My Monster'ed Hyper 7

[sleebus.jones]

Originally Posted by bdebde

A couple runs ate up a century pinion on mine. Gotta go with the ones from Mike, they really hold up well.

Well, that just kinda sucks. Looks like I'll be placing an order with Mike real soon.

Originally Posted by tc3_racer_001

are you running a metal spur? how long do the both gears last, metal on metal? id upgrade to the kyosho but if they last ages i may just not. but then again, the metal ones are noisy as!

Yes, I'm running a hardened metal spur. Metal-on-metal is supposed to last a long time, that's what a nitro buggy uses: metal clutch bell and metal spur.

Do NOT fall for the Kyosho plastic spur hype. I did, and found out that it didn't work for crap. In the H7, yes the kyosho spur will screw on, but it does NOT seal. So, if you don't mind slinging diff oil everywhere, go for it. I tried to come up with a nice neat seal solution, and what I tried did not work. I have heard of some folks having luck with using several paper gaskets, I did not try that. Also, the recess for the shaft o-ring is too shallow, and that tears up the o-ring in short order. Even if you get it all set, it doesn't spin as free (I'm assuming from the extra friction from the shaft seal) so that makes your diff oil choices kinda weird. I just didn't like it at all. Getting a hardened (or "hardened" in my case) pinion is the most trouble-free solution IMHO.

Originally Posted by bdebde

Yes, running metal spur. Been running for a couple months (couple runs a week avg.) with the same ones and they show little signs of wear. The metal gears are noisy, but my Muggy has enough power (and weight) to tear up plastic spurs in a hurry. I like the plastic ones, my buggy is nearly silent running one.

That is really good to hear. I don't find them to be too terribly noisy, but I agree the plastic spur is eerily silent. I wish I could run them also, but I too blasted teeth off of mine pretty quickly.

Originally Posted by lincpimp

Century pinions are not hardened. I even tried heating them up and quenching in oil and that did nothing. Now that you can get the rr gears (same as mikes) there is no point to run the century, unless you run plastic spurs. I run kyosho plastic spurs on all of my buggies and have not had any issues. They do not last as long as the steel spurs, but I hate the metal to metal noise. Plus the teeth do not really wear. It wears where the output shaft comes out of the platic spur, wish it had a metal insert.

Well, I gotta agree with you on the "not hardened" bit, even tho tower sez:

Originally Posted by towerhobbies.com

FEATURES: Hardened steel construction
1.0 Mod pitch

I was going to do the heat up/quench bit. Just curious, did you use new or old motor oil? Also, did you do a final quench in ice water? My main problem with plastic (if it fit) would be that I have a tendency to knock teeth off. Probably my driving (and I use that term loosely) style. Probably that hitting the ground at full throttle thing.

[xcntrk]

Originally Posted by sleebus.jones

I have heard of some folks having luck with using several paper gaskets

I would refrain from doing that. I just destroyed the internals of my center diff and it’s believed multiple (2) paper gaskets were to blame; by spacing the bevel gear too far away from the spider-gear assembly resulting on the teeth only making contact at the very end of the tooth surface. Combine that with BL torque and it only takes one tooth-jump to begin rounding the surfaces of all the gear teeth.