Big Rock I think I need a Pinion Gear Upgrade

[Camreno]

So today for about 5 minutes with some light bashing on the new Badland MX38 Belted tires this happened...

I have a hard time believing that slightly bigger/heavier tires would do this under moderate load and only a few minutes but I'm too new to know for sure.

My guess is I didn't have it seated all the way in.

My real question is where can I get a good upgrade for the pinion and the center diff gear because all I'm finding is stock parts.

Also would you recommend going higher or lower with the bigger tires? Sock is 13T All I do is off road, barely any jumping

And lastly what is the tool called to get off that little clip holding the pinion on?

 

[Hector_Fisher]

Very possibly cause by bad gear mesh. But Arrma metal isnt the highest quality, so it may not be entirely your fault.

Many different brands of opinions to choose from. Tekno and robinson racing hardened pinions are the ones I've gone with before. I know there are several others, maybe you'll get more folks to chime in about that.

I'd personally stay at stock pinion teeth and monitor temps. You've already effectively geared up with the bigger tires, I'd try it at 13t and monitor temps.

As far as the E-clip, I use a flat head screwdriver and pliers, but there probably is an actual tool for that.

How's your center diff spur look...?

 

[Camreno]

Very possibly cause by bad gear mesh. But Arrma metal isnt the highest quality, so it may not be entirely your fault.

Many different brands of opinions to choose from. Tekno and robinson racing hardened pinions are the ones I've gone with before. I know there are several others, maybe you'll get more folks to chime in about that.

I'd personally stay at stock pinion teeth and monitor temps. You've already effectively geared up with the bigger tires, I'd try it at 13t and monitor temps.

As far as the E-clip, I use a flat head screwdriver and pliers, but there probably is an actual tool for that.

How's your center diff spur look...?

I need to replace that as well, it's not as bad but its a little grinded. I was looking at tenko but don't know which will fit. Does this look right?

https://www.teknorc.com/shop/tkr4173-m5-pinion-gear-13t-mod1-5mm-bore-m5-set-screw/

 

[Saladshooter]

I need to replace that as well, it's not as bad but its a little grinded. I was looking at tenko but don't know which will fit. Does this look right?

https://www.teknorc.com/shop/tkr4173-m5-pinion-gear-13t-mod1-5mm-bore-m5-set-screw/

That one should do the trick.... If you do Amazon they have it in stock and it can be had cheaper & faster. About $14 total.

 

[trexdd]

While you have it apart, it would be a good time to replace the motor screws with something more durable than the Arrma ones.

 

[Camreno]

While you have it apart, it would be a good time to replace the motor screws with something more durable than the Arrma ones.

Any recommendation? I'm actually having trouble getting one of them out lol

 

[dure16]

The issue was mostly caused by loose gear mesh IMO. You can see how only the outer part of the gear is ruined. The gears should have been closer together.

Tekno pinions are some of the best though.

 

[Littlemotor]

As stated above; Tekno Mod 1 allllllll day.. be sure to use Loctite on any fastener going into metal, and let cure over night if it’s not the paste. As for the Jesus clip-a small flathead, or a pair of needle nose. I throw them in the trash. It’s only there in case your set screw fails, and I haven’t had that happen in 30yrs when it’s been my work. Because I said that, it’ll probably happen tomorrow.

 

[Tex Koder]

Any recommendation? I'm actually having trouble getting one of them out lol

You need to apply heat to that stuck motor mount screws Before attempting to remove them..
Don't risk stripping it.

 

[Littlemotor]

You need to apply heat to that stuck motor mount screws Before attempting to remove them..
Don't risk stripping it.

Beat me to it. And a quality driver, with good engagement.

 

[Camreno]

The issue was mostly caused by loose gear mesh IMO. You can see how only the outer part of the gear is ruined. The gears should have been closer together.

Tekno pinions are some of the best though.

Yeah I assumed it wasnt set right although I wasn't able to push it together anymore, I'll be more mindful next time! Tekno ordred

 

[trexdd]

Yeah I assumed it wasnt set right although I wasn't able to push it together anymore, I'll be more mindful next time! Tekno ordred

You don’t want to push the gears together tightly. They need a correct mesh, which allows some play between the pinion and spur gear.

