Pinion Gear Damage

[kzmako1996]

Found pinion gear damage on lower unit inspection. A little chip. Doesn’t look like it’s Any thoughts or recommendations on of gear needs to be replaced?

All the other teeth on the gear look fine, all the other gears in the lower unit do not have any damage.

Lower unit from 1993 200TXRR.

[robert graham]

If new gear can be found then probably best to replace it....otherwise use it as it is....

[99yam40]

did you find metal in the lube when you drained it?
or on the magnet on drain screw?

I would think any damage where the gears mesh would throw some metal which would get into the bearings

[kzmako1996]

Water in the oil(emulsified) and drain plug was “fuzzy”. In all honesty I was thinking that I would see more damage to the gears and bearings that I did.

This is my first time into this gearbox since owning it. Just looking for a cost effective way of getting this back together and understand the cost/benefit for 25 year old motor.

If I change the pinion gear, I’m looking a shimming evolution. Correct?

[panasonic]

Kzmako, if you plan on using the old gear I would at least take a Dremel with a small grinding stone in it and smooth out the damaged area on the gear. Just take the the sharp edges off and smooth out the rough surfaces. This will help get rid of any small microcracks they may be there around the damage. A good inspection with 10X magnifier would hurt as well.

If going with a new gear, I would measure the thickness of the old one and compare it to the new....my bet would be they will be the same...so the old shims would probably work out for you.
It would be a good idea to check the backlash of the gear set as per the service manual so you know that it is in fact correct vs throwing it together and hoping it is.
Best of luck

[99yam40]

Kzmako, if you plan on using the old gear I would at least take a Dremel with a small grinding stone in it and smooth out the damaged area on the gear. Just take the the sharp edges off and smooth out the rough surfaces. This will help get rid of any small microcracks they may be there around the damage. A good inspection with 10X magnifier would not hurt as well.

If going with a new gear, I would measure the thickness of the old one and compare it to the new....my bet would be they will be the same...so the old shims would probably work out for you.
It would be a good idea to check the backlash of the gear set as per the service manual so you know that it is in fact correct vs throwing it together and hoping it is.
Best of luck

fixed that for you

I agree the gears should be machined to great tolerances,
but the cases are what end out not quite as good,
so they need to be shimmed to make up the difference

[panasonic]

Thanks..I am sure I read that post twice before I hit the post button!!!

And yes gears,bearings and shafts are very precise. It is the cast cases that have the variants in them when machined so that shims are necessary.

[99yam40]

fixed that for you

I agree the gears should be machined to great tolerances,
but the cases are what end (out) up not quite as good,
so they need to be shimmed to make up the difference

heck I did not do much better on proof reading my post

[kzmako1996]

Thanks guys. I’m going down the path of replacement as my son will be on this probably more than me this season. A question about the shimming process.
1). (Assuming I wanted to start from scratch on the shimming process and have access to the shimming gauges) I can’t read the casing variation numbers, the manual states to assume a value of 0...In the end will I just be guessing reshimming and adjusting based on the backlash measurements anyway for adjustments or is there another way.
In other words how can I use the gauges to work for me rather than the method above?

[99yam40]

I am not sure why you are needing to reshim if you are using the same case.
just use the shims that were in there and check backlash

I am of no help on the shimming process since I have not done it myself