I'm re-assembling my engine after a refresh. The bronze O/P drive gear has 0.020 backlash, so I need to replace it - again. It wouldn't bother me if this were a $30 part, but at $150 a pop, the costs add up! I'd appreciate any suggestions as to a longer-lasting gear or less-expensive alternative.

Go to 'for a bodies only' there is a big discussion about, 'melonized hardened gears'!

One gear is steel and the other is iron, then all you have to know is what your cam is 'made of' to get the right one?

Most billet cams are steel 'of course' and some factory rollers are iron based cores...

Do you run a collar on your distributor shaft? I installed one and it reduced the wear rate on my bronze gear dramatically by limiting the up and down movement of the gear.I was going to have my next gear cryogenicaly treated, but ended up using the melanized gear when i switched over to a new cam. I also installed a Milodon oil pump, which is claimed to take less power to spin at any given rpm.

I don't know if you can do it on a big block or not but on my small block I drilled a small hole in the plug at the end of the galley, that hole squirts pressurized oil directly on the gear. I don't know if this will help or not because its a recent modification but I am sure it can't hurt. It doesn't have to be a big hole at all. I don't recall the size I used but I tried a few different sizes and was alarmed at the volume of oil that came out while pre-oiling. IIRC I used the smallest drill bit that I could use with a hand drill going into steel.

Also running thinner oil helps work that gear less.

Is this what race roller cam guys are running now-a-days?
Crane distributor gear - LINK

Reading a lot about this issue while I wait for head gaskets. I have a milodon bronze gear, thinking I should buy the melanized gear instead, but has anyone run it with the MP hv pump? This drive gear issue worries me a bit, this engine will see -30 degree temperatures where even 5w30 flows like molasses, way more load on the drive gear at low temperatures.
I am going to fit the cam up and see what the gear mesh and lash are like.

That's what I'm running! Hundreds of dragstrip passes, over 7,000 miles and showing virtually no wear.

I'm running a collar. It helps keep my timing stable, but I'm not sure if it's helped with gear wear

Howard's sells just the gear (without the shaft) for $76.95.

Inexplicably, Howards uses the same marketing photograph as CAT uses.

The CAT part is $19.95, free shipping.

You have to press the gear off and on, yourself.

I wouldn't be super surprised to learn that not only is the marketing photograph the same, but the part itself just might be the same too.

I should probably buy them both and see.

The MP part used to be manufactured locally in Mt. Clemens MI, but I am not sure about nowadays, and the "made in" sticker might have only referred
to assembly and packaging....for all I know it may have had a $19.95 imported
gear on it all along.

Both the the Slant 6 and Chevy stovebolt cam drives appear to benefit by a pressure squirt directly to the mating surfaces.
I have a feeling (and no more than that) that the rotating gears' centrifugal force tends to spin off any splash oil, and more may decrease surface temperature.
Metering sizes: anything above .030" is supposed to be safer from debris floating in the oil which may block it.

Talk is cheap ... post a link !!

Put marking compound on the new one and look at the pattern. You can't move the bushing hole, but you can move the cam forward, or backwards, and the gear up or down. When it's all centered, you'll have way less play, and way less wear. No different than the diff

My used gear has 700+ passes on it. Looks fine.
Doug

What material, what oil pump?

I know this is AMC but it illustrates what lengths AMC went to when it came to lubricating the oil pump drive gear.

AMC Oiling Video

This accomplishes absolutely nothing on helical cut gears.The clearance is what it is. The only way to adjust clearance is with a gear that's cut oversize or undersize. And the same applies to straight-cut gears.

I trashed one with only 3k street miles and a couple strip passes. I was running 20W50 Brad Penn the whole time and never even thought about it. Was recommended, just like in this thread, that I check contact pattern on the new gear before running it. Haven't done that yet.

I saw one melonized gear used once on a solid roller....small block chevy, it put shattered hardened gear through out the engine, I'll never use one . my

\
Bonze gear. Indy single line pump cover with the Melling thick rotor pump. 5w20/30 JR1 synthetic. Cam endplay is controlled with a Jessel belt dive.
Doug

Maybe thrust has some thing to do with it I have a Milodon gear drive that sets thrust of the cam and the bronze gear in my 512 is sill in good shape too.