MRC Pro pinion problem

[toyotatrucks83]

I know Boneskid1 just posted something with this same question but I didn't see an answer. I'm having problems getting the pinion to fit on the motor shaft properly. I took some pictures just so I could be clear on what was happening.
In this picture this is the 14T pinion that comes with the MRC Pro kit.

This picture is an Associated 12T pinion. Same problem as the stock on.

Flipped the other way there is not enough shaft to lock the grub screw down on.

Just for reference here is how long the shaft is. 10mm.


I would like a 12T pinion. I don't know who makes one that will fit properly. Like in pictures one and two. There has to be a simple answer for this. What 12T pinion is everyone running?

[toyotatrucks83]

Also I have a 2445 brushless motor that I want to try out on this same transmission. It has a 3mm shaft. Anyone know what brand of pinion will fit that. 12T-15T is what I'd be looking for.

[Grimreeper]

what if you made a shim on the other side of the motor to push the motor away from the plate. that would give you the room to run the set screw on the motor side of the shaft and clear the spur.

[chino925]

-use washers are spacers behind the spur gear to space the spur farther away from the motor plate then that should fit.

-dremil the pinion shorter

-get a robinson racing pinion

-mount the pinion the other way

[Charlie-III]

Most people use a spacer between the motor & the motor plate. I made one out of 1/8" aluminum.
Some of the BL motors have a longer shaft, so it's not an issue, the brushed motors tend to have shorter shafts.
I just went through this on my MRC Pro & Reedy Stump Puller.

[toyotatrucks83]

With installing a spacer between the motor and the motor mounting plate creates other issues. First off screws are not long enough to mount motor through the spacer. Second the pinion is sunk down into the motor plate therefore needing some dremeling to clear the pinion.
I'm not knocking this method. I'm sure that is what I'll need to do. Why is this even an issue? I'm sure the rtr MRC that came with a brushed motor had a pinion that fit. I just thought there maybe a specific brand everyone one using. I did search the Robinson Racing page but could not find a 12t 2mm pinion.
I did see the LOSB1069 bag of pinions. But they are press ons.

[Getrag]

Originally Posted by toyotatrucks83

With installing a spacer between the motor and the motor mounting plate creates other issues. First off screws are not long enough to mount motor through the spacer. Second the pinion is sunk down into the motor plate therefore needing some dremeling to clear the pinion.
I'm not knocking this method. I'm sure that is what I'll need to do. Why is this even an issue? I'm sure the rtr MRC that came with a brushed motor had a pinion that fit. I just thought there maybe a specific brand everyone one using. I did search the Robinson Racing page but could not find a 12t 2mm pinion.
I did see the LOSB1069 bag of pinions. But they are press ons.

I used a stock Losi motor that comes with the Bind n Drive MRC on my new Pro and it fit fine. It seems like the problem is the motor shaft is too short on yours. Because the pinion is meant to be mounted with the grub screw at the the far end of the motor shaft and the gear closer in. This is probably good because it puts less stress on the motor shaft when the gear mesh is as close to the motor housing as possible.

I haven't had to try to deal with it though. Did you try to shim the spur gear out a bit like Chino suggested?

[AreCee]

Seems like it is a problem when trying to use a 370 motor instead of a 280 motor which is what is designed to use. The 280 size motor I installed fit perfectly pinion and all.

I looked at a 370 size and it would require quite a bit of motor plate mods.

[boneskid1]

i didnt post pics but what i did was grind the back of the stock pinion and it fits with out rubbing the spur gear i can try to post pics if anyone wants but i unfortunately don't have the tools to take the truck apart completely

[toyotatrucks83]

Originally Posted by boneskid1

i didnt post pics but what i did was grind the back of the stock pinion and it fits with out rubbing the spur gear i can try to post pics if anyone wants but i unfortunately don't have the tools to take the truck apart completely

Pictures would be great.

The 370 Fireball motor is what I had sitting on my desk at the time of the pictures. I have a 280 brushed motor with the same issue. I also have two 2030 brushless, two 2040 brushless, 2445 brushless, all with the same issue. They all have 10mm shaft lengths.
All the input here has been appreciated. I can mod this stuff up and make them all work. I was just looking for quick simple fix without tearing up the motor plate.

[redemon]

Get that BWD motor plate.
It fixes the issue I think

[boneskid1]

here are a few pics of what i could get but my apologies if they don't satisfy
here is where the pinion sits after grinding the back off

the back of the pinion sorry that you cant tell but it sits down on the shaft alot lower than it did before


also toyotatrucks83 i have a 13 tooth pinion that will fit with the mod but i don't know how well it works with this pinion because i have enough wheel speed and torque with the 14 tooth

[danhikeski]

How is the bearing on that end of your motor? The reason i ask is this, it looks like the bearing on your motor is outside the can, whereas the stock motor has it inside? Not sure if that is the case or not, i bet that is why the stock motor doesn't have this issue, look for a motor that has the bearing inside the motorcan or one of the other suggestions that were given here and the other post (grind and always carry an extra)

[boneskid1]

the bearing is one the outside on the fireball and the frenzy and i believe the insane is that way to but you are right the stock lmrc motor the bearing or busing is inside the motor can and that could be part of the reason we are having pinion problem the other problem is that the stock motors shaft is a lot longer as far i i can tell

[gac1983]

Here is what I did. The problem I had was the motor plate seemed to flex with the motor out that far from it.

I got a hh motor now it has a longer shaft.

[toyotatrucks83]

Thanks for the pictures. It is helping a ton. I'm sure more than just myself as well.

[ohdeeuhm]

Nice, looks like I need to make a spacer for my 370 motors. I have a MRC coming in the mail and a few 370's and a Tacon 2040 brushless.

I didn't know that the MRC was "meant" to use 280 sized motors. That's news to me.

[toyotatrucks83]

Originally Posted by ohdeeuhm

Nice, looks like I need to make a spacer for my 370 motors. I have a MRC coming in the mail and a few 370's and a Tacon 2040 brushless.

I didn't know that the MRC was "meant" to use 280 sized motors. That's news to me.

If you have one of the non finned 2040 tacons you need to enlarge the hole in the motor plate to except the front bearing on the motor. But it will mount in the existing screw holes. Also no problems with the pinion. I'm keeping the taconite motor in my son's because he can't drive slow anyways.