Series Gearbox Noise

Its been a long time since I last posted on the Series side of the site, but typicaly as I have been running my S1 88 over Xmas something had to go wrong.

The gearbox is making a rather bad noise in both 1st and Rev when you take your foot off the throttle, if throttle is on the box is good with no noise.

I think there is a shaft in common but its been a while, apart from the noise the box is great, no leaks, doesnt jump out etc. Its a S2 or S2a Box.

Is there any top tips for sorting this out. Are parts available to fix the fault??

bodgit0_0 said:

Its been a long time since I last posted on the Series side of the site, but typicaly as I have been running my S1 88 over Xmas something had to go wrong.

The gearbox is making a rather bad noise in both 1st and Rev when you take your foot off the throttle, if throttle is on the box is good with no noise.

I think there is a shaft in common but its been a while, apart from the noise the box is great, no leaks, doesnt jump out etc. Its a S2 or S2a Box.

Is there any top tips for sorting this out. Are parts available to fix the fault??

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The 1st layshaft gear is common to both 1st gear and reverse so I would suspect that the teeth are damaged on yours. As you're not getting the noise in 2nd and 3rd it's unlikely that it's caused by any of the bearings or the gearwheels which transfer drive from the primary shaft to the layshaft. Being a II/IIA gearbox, fortunately all the gearwheels are fitted to the layshaft by splines, whereas the SIII layshafts have a one piece design where the gearwheels are part of the shaft. I don't have a series II/IIA parts catalogue, so I can't be sure, but looking at John Craddock's website it seems that the gearwheel is part number 501616 (for gearbox suffix upto and including 'B') or 511189 (for gerbox suffix 'C' onwards). Either the gearbox or the engine will have to be removed to replace this gearwheel.