The "Book" says that driven gear should be press on shaft until outer face of the gear is flush with end of brake drum shaft.
Having done that the clearance between driven gear and slow speed gear is 0.02" but book says it should be "approximately" 0.006".
Is it important, what would be the consequence of leaving a higher clearance? Where should I put shims to reduce it ?
2 thou is too close. In operation, the rear side of the driven gear will contact the end of the low speed shaft and make a grinding noise. Had that happen to me requiring a full tear down to correct. You noticed it right away. All you need to do is use the puller and distance the driven gear AT LEAST 6 thou away from the slow speed shaft. After my experience, I set the clearance at 10 thou.
BTW, run the feeler gage all around the driven gear since the clearance varies a bit. Make sure you have at least 6 thou clearance at all points.
That's good to know about the clearance Richard.
I hope that's not what my slight grinding noise is but it could be.(DANG IT)!!
My 21 Touring rebuild does have a slight grinding noise very similar to what is being described in your post.
All is fine until the low speed is engaged.
IF that is what is I wonder if this has happened before and just left alone. I have noticed some wear marks on old drums before.
Maybe it will just wear away and not blow the drum??? I wonder.
Didn't Philippe say in his post that his clearance is 20 thousandths? He is looking for suggestions on where to shim to bring the clearance down to 6 thousandths like the book says.
I don't think you can set the clearance. Everything just goes together. I suppose it is possible that some defective driven gears could be out there. Your best bet is to try another.
Yes Mark, I have 0,02" instead of 0,006".
I am not using the shaft that came with the driven gear because the brake drum was broken and I found another good used one. I am reluctant to change the gear because it matches with the other gears
As far as a noisy transmission is concerned I always thought there might a little noise because of using replacement parts to make up a good transmission.
When installing the driven gear I have pressed it on till its flush with the drum shaft as I remember.
Did the transmission parts have machining allowances when they were manufactured back in the day?
Maybe that's why some transmissions seem to fit up a little different than others.
This happens when installing axle gears on good used or new axles. Some are harder than others and some are not.
This may be what Phillipe is experiencing using different parts.