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I am trying to rebuild an A+ gearbox based on the parts included in this kit: http://www.minispares.com/product/Class ... 0to%20shop

After assembling the box, the gears do not turn very well for some reason. When it is build up completely, with the two main nuts torqued up and the C-locking ring fitted into place, it only turns well when 3rd or 4th is engaged. When 1st, 2nd or reverse is engaged, it turns difficult in reverse direction but in forward direction, it barely wants to turn over at all. In neutral, it also does not turn over that well. I have dismantled and build this gearbox up again three times now but I cannot find any unusual issues with the any of the old or new parts. I did noticed however a difference for the newer 13H9513 (with the 11 rollers instead of 14) as it seems they don't let the input gear turn as well as the old ones do. Has any of you experienced similar issues in the past? Any ideas of what the problem might be? Any help is appreciated!

bart

I would strip it and try this

1) build and nip the main shaft minus the baulk ring in 1st and 4th, if it spins better you know that the problem is at either end (as its rare that the middle two baulks will affect how the kit rotates)

2) if its no better, try spinning it with the lay gear removed (in case the layshaft is bent)

3) remove the bearing of the end of the third motion and try the 1st motion in situ without it - ive seen a box recently where the 1st motion was damaged inside and the bearing didn't go fully home, when nipped up the bearing was deforming and jamming the box up

4) if its no better strip it and remove the forks, then try again (tedious I know)

boxes like this are real temper testers!

I've had the EXACT same thing happen a month ago. I found that the 1st motion shaft interfered with the mainshaft. Does it turn ok in 1st when the 1st motion shaft isn't completely "home"?

Thanks for these hints. You guys made me think a bit more about things. What surprises me is that it basically turns well in 3rd (and 4th) but not in any other situation. This makes me think that there is something wrong around the 3rd/4th hub. If it would only have turned well in 4th, I would have suspected the 1st motion support bearing more strongly.

I will dismantle it again and check for two things:
- 1st motion support bearing position (I visually checked the gear and shaft - they seemed both perfectly ok)
- gear selector shaft. Perhaps it is bent somehow such that the 3th/4th fork is tilted and causing the hub to be tilted, thereby constantly pushing the 3rd baulk ring in a tilted way to the gear unless 3rd or 4th is engaged. Does this make any sense?

Wish me luck...

Bart, when I rebuilt my box I had a similar issue. It was the second baulk ring grabbing the gear. In reverse direction it would rotate with some effort but in normal operating direction the gears would always lock. I had to swap the baulk rings around and after oiling them they were fine. Did you oil the baulk rings? I'd try to do it first and then follow rich's suggestions. A bent rod/fork seems plausible too.