Shimming the kicker shaft
- Thread starter comnoz
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Nice video but why do you have a sectioned gearbox case?
I didn't shim my layshaft instead to reduce the end float I did not fit the inner cover to casing gasket. This gave me 8 thou of end float and no leaks with good joint faces plus Wellseal (dangers to say it doesn't leak but it's in the garage so hopefully it won't know I said it an mess the floor up out of spite
). Can you see any issues with this method of clearance reduction ??
I didn't shim my layshaft instead to reduce the end float I did not fit the inner cover to casing gasket. This gave me 8 thou of end float and no leaks with good joint faces plus Wellseal (dangers to say it doesn't leak but it's in the garage so hopefully it won't know I said it an mess the floor up out of spite
). Can you see any issues with this method of clearance reduction ??- Joined
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The layshaft is not stopped from floating sideways by the kickershaft - the 1st gear pinion is trapped between the shoulder on the shaft behind it and the face of the bronce bush inside the kicker shaft. So if you shim the kickershaft (as suggested in the video) you effectively hinder the shaft to float by trapping 1st gear. I agree that the gears need to be shimmed for perfect gearbox funktion. You can shim with an isolastic shim at the kickershaft or as I do with a new bronce bush (made to the correct length) inside the kicker shaft. First gear is the only gear inside the Norton box without a negative cut on the engagement dogs - that is the main reason for jumping out of gear. With a negative cut the gear will not jump out under load, in fact the load holds it in - i.e. you cannot change gear under full load. In the video you see the other gears engagement dogs have a negative cut of around 5 degr - on my race gearboxes I use 10 degr. Nice video
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Thanks for another great video!
On this transmission, sounds like it needs a .045 shim stack. Would you feel comfortable using 3 isolastic shims for this?
On this transmission, sounds like it needs a .045 shim stack. Would you feel comfortable using 3 isolastic shims for this?
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toppy said:Nice video but why do you have a sectioned gearbox case?
I didn't shim my layshaft instead to reduce the end float I did not fit the inner cover to casing gasket. This gave me 8 thou of end float and no leaks with good joint faces plus Wellseal (dangers to say it doesn't leak but it's in the garage so hopefully it won't know I said it an mess the floor up out of spite
I sectioned the case 20 years ago when trying to make a stock box hold up to racing.
Doing away with the gasket will do the same thing as adding shims. It's often not enough. Jim
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WEAL Norton said:
Yes it is first gear that contacts the bushing. A longer bushing will cure the problem. Since the boxes seem to vary anywhere from .020 to .065 end play I wonder how you know how long to make the bushing unless you custom fit each one.
I have undercut 1st gear at 3 degrees. It definitely kept it in gear but it also made shifting out of first a bit rough. Finding neutral was nearly impossible unless you were rolling. Jim
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elefantrider said:
Sure, just open up the ID a bit so it doesn't hang on the shaft radius.
The material of the shim is not real important. The only movement the shim sees is when you are kicking the bike.
I keep brass shim stock and have a punch for the ID and use scissors for the OD. Jim
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I assemble the box on the bench with the layshaft and kickershaft, measure endplay of kickershaft, remove the bush and replace it with one cut to the correct length - giving around 0,3mm endplay.comnoz said:
Comnoz,
I realize your logic but my concern is that your demo show a very sloppy outer race of the ball bearing. To me this is not realistic. The outer race should fit tightly, as would the inner race to the layshaft, and not allow for the movement you suggest. If either is loose or as free as you show, shimming will not prevent future failure as it may be subject to spinning in or on either race. It has been discussed many time the need to adhere a poor fitting layshaft bearing into the case.
As with the "superblend", I believe the shimming is more needed to maintain full roller to race contact, in conjuction with some of the advantages you suggest. Having it ride .050" to even a 1/16" off seated may suggest that it might nullify any load bearing advantage of the "superblend", unless there are manufacturers spec to show otherwise.
Anyhow, that's how I see it.
Back atcha.
I realize your logic but my concern is that your demo show a very sloppy outer race of the ball bearing. To me this is not realistic. The outer race should fit tightly, as would the inner race to the layshaft, and not allow for the movement you suggest. If either is loose or as free as you show, shimming will not prevent future failure as it may be subject to spinning in or on either race. It has been discussed many time the need to adhere a poor fitting layshaft bearing into the case.
As with the "superblend", I believe the shimming is more needed to maintain full roller to race contact, in conjuction with some of the advantages you suggest. Having it ride .050" to even a 1/16" off seated may suggest that it might nullify any load bearing advantage of the "superblend", unless there are manufacturers spec to show otherwise.
Anyhow, that's how I see it.
Back atcha.
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pete.v said:
Well I do suggest shimming with a roller, the same as I suggest shimming with a ball bearing.
Obviously, using a ball bearing will keep the layshaft from moving but it will not have any effect on the depth of engagement of the first gear set. Jim
comnoz said:
Agreed. Giving the kickstart pawl as much meat as possible to do its thing will save on repair in this area. I have seen many pawls worn out only 1/2 to about 2/3 across.
I am fortune not requiring shims after my last rebuild with 5 to 10 thou max. I shimmed up a roller once and did not like the feel. I guess it's just seemed kinda a funky to me.
I run a "good" ball bearing now and am very comfortable with it.
You know as well as any that these boxes need TLC to keep them alive, particully in how we operate them going on down the road. With the power and torque that these bikes produce, it's easy to forget this achilles running so close to to our own.
Just some thoughts.
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CAN YOU GIVE ME THE DIMENSIONS OF THIS SHIM? My current Norton is jumping out of first when going up hill, maybe this is the cure. You, or someone, should sell a small asst. of shims just for this problem.. Thanks
Peter R said:
You need to open up the ID a little as to not interfere with the radius on the kickstart shaft. Once you slip on one of these iso shims, you will see that it will not sit flush to the face. A couple trips around with a dremal tool will bring it home. It is not possible to adjust the end play without doing this to the iso shim.
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Thanks...I see what I need and buy some
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