replacing gearbox on 1986 r45

[james_kiernan]

hi folks first time on here an am looking for advice.I have recently done a lot of work on my 1986 r45 but now I am finding it difucult to get her into 1st gear and also when in neutral it sounds like it is trying to get into gear. I  not been able to locate a gearbox (without having to take out a bankloan),but have been told that the gearbox from a r65 would do the job.can anybody confirm this for me and if so what price would I expect to pay.

[Bob_Roller]

Before I would consider a replacement transmission, or a rebuild, I would remove the transmission from the bike, clean and lubricate the transmission input splines .

Also clean and lube the throw-out bearing at the back of the transmission .

Maybe also clean lubricate and properly adjust the clutch cable .

Another weak spot is the rubber boot that goes over the speedometer drive cable where it enters the transmission .

The boot loses it's grip and sealing capabilities and water gets into the transmission, the result is a creamy/brown look to the gear oil .

Let this go too long and there's a good possibility of rust damage to the ball bearings in the transmission .

[Barry]

Yes an R65 gearbox or any Airhead gearbox form 1981 onwards will fit. I agree with Bob though that you should check out all the other possibilities first.  A second hand box from an unknown source could be risky as there are some problems to be aware of like a missing circlip in 84/85 boxes and selector springs breaking.

Have you tried people like Motorworks and Motobins for prices on a 2nd hand box or overhaul of yours.

[james_kiernan]

thanks lads will strip it down and look out for any damage ,ive tried motobins but the best price is 350 plus .ive already put about 600 into her so ive pushed the boat out abit.new exhausts,clutch,tyres,battery and wind shield ,hope its not goin to be a replacement gearbox maybe just something i can sort out myself.