layshaft woes, 5-spd

[RoMoMoTo]

I have my 5-spd. Quota transmission apart to investigate a clicking/ratcheting noise that's always been there. What I found is that the engagement dogs for fifth gear don't move far enough apart to prevent them from contacting each other under when in another gear (or neutral). The reason seems to be: the two-piece layshaft has a considerably larger gap than I've seen on other 5-speeds between 2nd and 3rd gears, which means 3, 4 and 5 sit higher (closer to the rear) than they should. Hence the 5th gear dogs sit closer - too close - to the engaging ring.

I took the layshaft to a shop with a hydraulic press, hoping they could press it together and close that gap. But after applying some serious mojo, there wasn't any movement between the two halves.

So I'm looking at changing the shimming of the shift drum to bring the 5th gear fork up a bit further away from the gear dogs, and hopefully that won't screw up alignment of the other forks. (I'd already shimmed out the slop using Mr. Roper's excellent instructions)
But before I do that, does anyone know if I can actually get the layshaft pressed tighter together, or will application of more pressure likely result in a loud bang and a broken part?

[Dick]

Are you sure your not referring to the mainshaft. The layshaft is a one piece solid shaft with all the gears and sliding engagement rings, except for fifth gear and ring which resides on the mainshaft. . You may not have been pressing on the shaft properly. You need to press on the dogs of the fifth gear to get shaft to close up. You need to make sure nothing is in the gap impeding it from closing. Good luck.

[Wayne Orwig]

Confusingly, the "layshaft" is the output shaft that drives the u-joint.
The "main shaft" is what you are referring to. I have been successful using heat on the outer barrel and pressing it on. I first soaked it in degreaser. Then cleaned and dried. Add a lot of heat to the outer piece. Add loctite. Press in place with a LOT of force. (for me that is pieces of wood and a LARGE rubber mallet)
But then, it is really held in place by the spring loaded locking pin. Pressing the mainshaft together isn't going to be the 'fix' unless that pin is damaged and letting fifth gear go back too much. It sounds like you may need to shim the shaft forward a touch. (or the drum back)

[RoMoMoTo]

Thanks - mainshaft, I stand corrected. My Haynes manual calls it the layshaft in the exploded diagram. In any case, I'm looking at the 2-piece shaft with the big thrust bearing at the front end.

Dick: I looked at the shaft again and can't figure out why I need to to press on the fifth gear dogs rather than the end of the shaft?

Wayne: Are you talking about propane torch heat or more than that?
Doesn't that spring-loaded pin just lock the fifth gear to the shaft? Is there something in the way this all goes together that I can't see from the outside?
As for shimming the shaft forward, I've already done that, and it's down to minimal clearance at the thrust bearing. I'm able to shim the drum back but figured if I can reduce that gap it would be optimal. (I've read what the manual calls for in total length but lack the tools to accurately measure it)

[Wayne Orwig]

Wayne: Are you talking about propane torch heat or more than that?
Doesn't that spring-loaded pin just lock the fifth gear to the shaft? Is there something in the way this all goes together that I can't see from the outside?
As for shimming the shaft forward, I've already done that, and it's down to minimal clearance at the thrust bearing. I'm able to shim the drum back but figured if I can reduce that gap it would be optimal. (I've read what the manual calls for in total length but lack the tools to accurately measure it)

Yes, just propane torch heat, and lots of it, to swell the outer piece a bit.
Yes the pin just hold fifth gear on. But if something was worn there it may let fifth gear move back.

I know that a couple of them that I worked on I thought had a serious issue with the fifth gear coupler hitting fifth gear. But when fully assembled, it didn't happen. It is hard to get the shafts and drum in full alignment without the cover in place I suppose.

[RoMoMoTo]

Thanks, Wayne. I don't think fifth gear is able to move; my issue is just the length of the shaft with that gap.
I'll try heat (and the other steps you mention) and see if I can't press it together. Barring that solution.I guess I'll go with the drum shimming option.

[Wayne Orwig]

Thanks, Wayne. I don't think fifth gear is able to move; my issue is just the length of the shaft with that gap.
I'll try heat (and the other steps you mention) and see if I can't press it together. Barring that solution.I guess I'll go with the drum shimming option.

The problem is that he moving part is simply first and second gear. I don't believe that sliding them will really change the position of fifth gear relative to the main shaft.

[RoMoMoTo]

Wayne, I'm puzzled. Maybe we're envisioning different things. Here's how I see it:
If I can press the two parts of the shaft together, that will bring fifth gear closer to the front, hence open the clearance between the fifth gear dogs. The first and second gears will not move but will remain placed according to the shim adjacent to the thrust bearing.

If I shim the drum so it moves rearward, that will move the fifth gear fork closer to the back, hence open the clearance between the fifth gear dogs.
Right? Or am I missing something? Thanks for your help with this. Sometimes I miss something that's right in front of me...

[Wayne Orwig]

First gear is the one next to fifth. First and second gear are a single piece pressed onto the main shaft, which has third and fourth on the front. Fifth gear is 'pinned' to that large main shaft. Pressing first and second forward may not move fifth, since fifth is pinned to the main shaft and you did not move the main shaft. (it may 'float' forward and accomplish what is needed though.

[RoMoMoTo]

Thanks, Wayne. I had it in my head when I responded that the gears were laid out 1-5, when of course they are not.
But I did not know that fifth is on the same part of the shaft as 3 & 4. In that case, closing the gap will only move 1 & 2, not 1, 2 & 5. Thanks for clearing that up for me.
Seems, then, that I shouldn't bother trying to close the gap, but rather should move the drum back by moving shims.
Thanks Again.