3120 Oil Pump Drive Alternative?

[Up A Creek]

I need the plastic "wheel" between the Husky 3120 brass oil pump drive gear and the clutch drum.
OEM part 503 89 62-01 is the brass gear and the plastic wheel together and is almost $100. Most of that has to be the brass gear. All I need is the plastic wheel.
Is there somewhere I can get just the plastic wheel? Aftermarket?

 

[Up A Creek]

When I first looked nothing popped up.
Did some more research. Proline and Farmertech make sets.
If I needed the brass gear I'd probably swallow the cost and buy OEM. Since I only need the plastic I ordered a Proline (Farmertec had to come all the way from China).

For the next guy.

 

[RedneckChainsawRepair]

I've never tried a afm one. set $9 and shipping https://www.farmertec.com/Worm-For-...insaw-Replaces-OEM-503-89-62-01-p1063692.html

Shipping showed $5 but it will take a bit by E-pack.

 

[RedneckChainsawRepair]

Another aftermarket sold by dealer in TX. So would be quicker at $30 plus ship. https://www.ebay.com/itm/2252620854...0t7tQz64o9JQxWMdtW4Rh7NDOE6J|tkp:BFBMpIisi-Nh

 

[RedneckChainsawRepair]

OEM 67 shipped and seller I have bought alot from over the years. https://www.ebay.com/itm/1449769237...onKWq6XXqVu025Arx8GUjTOM5bsa|tkp:BFBMpIisi-Nh

 

[Up A Creek]

Thanks man.
I actually found the first two. The OEM one didn't pop up in my search. Maybe cause I had dashes in my part number.
I've ordered from them before too. I may order that in case my aftermarket one doesn't work.

 

[Up A Creek]

I got the Proline in and as I figured the metal is lower quality. OEM is a brass alloy. Non magnetic whatsoever. The Proline has enough steel to be slightly magnetic. I can't pick it completely up but one side comes up.
Also the machining is very slightly rough. You can see in the pictures very small "chips" in the apex of the teeth. Combined with the harder (steel) alloy would make me worry about the longevity of the gear it's meshing with (I'm assuming it's brass as well but I haven't confirmed). It wouldn't go bad right away, but I would imagine the harder alloy and slightly rougher surface taking it's toll on the driven gear long term.

The plastic is slightly different too. There's an extra standoff portion on the OEM that I assume is to hold the rim sprocket up against the clutch drum so it stays lined up with the bar. I don't know exactly what it looks like because my chain ate it up.
Potentially may be better off with OEM even just for the plastic portion. I ordered an OEM one, so we'll see what that looks like when it comes in.

Proline on the left and OEM on the right.

 

[RedneckChainsawRepair]

Long as they work is all that matters to me.

Heck Farmertec did a brass worm gear in their G395. When it goes out I am just going to put a oem or afm plastic one back in.

 

[Jacob J.]

I got the Proline in and as I figured the metal is lower quality. OEM is a brass alloy. Non magnetic whatsoever. The Proline has enough steel to be slightly magnetic. I can't pick it completely up but one side comes up.
Also the machining is very slightly rough. You can see in the pictures very small "chips" in the apex of the teeth. Combined with the harder (steel) alloy would make me worry about the longevity of the gear it's meshing with (I'm assuming it's brass as well but I haven't confirmed). It wouldn't go bad right away, but I would imagine the harder alloy and slightly rougher surface taking it's toll on the driven gear long term.

The plastic is slightly different too. There's an extra standoff portion on the OEM that I assume is to hold the rim sprocket up against the clutch drum so it stays lined up with the bar. I don't know exactly what it looks like because my chain ate it up.
Potentially may be better off with OEM even just for the plastic portion. I ordered an OEM one, so we'll see what that looks like when it comes in.

Proline on the left and OEM on the right.

I've never seen a brass oil pump gear in an OEM oil pump assembly. I know that every 3120 oiler I've worked on had a hardened tool steel
pump gear. They couldn't make it out of brass and expect it last for any length of time.

Making the worm gear out of brass is acceptable because it's under a different load and stress.

 

[Up A Creek]

I've never seen a brass oil pump gear in an OEM oil pump assembly. I know that every 3120 oiler I've worked on had a hardened tool steel
pump gear. They couldn't make it out of brass and expect it last for any length of time.

Making the worm gear out of brass is acceptable because it's under a different load and stress.

The worm gear would be the actual oil pump gear? The one inside the saw.
The gear on the crankshaft (the one in the picture) isn't a worm gear.

I don't know what's inside, like I said, I didn't take a look.
I do know they would only use brass if there was a reason/advantage. It's considerably more expensive than steel even if it is easier to machine. It's usually used if you want corrosion resistance or if you want one part to wear less since it's softer than steel.

AFAIK The gear on my crankshaft is original (I bought the saw brand new), and it's definitely some type of brass alloy. Or possibly bronze? Exactly how much I don't know. Either way it's definitely not steel.

Long as they work is all that matters to me.

Heck Farmertec did a brass worm gear in their G395. When it goes out I am just going to put a oem or afm plastic one back in.

It will work, I'm just leery of the long term effects on the oil pump gear. I would assume they used brass to wear less on the part. Plastic would be fin with me. Cheap if I had to replace it.
I don't need the gear itself anyways, just the plastic collar/flange.

I just figured I'd post this for anyone else interested.