Author Topic: Adjusting 5 Speed Box  (Read 381 times)

Online Kiwi_Roy

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Adjusting 5 Speed Box
« on: April 17, 2021, 06:51:10 PM »
Several years ago I shimmed the gearbox in accordance with Pete Roper and Old Jock aka John Noble's "Inside the Lemon Box", excellent  tutorial but it's a little out of adjustment, I have to throw it into 3rd and 4th.
I think it just needs a slight tweak of the bolt and locknut sticking out the back, it's such a sod of a thing to get at I just lived with it.
Which way do you turn the bolt, in or out to make gear selection more positive going UP, changing down has never been a problem.

Do you have a special tool to reach the nuts while the box is still in the bike?
A link to John's tutorial.
https://www.thisoldtractor.com/guzzitech.dk/pdf/gearbox-rebuilding-john-noble_print.pdf

Thanks in advance.
Roy
« Last Edit: April 17, 2021, 07:01:04 PM by Kiwi_Roy »
72 Eldorado
07 Griso 1100
17 V7iii Special

Moto Guzzi - making electricians out of riders since March 15 1921

Offline 1down5up

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Re: Adjusting 5 Speed Box
« Reply #1 on: April 17, 2021, 07:08:23 PM »
The pawl adjustment bolt is just an eccentric bolt with a lock nut. If you turn it 360deg you end up in the same spot.

You need to know where it is set to start with, hopefully you set it to square/90deg when you installed it so you have adjustment both ways, but as to which way to turn and which way that will then move the shift pawl is anyone's guess..... Unless you know where it was set to start with

Offline Wayne Orwig

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Re: Adjusting 5 Speed Box
« Reply #2 on: April 17, 2021, 09:44:42 PM »
What 1down5up said. Since it is an eccentric, you can't really tell if it need to got CW or CCW. Just turn it a bit and see if it is better or worse. Never turn too much or you will pop the spring off.
And obviously double check the the linkage and such is all free.
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Online Kiwi_Roy

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Re: Adjusting 5 Speed Box
« Reply #3 on: April 17, 2021, 11:45:13 PM »
Thanks Gents, yes I remember now you reminded me, I will figure out how to loosen it and give it a try.
72 Eldorado
07 Griso 1100
17 V7iii Special

Moto Guzzi - making electricians out of riders since March 15 1921

Wildgoose Chase Moto Guzzi

Re: Adjusting 5 Speed Box
« Reply #3 on: April 17, 2021, 11:45:13 PM »

Offline 1down5up

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Re: Adjusting 5 Speed Box
« Reply #4 on: April 18, 2021, 06:44:45 AM »
To losen it just back off the jam nut.

I would only be turning it clockwise (into the case), if you can get 1 full turn that will give you the full range.

If you go counter clockwise and it unscrews past the spring  it's a crab frame, transmission out, transmission cover off job from memory

Offline guzzista

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Re: Adjusting 5 Speed Box
« Reply #5 on: April 18, 2021, 04:58:29 PM »
From looking on the cam like part of the bolt  with the cover removed , it only has 180 degrees of total  adjusnent , 90 degrees  ether  way.
To me it would make sense to set the bolt with the cam area in the middle ( machined area either looking toward the spring or away from it) , then marking the bolt at 12 o'clock. If the  flat part on the cam is towards the spring or away from the spring center then 90 degrees in either direction is the entire adjustment available. . Either way less risk of  the spring " jumping " off
« Last Edit: April 18, 2021, 05:22:23 PM by guzzista »
1975 750S Tribute bike, 1994 Cali 1100, 2007 Ducati GT1000, 1983 SP1000 1967 Vespa SS180

Online Kiwi_Roy

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Re: Adjusting 5 Speed Box
« Reply #6 on: April 19, 2021, 11:55:32 PM »
I tried turning the screw CW today by approximately 1 flat, it seemed to improve shifting up.
I'll leave it there for a couple of days then try it back the other way.
72 Eldorado
07 Griso 1100
17 V7iii Special

Moto Guzzi - making electricians out of riders since March 15 1921

Offline dxhall

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Re: Adjusting 5 Speed Box
« Reply #7 on: April 20, 2021, 10:47:43 AM »
Iím following this thread with interest because my CalVin continues to have gear change trouble.  When I bought it, it would get stuck in 3rd when it was hot.  I took the box apart and reshimmed the shift drum.  Now, it gets stuck in 2d when itís hot. 

Iíve found no reference in any manual to this adjuster, or any explanation of how to set it.

I didnít note where the eccentric adjuster was when I took it apart.  When I reassembled it, I put the adjuster at its midpoint and marked that point on the bolt and case. 

If one flat CW improved shifting up, I may try one flat CCW and see if that helps shifting down.  Did I mention what a PIA this bike has been?

Offline moto-uno

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Re: Adjusting 5 Speed Box
« Reply #8 on: April 20, 2021, 11:14:37 AM »
   ^ We call that a test of our patience  :thumb: . Peter

Offline guzzista

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Re: Adjusting 5 Speed Box
« Reply #9 on: April 20, 2021, 05:07:21 PM »
Quote:If you go counter clockwise and it unscrews past the spring  it's a crab frame, transmission out, transmission cover off job from memory
 Quote:The pawl adjustment bolt is just an eccentric bolt with a lock nut. If you turn it 360deg you end up in the same spot.

The Eccentric only has 180 degrees of total  adjustment , 90 degrees  ether direction.
One flat is 1mm .( Thickness of the step at tip of eccentric to keep spring down) To Keep going CCW can and will jump the spring. Proceed with caution.
« Last Edit: April 20, 2021, 05:28:03 PM by guzzista »
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