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Gearboxes
#11
Currently got my 3 synchro box in bits because it jammed having thrown the balls and springs out and the only excessive wear I have identified so far is in the layshaft. Something approaching 30thou as opposed to the 4 - 5 recommended, maybe a wonder it was working at all.
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#12
Interesting Simon. Assuming it's the 1/2 hub on the upper shaft you are talking about the layshaft shouldn't influence it (though plainly does need its bush fixing).

Which implies - if your main shaft play is really within limits - that the detent balls can be exposed merely by a vigorous gearchange... New detent springs and balls will help but not guarantee. The relationship between selector bar and gate may be worth looking at.
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#13
Yes it’s the 1/2 hub, I wasn’t sure how the layshaft would be the culprit but the selector balls were also out so maybe involved. Casing and layshaft are currently at a local engineering firm for sorting. I’m new to all this so learning on the job, will recheck all tolerances.
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#14
(13-01-2019, 12:25 PM)Simon Scott Wrote: Yes it’s the 1/2 hub, I wasn’t sure how the layshaft would be the culprit but the selector balls were also out so maybe involved. Casing and layshaft are currently at a local engineering firm for sorting. I’m new to all this so learning on the job, will recheck all tolerances.

I don't know if you caught it but there was quite a useful thread on here recently Simon about addressing layshaft bush wear.

I think to resolve the question about play you'll need the box back together but frankly having got this far won't you consider fitting new bearings? They aren't crazy expensive. You may find you have to transfer the snap ring from old bearing to new and perhaps shim to get a suitable amount of end float.
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#15
Yes makes sense to renew the bearings while it’s apart. As I said learning on the job and trying to build my confidence/courage to get stuck in.
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#16
The layshaft bush can be removed  refaced and shimmed using this simple tool, I allow 2thou end float.

Terry.

Assemble laygear and shaft back into box and check clearance at the rear with feeler gauge.      Terry


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