Pro gear users please step in

[40Coupe]

I recently installed a new set of Pro Gears in my 12-bolt. I spent a fair amount of time prepping the gear set. I profiled all of the leading/trailing edges on the ring and pinion, bead blasted the set, used the recommended GL6 synthetic lubricant, set the backlash a little on the tight side (.008 vs. .010 spec) and setup the pattern to favor the toe of the ring gear. I also run an LPW support cover. The housing is a Moser with beefier caps and larger cap bolts.

I made a few passes last night and the set has a slight noise/howl on decel which I understand is normal when you setup a gear set to favor the toe. Today I drained the lubricant and pulled the cover to inspect the gears. There is a nice shiny pattern with no signs of galling/scoring but I did end up with fair amount of "molly" looking wear particals in the bottom of the case.

Would this describe normal wear for a pro gear? I realize the metal is softer to absorb shock which would lead me to believe this wear is normal. Thoughts anyone?

[Run to Rund]

I am running 4.86 pro gears in a 9" and they are quiet. Yours should be too. Did you blast the wear surfaces of the teeth (I hope not)? Since on setup you can't get a real load on the teeth, the pattern on the drive side should be toward the toe but not run off the end of the ring gear teeth.

[40Coupe]

I talked to tech at Richmond today and they said button it up and run it. Everything I described is normal. He said 12-bolt gears especially will make some noise on coast. The teeth apparently "lay over" slightly after the first pass and create some coast side interference.

Yes, I used a very fine abrasive in my blast cabinet to remove the coating. I was told that the black coating would quickly wear off and becomes an abrasive inside the housing.

[67ss]

I think you are ok. Richmond told me the same thing a while back, but my gears had started getting noticeably louder. Ended up pulling them and found all teeth on pinion to be cracked. But this was after about 4-5 years of service. They just started getting louder this season. Richmond said you will find something when you pull them and I did. They said the new set may develop a slight noise after a few passes but not get any louder. Just as they said the new set developed a slight noise after the first few passes but that is all. I will know now once the noise changes and starts getting louder what is going on.

[Mike Pearson]

There is really no reason to run a pro gear unless you are running a manual trans. You will get better gear life from a heat treated gear. I only run a pro gear in my car because the ratio I use is only available in a pro gear. The 488 gear is very strong. You dont need a pro gear. It will save a few bucks also. The reason the teeth take a set is because of the soft alloy of the steel. They also wear much faster.

[ericsz]

Just my one brush with Richmond Tech makes me wonder about their knowledge, They told me to set my street gear up with as close to ZERO lash as possible so I did, it lasted 10 passes. Re installed another street gear at approx .012 and has over 200 passes on it. As for pro gears the only one I ever used was marked .008 so I installed it .010 and it did just fine. Just my 2 cents. I use the Red Line Shock resistant lube too.

[Jim Kaekel]

No disrespect intended Mike, but there are applications that do require a "pro" gear, particularly those that are high HP or heavy. I used to run a "street" gear in my '70 Olds (3770 lbs.) that has a 12-bolt, but changed to a "pro" gear after a couple of failures and recommendations from Mark Williams. Naturally, a "pro" gear doesn't have the service life of a "street" gear, but it sure beats being towed off the track. Sure, a "pro" gear is more expensive, but most of the time when a gear set fails, it takes the transmission right along with it. P.S. - Mine also has a very slight noise on coast that you can hear when the motor is shut off.

[Run to Rund]

If you want to go "in between", Quick Performance got some 9" pro gears made up with "street" i.e. harder heat treat so they last longer.

[40Coupe]

Thanks to all who responded. Jim- I'm where you are. I certainly prefer to have a bit of insurance with the pro gear.

[Chris Hill]

Just curious, but what is the metrology and surface treatment difference between a "street" and a "pro" gear. I know the gear guys for over the road transmissions really like a 8620 gear with a carburized surface. Gives the "tootsie roll" effect. Hard on the outside with soft gooey center .