10 replies to this topic

[andyt]

I'm currently putting my A+ gearbox back together and have rebuilt the mainshaft and installed it into the casing, it turned really easily and smoothly, next I put the layshaft, laygear, roller bearings and thrust washers in and now there is a lot more friction when I turn the main shaft, it is quite free for about a quarter turn then gets considerably stiffer to turn from the 1st motion output gear end. The layshaft endfloat is 3 thou with the original small thrust washer and turned freely when I checked the endfloat.

 

Is this correct or am I missing something.

 

Andy.

[chris27989]

Guessworks would be the best person to answer this question

[Guess-Works.com]

That'll be the baulkrings binding... Put it into reverse and see if you can turn the first motion then ( anticlockwise )

 

If it is really stiff, or impossible, remove the laygear, 1st motion and mainshaft, and change the baulkring on 3rd for either a different one or a good secondhand one..

Also be aware that the 3rd motion and 1st motion shafts are pushed together at the moment by the nature of their installation, until the two are torqued they will always grip the 3rd baulkring to a certain extent.

[andyt]

Thanks John, it was all turning with one hand on the 1st motion output gear, I had changed all the baulk rings for the ones I received from you last week and the gaps to the gear shoulders were good.

 

I had a mad moment this afternoon and took everything apart again convinced i'd done something wrong and had a catastrophe when both of the syncro hubs flew ball bearings and springs everywhere!!!!

 

I'll be on the phone tomorrow.

 

Andy.  

[Spider]

Thanks John, it was all turning with one hand on the 1st motion output gear, I had changed all the baulk rings for the ones I received from you last week and the gaps to the gear shoulders were good.

 

I had a mad moment this afternoon and took everything apart again convinced i'd done something wrong and had a catastrophe when both of the syncro hubs flew ball bearings and springs everywhere!!!!

 

I'll be on the phone tomorrow.

 

Andy.  

 

Tip: When drifting the Main Shaft about in the box, put a rag over the gearset   That'll catch the balls and springs. Just place it so you can see what you need to see though.

[howardwoods]

That'll be the baulkrings binding... Put it into reverse and see if you can turn the first motion then ( anticlockwise )

 

If it is really stiff, or impossible, remove the laygear, 1st motion and mainshaft, and change the baulkring on 3rd for either a different one or a good secondhand one..

Also be aware that the 3rd motion and 1st motion shafts are pushed together at the moment by the nature of their installation, until the two are torqued they will always grip the 3rd baulkring to a certain extent.

 

Hi, I have the same problem. I just assembled the gearbox and is a little bit stiff to turn. I assumed because the baulk rings are new. Does this actually get better when driven (something like running-in)? or there is a problem that can only be handled by replacing the baulkrings?

Thanks

Howard Woods

[Guess-Works.com]

If you can turn it by hand (in reverse) then it'll be fine... Don't forget that when built and on the engine there'll be lots of nice hot oil lubricating the parts..

 

It's only a problem if the baulkrings are so tight that they wear prematurely or polish the friction surface of either themselves or the gear...

[howardwoods]

If you can turn it by hand (in reverse) then it'll be fine... Don't forget that when built and on the engine there'll be lots of nice hot oil lubricating the parts..

 

It's only a problem if the baulkrings are so tight that they wear prematurely or polish the friction surface of either themselves or the gear...

I can turn it when in reverse gear but it's very stiff. I can hardly turn it. Do I need to take it apart again?

Thanks

Howard Woods

[Guess-Works.com]

 

If you can turn it by hand (in reverse) then it'll be fine... Don't forget that when built and on the engine there'll be lots of nice hot oil lubricating the parts..

 

It's only a problem if the baulkrings are so tight that they wear prematurely or polish the friction surface of either themselves or the gear...

I can turn it when in reverse gear but it's very stiff. I can hardly turn it. Do I need to take it apart again?

Thanks

Howard Woods

 

 

That's fine... I assume you have assembly oil/engine oil already lubricating the moving parts.

[carbon]

This may not be relevant, but I'll mention it anyway.

 

Last gearbox I had rebuilt had similar problem with getting stiff once fully assembled. This was eventually tracked down to the new replacement layshaft not being straight (about 20 to 30 thou out of true). And this is not a one-off problem, had another replacement layshaft supplied before Xmas with exactly same problem.

 

Quickest way to check layshaft straightness is put it in the casing so that the small diameter end is just about to go into the web which also holds double roller bearing, then rotate slowly while wathcing for any up-down-side movement of the small end of layshaft. If it's out of true you can see by eye.

[howardwoods]

 

 

If you can turn it by hand (in reverse) then it'll be fine... Don't forget that when built and on the engine there'll be lots of nice hot oil lubricating the parts..

 

It's only a problem if the baulkrings are so tight that they wear prematurely or polish the friction surface of either themselves or the gear...

I can turn it when in reverse gear but it's very stiff. I can hardly turn it. Do I need to take it apart again?

Thanks

Howard Woods

 

 

That's fine... I assume you have assembly oil/engine oil already lubricating the moving parts.

 

 

 

 

Problem solved!!! I replaced the layshaft rollers and now turns beautifully! Thanks for the advice!!

Items replaced:

Layshaft large roller - CHM141

Layshaft needle roller - 88G396