mainshaft swap out !

[bobber rob]

Hi guys, a technical question if any can help out ! I have an 88ish 5 speed softail tranny with the long mainshaft for belt final drive, is it possible to put the 91 up splined mainshaft in to my case to accommodate my new ultima 3" belt drive ?

any help greatly appreciated

rob

[hbmc]

are you asking if you can get rid of the keyed mainshaft and use a splined shaft in its place? Because you want to use a dry 3" primary drive? Of course you need a new clutch too. The hub needs to be splined as well. Length question? See 88ish and 91 5 speed compatibility or changes via google search 5speed schematic or your local dealer for difference in shaft length. Contact Ultima technical and they may know if there are any difference in lengths or diameter so your gear cluster will slide on it with the proper clearance.

[bobber rob]

Hi hbmc, thats exactly what I'm asking ! my mainshaft is the keyed type and I want to use the later splined type. I already have the ultima belt drive with the clutch with the splined centre .

[Dan89FLSTC]

If you are going to swap just the mainshaft in the transmission, and plan to keep all the original gears you must use a 1990 shaft, it will work with the earlier gearsets.

1991 and later mainshafts will not work with your gearset.

You would probably be better off finding a late model gearset that has been pulled out of a bike that was upgraded to a six speed, they are available on the well known auction site, you shouldn`t have to pay more than 150 bucks.

[hbmc]

Dan knows what he is stating Find a complete gear set. Or get a 6speed yourself. If you ride more then 60mph alot you will like it. Mine is still a 5speed and I am always looking for that 6th gear maybe I will tune down the cam to .625 lift as my bike just wants to rage all the time 70mph in 3rd with throttle room

[bobber rob]

Thanks for the heads up Dan, I see that Andrews (and probably others) do replacement mainshafts and if you say its the 1990 splined mainshaft thats a direct replacement for the earlier keyed shaft, then I think thats probably the cheapest way to go !
You guys have been a real help, thanks.
Rob

[Dan89FLSTC]

The Andrews shafts are about 200 bucks, which could get pretty expensive because you probably should replace all the seals and bearings while you have it apart.

I thought about going that route when I upgraded my `89 to the splined mainshaft, but realized it was much less expensive to go with a used late model gearset.

I installed a gearset from a `99 into my `89 case. My total cost was about 325 bucks.

That was the cost of the gearset ($150) and also all new bearings and seals ($175).

This is assuming the stock mainshaft is the correct length for your application, I have no epperience with belt drives, other than watching my buddy get his jeans caught in the belt at a red light, and down he went...