Swirl Posted July 11, 2015 Share Posted July 11, 2015 Advice wanted, I picked up a 1996 gsx1100f last week, this week it has developed a whine in second gear, I have a slabbie and slingy 750 motor knocking about, I have been reading up on 6 speed box swaps, I have read about the 750 being weaker, i've looked for the frankenstein thread but cant find it, which six speed box can i use and is there a how to guide of how to do it thanks Swirl Quote Link to comment
Gixer1460 Posted July 11, 2015 Share Posted July 11, 2015 Lots been written about this over previous two forums.......personally I wouldn't! 6 gears in the same space as 5 physically means they are thinner and therefore will carry greater load per tooth power being equal between 750 and 1100But the torque of the 1100 means it doesn't NEED 6 gears. So, add greater twisting force / torque on gears that are physically smaller and they are likely to fail. Some say theyare fine but could you trust something that is now getting on for 35+ years old? 2nd gears in Suzi boxes are notorious for wearing the dogs - starts with a whine thenjumps out ...... as its coupled with 5th you might have 4 gears to replace! 1 Quote Link to comment
clivegto Posted July 11, 2015 Share Posted July 11, 2015 Lots been written about this over previous two forums.......personally I wouldn't! 6 gears in the same space as 5 physically means they are thinner and therefore will carry greater load per tooth power being equal between 750 and 1100But the torque of the 1100 means it doesn't NEED 6 gears. So, add greater twisting force / torque on gears that are physically smaller and they are likely to fail. Some say theyare fine but could you trust something that is now getting on for 35+ years old? 2nd gears in Suzi boxes are notorious for wearing the dogs - starts with a whine thenjumps out ...... as its coupled with 5th you might have 4 gears to replace!I agree, had to replace 2nd and 5th gears on me b12 too many wheelies n stuff when younger it rounded the dogs off both gears.But if it is whing probably the output shaft bearing cause been to tight chain, easy to replace but you have to split the crankcases M8. Quote Link to comment
kokolis Posted July 11, 2015 Share Posted July 11, 2015 Whining on a particular gear means that the problem is on that gear or the pair of it Quote Link to comment
Swirl Posted July 12, 2015 Author Share Posted July 12, 2015 Will wizz it out this week and assess,I know its not recommended but which 6 speed box goes straight in, if ive got one it can go backmon the road, engines gotta come out again to get put in the fighter sooner rather than later Quote Link to comment
Swirl Posted July 12, 2015 Author Share Posted July 12, 2015 Or where can i source the pair of gears used/new Quote Link to comment
kokolis Posted July 12, 2015 Share Posted July 12, 2015 New them are still for sale, a parts list makes thing easier.Used on that site, hole box for +_ 150 Quote Link to comment
jonny1bump Posted July 12, 2015 Share Posted July 12, 2015 If you see some gearboxes I have replaced I would certainly stick with 5 speed. I have personally had the dogs shear off side of second gear with a scary lock up coming into a corner.The 6 speeds just not got the same strength especially when you have an engine making good power. Quote Link to comment
clivegto Posted July 12, 2015 Share Posted July 12, 2015 You can get new gears from Robinsons foundry not that cheep but tell them you are OSS member and you get 10 % discount. Quote Link to comment
Davy1100 Posted July 13, 2015 Share Posted July 13, 2015 get the gears undercut makes them a lot tougher Quote Link to comment
Oliekoel Posted July 13, 2015 Share Posted July 13, 2015 i thought i could find the pricing for the gears ... but....it's a shame they dont have anything for gsxf1100(cmsnl.com) Quote Link to comment
Captain Chaos Posted July 13, 2015 Share Posted July 13, 2015 try www.motorcyclespareparts.eu Quote Link to comment
Gixer1460 Posted July 13, 2015 Share Posted July 13, 2015 As said above - Robinsons Foundary - most of the stuff is here?..... http://www.robinsonsfoundry.co.uk/content/pages/shop/parts/Suzuki/GSX/GSX1100F/FJ-FR 1988-1994/gsx1100ftrans.htm Quote Link to comment
canamant Posted July 13, 2015 Share Posted July 13, 2015 Slabby 750 gearbox won't go unless you want to use the slabby clutch because the primary gear shaft and clutch splines are different to all the other oil boilers. I'd go for a J/K box because the bottom ends are the same. Also check the primary shaft. If it's solid and you need it hollow you'll have to get it machined out and you might also need to make a new push rod or push mushroom. Quote Link to comment
Captain Chaos Posted July 14, 2015 Share Posted July 14, 2015 or use the 750 cable clutch actuation, on the clutch cover (right side) Quote Link to comment
Mc Nasty Posted July 14, 2015 Share Posted July 14, 2015 Slabby 750 gearbox won't go unless you want to use the slabby clutch because the primary gear shaft and clutch splines are different to all the other oil boilers. I'd go for a J/K box because the bottom ends are the same. Also check the primary shaft. If it's solid and you need it hollow you'll have to get it machined out and you might also need to make a new push rod or push mushroom. Is slabby 750 helical clutch gear, 1100f crank is helical drive gear Quote Link to comment
Gixer1460 Posted July 14, 2015 Share Posted July 14, 2015 Is slabby 750 helical clutch gear, 1100f crank is helical drive gearSods law being what it is and if the oilers are anything like the aircooled motors, the primary gear ratios are different between 750 and 1100. So whatever you choose you'd need the matching basket! Quote Link to comment
jonny1bump Posted July 14, 2015 Share Posted July 14, 2015 get the gears undercut makes them a lot tougher I'm afraid it does not make them ttougher but what it actually does is make the gears engage and stay locked and not bounce back apart or jump out of gear however you wish to call it. Quote Link to comment
canamant Posted July 14, 2015 Share Posted July 14, 2015 Slabby Primary gears are straight cut. Only helical is 1127F Powerscreen. Keep on forgewtting that some people use 1127Fs. You are stuck using a 750J/K or a a 750F or a 750L/M box. One of the engines (might even be a 600 bandit >) has a shorter primary shaft. If I was putting a 6 speed box in an 1127 I'd just buy a scrapper 750 and see what fitted. Slabby Race r 1 (750) has a 750M bos and clutch and I had to make clutch release parts myself to make it all work but it was a simple job. Quote Link to comment
Swirl Posted July 16, 2015 Author Share Posted July 16, 2015 There's the thing I have a slabby engine sat there, would rather keep it 5 speed but if it turns out to be a 2nd gear the price between a j-p model and a r model is ridiculous, is that the year, its on a 96 P reg only way to find the damage is to rip it apart I suppose, cheers for the Info so far Quote Link to comment
Davy1100 Posted July 19, 2015 Share Posted July 19, 2015 I'm afraid it does not make them ttougher but what it actually does is make the gears engage and stay locked and not bounce back apart or jump out of gear however you wish to call it.cheers jonny i always thought it made the gears tougher wearing Quote Link to comment
Duckndive Posted July 19, 2015 Share Posted July 19, 2015 I seam to recall Rupperton saying the later models "M onwards" had undercut box from factory and if you buy new OEM gear's they are undercut anyways 1 Quote Link to comment
McLean Racing Posted July 20, 2015 Share Posted July 20, 2015 Correct Clive. New gears from Suzuki are undercut from the factory Quote Link to comment
Swirl Posted July 21, 2015 Author Share Posted July 21, 2015 Haven't took the engine out yet so, assessment when stripped is away a way as i'm on holiday thursday for 3 weeks Quote Link to comment
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