3c gear selector problem

R

RUSS

Full member
Hello all.
Recently we replaced rear drive chain and sprockets on the 3C. All went well until we found that 4th gear was now hard to shift down to. Seeing as the problem arose on the first 5 minutes after the above mentioned work, we assumed the problem was caused by not putting things back as they should be. So far we have checked alignment of the inner and outer covers as Cam suggested (tapping they actually did improve things slightly), Checked the clutch action, checked the spindle mark aligns with the inner shaft mark in neutral, checked for binding on the splined input shaft, and checked the cam setting to ensure the throw is even between up and down movements. We spend a lot of time on fine tuning the cam adjustment. The travel of the selector seems to come to a hard stop when trying to select gears without a gear being selected. Changing the cam rotation just shifts the problem to either going up or going down the higher gears. The return spring doesn't feel like it is doing it's job effectively and the gear lever needs to be jiggled up and down to select a new gear.
It just seems we are missing something here and it is frustrating. Can anyone help with this one?
Thanks
Russ
 
How much force did you use to fit the gearbox sprocket?

On my 3C when I fitted a new sprocket I used slightly more force than was prudent and had exactly the same problem as you.

If you whack the sprocket in place you seriously run the risk of buggering up the gear selector fork for 4th/5th change.
 
Hi Russ,
You are saying it is a 3C
Did an engine for Norm a couple of years ago, lined the gearbox selector cog up using the machined mark, when he picked it up he told me later it was missing gears.
The machined mark was in the wrong place.
just check that when you have the mark alligned that you are not one peg too advanced

worth a look
 
Maybe just loosening the screws and slightly moving the cases forward (tapping might be necessary), then tightening the screws again while holding the cases in their position would be enough.
Did you check also that the return spring is in the correct position?
 
I second the advice offered by JLO.  Setting that up is very fiddly.  I've spend days trying to get it right on my Mirage on more that one ocassion.  It requires a defy touch, put the cover on very loose and check the engagement, then go easy with the torque.  In one instance, I found my solution was doubling up the gaskets on the cover.  I still don't understand why that was necessary when one gasket was fine before, but Laverdas are Laverdas....
 
Ok, Thank you all. All very helpful and thankfully behind us as of today. It seems the positioning of the selector spring is critical, as is the cam position which is best adjusted while in 4th gear. The alignment marks seem right and by good design it could all be done without the engine coming out. Happy days again and nice to know we are not alone.
 

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There is a cam on the selector spindle which is easy to mount 180 degrees out of phase.Then you have to toggle the pedal to go down the gears..I bet this is your problem ~

joe
 
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