1150 transmission in 1100E engine

[Katmandoo]

Hey all. I searched around the forum to see whether anyone else has gone this route but was unable to come across anything. If I missed it and am double posting, my apologies. So here goes.

I just got hold of a pristine transmission from an 84 1150 EFE. I got it because my existing gearbox has several gears that are really in poor shape and an 1100 gearbox was nowhere to be found online. I was careful to cross check all the part numbers for the gears and despite some numbers not matching for the most part it looked like it might just work.

I found only 4 things that are different on the 1150 tranny.  First off the roller bearing on the drive shaft just behind the chain sprocket is 25 x 62 x 19 where-as on the 1100 it's 17. The drive shaft is also several mm longer but that's at the threaded end. The countershaft is also longer by approx 5mm but that's also at the thread. Furthermore when I looked at the end of the countershaft from the clutch side I noticed an aluminum plug with a small hole down the middle that air passes freely through. I'm guessing this is for lubrication. Other than these differences it would appear that this tranny will work fine. I did a dry mock up in my 1100E casings, swapped the 19mm deep bearing for a 17 and dropped the complete unit in place. I installed my crankshaft and clutch assembly and checked that everything rotated fine and that I could change gear. No problems discovered. So based on this I think I'm going to go ahead and keep things the way they are. I didn't see any issues with the longer threads on either the countershaft or the drive shaft. The only thing that leaves me with a question mark is that aluminum plug. The original 1100E countershaft is closed at the end. Is there anything I should be concerned about regarding this plug..? Does anyone know why Suzuki would have incorporated this in the 1150 shaft and not the 1100..? Am I ok to leave it as is or should I close it off..?

Hope someone might be able to help out.  Thanks in advance.

[Isleoman]

   It's definitely doable using 1150 trans in 1100.   I've seen it discussed multiple times on the Girls Blouse site, but I don't remember what steps are required to make it happen.  

If you're a member there (GS Resources) you can do a quick search.  I don't go there any more or I'd look it up for you.  

[Katmandoo]

Thank you Isleoman. Yes I am a member of the GS Resources (just recently) and there is a bucket load of information regarding these older machines. Actually a really good site for those wanting to maintain their bikes. Well worth registering. Lots of info regarding the 1150 tranny in the 1100 engine but I couldn't find anything about that plug. Maybe it's of no consequence in the grand scheme of the Suzuki design engineers mind and maybe I'm just over thinking things, but I'm curious that's all.  Don't want to have to make another post about a blown 1150 tranny only to have a site member go...."Oh, you should've blocked off that aluminum plug...bla bla bla"

Edited January 29, 2021 by Katmandoo

[Arttu]

If I understood correctly that plug with hole basically bleeds oil inside the clutch?

I have played with both 1100 and 1150 transmissions but haven't ever compared the parts against each other in details. However, the lubrication circuit is basically the same on both engines so 1150 transmission shafts in 1100 engines shouldn't do any harm. I guess this hole is added to get a bit more oil in the clutch hoping to improve its behavior. It seems that Suzuki has done quite many this kind fine adjustments for clutch oil control over the years.

[Katmandoo]

Thanks Arttu,

That's kinda what I thought too, but I'm loathe to just accept something without at least making an effort to understand why something is done the way it is. Your explanation makes sense, and if you have already used 1150 trannies in 1100 engines without ill effect then I'll put my faith in your experience and just go with it.

[Arttu]

Actually I haven't used a 1150 transmission with 1100 cases, only with 1150 cases. But based on pretty good understanding of lubrication system of these engines I would say it shouldn't make any difference if a 1150 tranny is placed in 1150 or 1100 cases.

[Pedda]

The 1150 transmission shaft is bored and shut with an alu plug. You mean that plug?

 

If so, it does nothing. You can extract the plug and install a hydraulic actuated clutch release assy with a pushrod working from the sprocket cover side right through the transmission shaft, just like some later gsx 750 models have. The shaft is bored just for that purpose.

Quite some years ago I did a thread (or was it just a single post thread) with that modification and what is needed plus part numbers. Could well have been on the old OSS site. Maybe someone saved that post?