Evinrude 40 HP (1973) Pinion Gear Problem

[aquaman8]

Hi All,

Just took a gear case apart on an old 1973 40 HP Noresman (Model 40355)and found that one of the teeth on the pinion gear (driven by the drive shaft) is missing about half the material along its length. There were metal filings and some chunks in the gearcase. Some bearing surfaces are a little scourded, especially the clutch dog.

I know that this can't be good, but I had a couple of questions:

1) Can I run it like this or will it rapidly self-destruct?
2) If it does self-destruct will it cause significant collateral damage inside the gearcase?
3) Can I find a just a used pinion gear and replace the broken one, or do I need to replace the pinion gear and the forward and reverse gears as well?
4) How big a job is replaceing what needs to be replaced?

Thanks for taking the time to help an outboard newbie through the teething process (pardon the bad pun!)

Mitch

 

[darrklim2]

Re: Evinrude 40 HP (1973) Pinion Gear Problem

Hi All,

Just took a gear case apart on an old 1973 40 HP Noresman (Model 40355)and found that one of the teeth on the pinion gear (driven by the drive shaft) is missing about half the material along its length. There were metal filings and some chunks in the gearcase. Some bearing surfaces are a little scourded, especially the clutch dog.

I know that this can't be good, but I had a couple of questions:

1) Can I run it like this or will it rapidly self-destruct?
2) If it does self-destruct will it cause significant collateral damage inside the gearcase?
3) Can I find a just a used pinion gear and replace the broken one, or do I need to replace the pinion gear and the forward and reverse gears as well?
4) How big a job is replaceing what needs to be replaced?

Thanks for taking the time to help an outboard newbie through the teething process (pardon the bad pun!)

Mitch

1. Not recommended, Probably
2. I think so
3. If one is that bad I am sure it wasn't good for the others probably should look at replacing them too.
4. I haven't done this my self, but with the help of a good manual I belive it could be done by most with the will and some mechanical ability.

Of course this is all just my opinion I am sure there is someone else that might think differently. There are many others on this site with much more experience than I. Good Luck

 

[Joe Reeves]

Re: Evinrude 40 HP (1973) Pinion Gear Problem

The pinion gear can be purchased seperately if you can find one. It is currently listed as being unavailable. The part number is 317336 and I suspose that someone still has one sitting on their shelf somewhere.

With that gear damaged, take a real good look at the other gears for damaged chipped teeth. If damaged, they will require replacing also.

It would probably be cheaper to locate a good used lower unit BUT check around for the parts first.

1 - Yes, it will self destruct.

2 - Yes, it will tear up everything else in the gearcase.

3 - Answered above.

4 - Fairly easy BUT use a manual to avoid common mistakes.

 

[jl_photo]

Re: Evinrude 40 HP (1973) Pinion Gear Problem

If you end up purchasing a used lower unit, i might like to buy the drive shaft if it is a short shaft.

or if you want a longer motor I have a 5 inch extension with matching shift arm and drive shaft to trade.

you might search for that part number on " dogpile.com "

carefully check all of the other components. that gear did not damage itself, it takes 2.