GS tranny in a GT750 box

[Suzukidave]

Was wondering what affect there will be to the clutch bearing on the primary shaft useing the GS tranny as the GT shaft has a groove and a oil supply hole where the GS shaft does not . I know the GS uses the needle bearing on the shaft there so do you think it didnt require the oil supply that the GT sleeve bearing did ? or did the later model GT shafts also do away with this oil supply when they were switched to the needle bearing clutches ?

[tz375]

Err. I can't remember. I'll go out to the shop later and check it out for you.

What did Allan do about teh groove and feed hole? I don't remember

[Suzukidave]

I spoke to Allan and he hadnt done anything to his gear set either , but he was planning to check it out also .

[Suzukidave]

Well after further checking with the GS / GT primary shafts and related parts i then noticed why Suzuki had done away with the groove and extra oiling hole on the GS parts . This came to me when i looked up the GS needle bearing setup on ebay http://cgi.ebay.com/ebaymotors/SUZUKI-G ... ccessories" onclick="window.open(this.href);return false; and saw that the needle bearing rides between the race in the clutch basket and outside the thick collar that goes on the shaft . Then thus the needle bearing is far away from the shaft so oiling thru the shaft was no longer needed . Assembly can now continue due to false alarm , but it was better to think about it now than when everything is together Still it makes me wonder if the shaft change was also made to the MAB GT primary shafts ?

[Suzsmokeyallan]

After discussing this with you Dave its very clear as to whats going on, I'll have to drag out my gearbox tomorrow and look at it more closely.
I'm still considering the little update I was planning with the inner basket spline and the existing shaft hole.
I've got the bearing and collar awaiting a price, as I don't have any for that particular engine yet so we shall see whats the going rate.

[Suzukidave]

Well ... this dragged out saga continues i found out today after bolting the case halves together the transmission wouldnt turn .. tracked it down to the oil splash plate screwed to the top case .. seems the slightly larger GS gears contact the plate and the mounting point requireing a bit of grinding down . So if also doing this mod test fit the primary gear shaft in the top case to make sure there is no contact

[Suzukidave]

[oldjapanesebikes]

Nice !

[ja-moo]

That's a pretty big bend in the intake tract, I guess you had to go that way?

[tz375]

Dave,

looks good with those R1 flatslide throttle bodies and injectors.

[Suzukidave]

That's a pretty big bend in the intake tract, I guess you had to go that way?

Yeah John , space is a bit tight in the GSXR frame needing the upturned throttle bodies so they can connect up to the airbox

[holysmoke]

It may have come out in a later post, but how were the results?

Thanks,
Ron

[Cyzygy]

I would like to thank every one who had input for this conversion. I've just finished a complete rebuild on my 'B' model and fitted a GS transmission. On the street the transmission shifts very smoothly and quietly and the smaller ratio gap between 1st and 2nd very noticeable. I don't know how to post photos unfortunately. I will post another report on this conversion when I take the bike to the drag strip.
Thanks guys.

[Suzukidave]

Thats great .. a feed back on this swapover and a good one at that , did you run into any problems not covered in the topic ?

[Cyzygy]

Dave,
I was aware 25 years ago that the GT and GS transmissions were close and I've always wanted to close the gap between 1st and 2nd. I recently aquired a GS transmission after reading about the conversion on this site. All went well as suggested in the posts, the shafts machined with tip tools, no need for ceramic tips. The oil hole for the clutch basket bearing drilled with a titanium coated drill after an anular oil relief was machined around the shaft like the GT shaft has. I was especially greatfull for the tip about the screw that holds the lubrication weir to the top case jamming on the gear. It has performed faultlessly riding it around the street and I'll have it at the drag strip in a couple of weeks time to test it more. The bike has been built for Nostalgia drag racing, and is legally street registered. If any members would like more details or pictures feel free to email me.
Thanks again guys.
Bob