Starter gear replacement or repair

[Craiger]

I have a 1981 10hp Briggs engine on a Craftsman 36" tractor I've got apart to replace points and condenser system with solid state. I noticed the plastic starter gear P/N 280104 teeth are worn. Several teeth are not just worn but have chipped teeth corners where they engage the ring gear. There is from 1/16" to at worst 1/8" chipping. the engine was starting normally.

I removed the gear and inspection shows that both sides of the gear appear almost identical. Some repair videos say this gear has different sides. Mine sure don't look different. Is there any reason I shouldn't flip the gear over to have the unworn side of the teeth to engage the ring gear rather than ordering a new gear?

 

[mechanic mark]

If pitch etc. of gear look identical give it a try & let us know how it goes, thanks, Mark.

 

[StarTech]

Well for me I would replace the $2 gear but of course I get them direct from Rotary under PN 860 (pkg of 10). Even at $3 (PN 10860) I would replace it. The gear would be worn overall. Also if you don't have the tool for replacing the ring it is going to be a royal pain to get it on. It bad enough that the removal tool is on longer available which makes it a pain to get them off easily.

 

[Craiger]

If pitch etc. of gear look identical give it a try & let us know how it goes, thanks, Mark.

Not sure what you mean Mark by the pitch being the same. It fits on the plastic armature spiral exactly the same when flipped over. This would be like taking a threaded rod and flipping it end for end. It will still thread properly into a nut of the proper size. Since I posted this question I've viewed all the info I can find online which included about 7 or 8 videos. One pointed out the gear teeth on the top side which engage with flywheel ring gear are beveled for smoother engagement. Now that I looked more closely at my orig. gear this seems to be the case although it's hard to tell because the top side of the teeth are badly worn from over 40 years of use. The side of the teeth on the bottom which were not engaging with ring gear have sharp, square edges so that side might not engage as smoothly. Stay tuned for more developments.

 

[Craiger]

Well for me I would replace the $2 gear but of course I get them direct from Rotary under PN 860 (pkg of 10). Even at $3 (PN 10860) I would replace it. The gear would be worn overall. Also if you don't have the tool for replacing the ring it is going to be a royal pain to get it on. It bad enough that the removal tool is on longer available which makes it a pain to get them off easily.

There are three different Briggs & Stratton pinion gear designs. You mention a $2 price but the best price I can find for a single gear was about $7. I sure don't need 10. The price was not my objection, I have all the parts I need to get the tractor back running today and put away in winter storage so I didn't want to wait to order a new starter gear. What you are talking about with the "C" clip retainer is not what I have. Mine has a metal collar on the end of the starter shaft held on by a roll pin. No "C" clip which as you say can be a bear to remove and replace without the expensive, no longer available Briggs factory tool. My experience is you need boatloads of patience and several tiny screwdrivers to carefully remove or replace those little "C" clips. Also, gawd forbid when removing if it jumps away and it flies across the messy shop. Good luck finding it LOL. Out of curiousity I looked online and the tool may be still available from other sellers but it's very pricey at over $70. Not practical for one time use. Back to my engine, don't have to worry about that "C" clip thank goodness.

 

[StarTech]

Ahhh the very old design of keeping the assembly together.

I was referring to my shop's cost not the retail price. The Briggs OEM gear itself costs me 4.15 ea. But here a list of the supersedes for the 280104 gear and three of the alternatives.