked what oil, gearboxes on the 550 are pretty robust, i have heard of ,but not seen, of odd gears breaking dogs off but that dont give false neutrals

Seen a few dogs broken off, when a 550 engine has been rebuilt and the retaining plate that hold the dog shaft in has been put in the wrong way. Always worth checking this as, the beveled edge of the plate goes to towards the engine. If this is not fitted correctly, the gear box will lock up very soon. ;)