Gearbox problem?

[David Thompson]

Bought my s/h Clubsport K1100 in late September them went on holiday, then got tangled up in work and so only now am I paying some attention to the more serious matter of enjoying myself with the car. I went to Goodwood a week ago to get it noise tested (104db at 8krpm static) and discovered I could only select first gear. I tried rocking it in 1st but couldn't get it to select any other gears. The car is fitted with a Flatshifter, but I can't think this would inhibit gear selection - and they have confirmed it wouldn't - anyone any ideas?

Thanks in anticipation

Edited by David Thompson on Friday 13th November 14:40

Edited by David Thompson on Friday 13th November 14:53

[splitpin]

As I understand it, the 'Flatshifter' can be fairly easily disconnected (at the gearshift lever end?), so that's the first thing I'd do i.e. to confirm whether or not the problem is with the Flatshifter. First step in the process of elimination.

Thinking about it, given the straight cuts/small syncro on motorcycle gearboxes, I'd also get the rear up on axle stands and try gently engaging the gears under load i.e. with the engine running and the gearbox driving.

Edited by splitpin on Friday 13th November 15:21

[fergus]

This problem can sometimes occur on bike based gearboxes, as the selector is connected to the splined gear selector shaft via an elbow which slides over the splines. It is possible to slide the elbow on to the shaft in such a manner that only 1st is avialable to you. Have you looked at the route the gear selector shaft is taking from the lever all the way back to the splined input shaft. The way round this on bikes is to slide the elbow off the input shaft and move it around a few splines prior to sliding it back on.

As the split-master says, disconnecting your flat shifter may reveal the problem (assuming it's a mechanically actuated shift mechanism)?

[splitpin]

Good thinking Fergus; 'integral' neutral twixt 1st & 2nd, so entirely feasible. Reminds me of a useful tip; when you've got the male gearshaft splines and the female lever splines in the correct relationship, use a permanent marker to put a centreline axis on the end of the shaft to line up with the pinch gap of the lever.

[David Thompson]

Fergus, a shift rod has been connected to a shortened selector shaft. The shift rod contains an actuator which senses the pressure applied along the shaft when changing gear, and the engine revs either blip or drop depending on going up or down the box. I can't see how this would effect the ability to change gear except - as you point out - the post Flatshifter fitting length of the selector shaft has changed sufficiently to allow only 1st to be engaged.
I guess I should remove the selector shaft at the gearbox end and see if I can get all the gears by moving just the arm from the splines - is this what you are suggesting?

[splitpin]

What Fergus is saying is that it's possible to get the lever and shaft spline relationship so out of kilter that you'll only be able to get first - or indeed every gear except first if you get my drift.

It's entirely possible that the flatshifter shaft is restricting the necessary gearshift lever movement. Might be useful for you to have a look at Marshy's very professional installation >

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

It well evidences that a flatshifter should do the listening not the talking.

Like I said, first step should be to detach the flatshift and see what happens - if it still won't go into 2nd etc, try adjusting the relationship of the shaft and lever splines: Can't say whether clockwise or anti-clockwise as that depends whether you pull or push to go up and how you've got your entire stick to lever mechanism set up.

[fergus]

...Or that the strain gauge is effectively not allowing the requisite travel in both directions?

A solid shift rod, which tend to have LH and RH threads at each end (to allow for slack to be tuned out) will let you see if the configuration of the strain gauge in the shift rod is your cause.

good luck!

[David Thompson]

Fergus,

The Flatshifter is not inhibiting the horizontal shaft movment, and I've altered the elbow / spline angle by about 25/30 degrees in both directions but no joy. I'm assuming that anything inbetween would be the same, or are you saying I should try it a few splines at a time?

Thanks in advance.

[fergus]

David Thompson said:

Fergus,

The Flatshifter is not inhibiting the horizontal shaft movment, and I've altered the elbow / spline angle by about 25/30 degrees in both directions but no joy. I'm assuming that anything inbetween would be the same, or are you saying I should try it a few splines at a time?

Thanks in advance.

OK. If you disconnect the flatshifter, and just leave the elbow, are you able to use the elbow to move up and down the box? If yes, then there's something closer to the gearshift linkage which may be the cause? If not, I'd suggest moving only a few splines at a time, perhaps 2 or 3 in either direction.

If that still doesn't work with nothing connected other than the elbow, try mounting it so that the elbow sticks out in the same plane as the shift linkage rod (will ensure it isn't fouling on anything). If it still doesn't allow you to change gear, I think you'll need to open the gearbox cassette and take a look, you may have a bent selector or worse?

softly softly, catchee monkey!

[splitpin]

Having ruled out the flatshifter, you should now aim to rule out the gear linkage itself.

Disconnect it completely, leaving only the gearshift lever on the gearbox spline; with it's ass up in the air on secure stands and a mate dipping the clutch and operating the throttle, it should be entirely possible to get round the back (and barking instructions to your soon to be ex-mate),use the lever itself to see whether it will go up and down the box using just a firm nudge; you may need to use a shortish length of flattened tube to go over the free end of the gear lever to get a bit more leverage on the nudging.

If it goes up and down the box, the problem is with the gear linkage itself, most likely too much play or it's relationship with itself enroute to the lever. It's dead easy to put the linkage ass about face so it defeats itself. I've seen a lever put the wrong way up so it's prevented from making the necessary movement because it's hitting the firewall chassis. If it won't go up and down the box with the complete linkage removed, it's a gearbox problem.

Edited by splitpin on Wednesday 18th November 00:05

[fergus]

I think we've said exactly the same thing, using different words!

[splitpin]

fergus said:

I think we've said exactly the same thing, using different words!

I thought so too, but was not 100% sure enough to make the claim

[BertBert]

I've just had this most cunning of ideas...

[David Thompson]

I've come to the conclusion that it is a gearbox problem. I take it I need to remove the engine / gearbox from the chassis to access the box?

[splitpin]

David Thompson said:

I've come to the conclusion that it is a gearbox problem. I take it I need to remove the engine / gearbox from the chassis to access the box?

Sorry to hear.

Ping me an email through PH so I've got your personal one and I'll email you something very useful.

Is the lever stiff? I've heard that the Kwacker gearbox can get reluctant enough to not change up simply because of a build up of crud inside the case around the shaft / selector drum.