Like @Tex Koder and @Littlemotor said, heat and a good quality driver for removing old ones.

 

[Camreno]

You don’t want to push the gears together tightly. They need a correct mesh, which allows some play between the pinion and spur gear.

Like @Tex Koder and @Littlemotor said, heat and a good quality driver for removing old ones.

Yes now I know haha

 

[lee82gx]

Any recommendation? I'm actually having trouble getting one of them out lol

May I know how is it that you managed to photo the motor mount slider with both screws already out, and then still having trouble with them "getting one of them out" again...??

Anyway the pinions stripping is so damn common....I've started a thread too. Those 2 darned screws are just not working well. I have replaced them with M4x18 socket head 12.9. I use GREEN LOCTITE but you really need to let it cure, whichever one you use. I suspect that like me, your motor mount slider got loose but the screw is still tightly threaded on purely due to the loctite. A nightmare.

 

[NitroK]

So today for about 5 minutes with some light bashing on the new Badland MX38 Belted tires this happened...

View attachment 354007


I have a hard time believing that slightly bigger/heavier tires would do this under moderate load and only a few minutes but I'm too new to know for sure.

My guess is I didn't have it seated all the way in.

My real question is where can I get a good upgrade for the pinion and the center diff gear because all I'm finding is stock parts.

Also would you recommend going higher or lower with the bigger tires? Sock is 13T All I do is off road, barely any jumping

And lastly what is the tool called to get off that little clip holding the pinion on?

If you want stock setup with new tyres;

New pinion size = (New tire diameter / Old tire diameter) x stock pinion

 

[hobo]

I use hpi mod 1 pinion gears for years. as said above the tekno pinion gears are better cause you get the bigger grub screw, there just a bit expensive in the uk for me

 

[Camreno]

May I know how is it that you managed to photo the motor mount slider with both screws already out, and then still having trouble with them "getting one of them out" again...??

Anyway the pinions stripping is so damn common....I've started a thread too. Those 2 darned screws are just not working well. I have replaced them with M4x18 socket head 12.9. I use GREEN LOCTITE but you really need to let it cure, whichever one you use. I suspect that like me, your motor mount slider got loose but the screw is still tightly threaded on purely due to the loctite. A nightmare.

Okay then not the motor mount screws but the 2 screws that hold the aluminum plate on to the motor behind the pinion gear.

And yeah it seems like a pretty poor design. I ordered new pinions, new center diff, and titanium motor mount screws, will blue lock tight and hope it does the trick. I was looking at getting the gear mesh mount by hot racing but I think I've spent enough lol

I use hpi mod 1 pinion gears for years. as said above the tekno pinion gears are better cause you get the bigger grub screw, there just a bit expensive in the uk for me

I picked up a Robison 13t and a tekno 14t on Amazon for cheap

 

[Littlemotor]

Okay then not the motor mount screws but the 2 screws that hold the aluminum plate on to the motor behind the pinion gear.

And yeah it seems like a pretty poor design. I ordered new pinions, new center diff, and titanium motor mount screws, will blue lock tight and hope it does the trick. I was looking at getting the gear mesh mount by hot racing but I think I've spent enough lol


I picked up a Robison 13t and a tekno 14t on Amazon for cheap

I’d highly advise against Ti MM screws. 12.9 factory replacements are plenty. I’m aware that most folks here prefer button heads to get away from the flat head factory screws for the MM slide fasteners, but I’m not on board with that, myself.

 

[Camreno]

I’d highly advise against Ti MM screws. 12.9 factory replacements are plenty. I’m aware that most folks here prefer button heads to get away from the flat head factory screws for the MM slide fasteners, but I’m not on board with that, myself.

Factory ones are horrible, I had to use a screw extractor to get the first one out, I didn't even tighten it hard or use any thread lock

 

[Littlemotor]

Factory ones are horrible, I had to use a screw extractor to get the first one out, I didn't even tighten it hard or use any thread lock

Ok, good luck.