Hard downshifting

I hope to pull the primary off this weekend to change out the gearbox sprocket and add the dual gearbox adjuster. I have been thinking about what else I should do while I'm in there.
I have noticed that shifting down from 4th can require a lot of pressure on the lever. If I recall correctly, its worse if I've been cruising in 4th for an extended period of time. Seems that going down from second can be a problem sometimes too. I always free the clutch plates before starting up and I'll clean the plates when I have the primary off.
I understand that the drive chain can pull on the gearbox and that can cause the primary chain to tighten up a bit (dual adjuster should take care of that), but it doesn't make sense to me how that would affect shifting down. Since I'm decelerating when shifting down, the tension on the drive chain will be less than when accelerating, so the primary chain tension should be fine. I spent quite a bit of time getting the primary chain adjusted as loose as I dared, but I don't remember checking it when it was hot. I'll definitely do that.
Any ideas on what could be causing a hard downshift? Don't seem to have any problems shifting up.

Thanks,
Ben

In any case, I'd try loosening the chain a bit and see if it helps. It's easy enough to do. Just make sure you do it in the right order, tighten first then loosen.

Dave
69S

Essentially no one ever fails to nip up the gear box bolts enough to cause drive chain to pull extra tension in the primary chain and certainly even less with powerful enough engine to over come the gear box bolts. There is some slight slop in the bearings that drive chain and primary fight over but its not enough to detect in shift behavior. It is heat expansion of everything, cradle to sprockets that tighten up primary. Cold tension always feels too loose to me too. Too tight a chain is classic for hard shifts and N finding, but a number of other things can too, pawl spring, thin bushes cracking up, dog faces mushrooming over, TS main shaft nut backing off, etc. I'd suggest loosing chain first to test, as too tight really strains the shafts and bushes to point of distortion that remains chewing up even after tension corrected.

Maybe gearbox top bolt loose ?

Thanks for the input. I'll check the primary chain tension. I'll have to reset it anyway when I put the primary back together. If it's a case of the top gearbox bolt being loose, that will be taken care of as well. I'm hoping the dual adjuster and a proper chain tension will clear all of my issues up at the same time. It's running the best it ever has, if I could just get these couple issues sorted, I think it will be dialed in.

Ben

I hope your hopes are correct but dual adjuster benefits are only noticed to get tedious belt drives aligned and not at all needed for triplex chain running or any affect on sweet shifting, so let your imagination fly on the listed possibilities you've yet to learn to consider. The possible bad news is it only takes one over tight event to bend shafts to a slight candy cane cork screw so even after primary adjusted - tranny troubles remain and wearing out is vastly accelerated till attended to the routine expensive more time/money way. You will definitely enjoy a taller over all ratio.