JohnP2

Hey guys, is it a best pracrtice to change both spur and pinion together? just changed the spur gear during a rebuild. The pinion was fine (although I have an extra), This got me wondering though if there is a seating process that should take place . Specifically between plastic sput and steel pinion. I've found that many parts to these wonderful machines work best when they seat together from day one (and it's best to change both while changing one)....I'm curious of this is one instance.

Thanks!

Anthoop

If the teeth are worn then replace it.....if not then no need.
When meshing the gears always check throughout a whole rotation of the spur at least....mesh should not need readjusting after a break in period (so to speak) unless you did something wrong.....but checking the mesh regulary does no harm.

Ybenjulkay2x

if your not sure how much your gear mesh, use the paper technique.

Hydro51

That's what i do to set the gear mesh on my nitro buggy and it works great for me.

flatpickhippster

Whenever I do any maintenance that involves having to re-align/mesh the pinion/clutch bell with the spur, I take a
felt tipped marker (Like a red Sharpie) and mark all the teeth/grooves on the pinion/clutch before reinstalling.

I set mesh using paper technique. Manually spin gears....The gears wear off the red ink and the wear pattern shows any irregular or misaliigne wear patterns. This allows me to see and correct any misalignments. If the ink does not wear off evenly across the gear.....then I correct as needed.

YMMV
Good Luck

JohnP2

Thanks, guys.I apologize asI amfamiliar with setting gear mesh - and actually quite picky about it.. Sorry I was not more clear with my question.

Instead I was wondering about seatingamesh (if there is such a concept). So much like you would replacing certain clutch shoe/bell setups, breaking in new diffs, etc. ;-) Based on the responses though - it sounds like there is no advantage to replacing them together.

p.s. FWIW, paper technique not needed for gear mesh. Just feel for that litle tick between the gears. Small as play as possible, but there should be play. Gears should be near silent when you roll the car. Go by what you feel hear. Better than relying on the paper. ;-)

flatpickhippster

Hearing ticks/going by feel does gets the job done for many, but for a beginner or at a noisy track or racer tuning an engine next to you in race garage......the paper technique is a good starting point. Its a safe tolerance and allows for what little heat expansion of gears and binding issues on long heated runs that might come from a too tight mesh. Like JohnP2 sez....there should be play. Fine tuning is always a good thing, but sometimes ya gotta tighten and play!!

JohnP2

Yeah, we agree. I'm saying that feeling that tick should be the first thing a beginner learns (don't think that is"fine tuning") youjust runtheriskof being shredded.

You should not even need to look at it. Relying on paper slows the process down if you are running multiple engines (some can be a PIA to get paper in to, etc)...you have to find some paper, cut it, etc. for each one.However, once you understand what a good gear mesh feels" like, it's like riding a bike.I'm sure you know that.

Dads like rc too

John, personally a good inspection of the two gears will tell the story. Since I know you have enough experience mechanically, it should be easy. On the models we have with brass pinions, I tend to replace them often without having to replace the plastic spur. I usually replace them prematurely since the pinion is like a two minute procedure compared to removing the center drive to replace the spur. On my stuff with metal to metal gears, I find if one is worn the other is not far behind upon close visual inspection.

nitroexpress

Who uses brass pinions?