5 speed GearBox Mainshaft

[whacker]

Good Day 1st Post, and a Question
Thanks

I have a 5 speed box from a cali II 80's that has the #5 gear moving so far back on the main shaft that it has worn an arc into the boss (aluminum), as well as the outer bearing race on the output shaft perhaps 1 MM deep.

The shaft has the standard 2 mm shim and thrust bearing with washers on the forward end.

Find this really unusual, it appears there should be a shim at the rear and less of a shim at the forward end.

Perhaps the gear cluster 1 and 2 (I believe) has moved rearward on the main shaft.

Sorry no picture of the mess , but did attach some artwork showing where the wear is

Looking for other ideas, anyone else found this problem?

Thanks in Advance

whacker

 

[john zibell]

Curious situation. I'd check for a bent shift fork. Perhaps the shift drum needs to be shimmed forward? Hard to say without seeing the position of the shift collar in neutral through the oil fill hole.

 

[whacker]

Hi Tk You
That's perhaps an idea ,

The 5th gear on the main shaft is not intended to move axially on the shaft, so I don't understand how the shift fork will affect it's location.

The transmission is apart, so every thing can be seen

Thanks whacker

 

[john zibell]

You are correct on that. I made an incorrect assumption. Didn't have enough coffee yet. The service manual should give a specification for the length of the shaft. That is the one that floats and has a thrust bearing at the front. Someone may have placed an extra washer there in the past. Check a parts manual for what should be there.

 

[whacker]

Hi Thanks John

Yes there's a 2 mm shim at the front then a thrust washer, the bearing and another thrust washer, and then the hub of the Gear there.

I did see the Number in the book for the length of the shaft, but haven't measured yet.

I could perhaps use a thinner shim 1 mm and then I guess add a shim at the rear, to keep the shaft forward and give that rear 5 gear more clearance.
I do need some shim at the front as just the thrust washer causes interference with the case there

As near as I can tell there is no shim called out in Parts for the rear, though getting one perhaps 17 ID x 1.5 mm should not be that difficult.

I find this really strange,

Is this a special gearbox made shortly after a trip to the Wine Burg .. Huum

whacker

 

[john zibell]

I don't recall there being a shim before the washer for the thrust bearing. Can you check the parts manual? My desktop PC is down for repair and I'm working from my laptop so I don't have quick access to parts information. If shim is required, was the gasket missing for the rear cover?

 

[whacker]

Parts shown in Picture attached

Movement of gear enough that 1 mm or so of metal removed inside rear cover.
Yes, there was a rear cover gasket.


whacker

 

[whacker]

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