Granite pinion gear

[Rummy12]

I'm upgrading my son's granite 4x4 to brushless. The stock pinion gear for brushless is a 15T and spur gear is 57T. I don't have a 15t pinion gear but I have a 13t pinion gear. Can I use this with the 57t spur gear or is this going to give me problems? Thanks

 

[jondilly1974]

I'm upgrading my son's granite 4x4 to brushless. The stock pinion gear for brushless is a 15T and spur gear is 57T. I don't have a 15t pinion gear but I have a 13t pinion gear. Can I use this with the 57t spur gear or is this going to give me problems? Thanks

Is it a 32p or 0.8 Mod pinion? If so, yes. They Mega gears are 48p and not compatible with the BLX gears.

 

[Rummy12]

Yeah Its 0.8 mod 13t pinion. I just don't want it to wreck my spur gear.

 

[jondilly1974]

Yeah Its 0.8 mod 13t pinion. I just don't want it to wreck my spur gear.

As long as they are both the same pitch you’re good to go ??

 

[Rummy12]

I'm stumped again. I changed all the gears to the same gears I have in my blx. My son's was a mega originally. Now its really jerky on take off and even when it gains some speed. I can't figure this thing out. If it I hold off the ground it's not jerky at all. Any suggestions?

 

[jondilly1974]

I'm stumped again. I changed all the gears to the same gears I have in my blx. My son's was a mega originally. Now its really jerky on take off and even when it gains some speed. I can't figure this thing out. If it I hold off the ground it's not jerky at all. Any suggestions?

Any chance you can post a link to a video? I’m thinking it may be the pinion mesh without any other info.

 

[Rummy12]

I gave up for the night! I'll try to post a video tomorrow. The granite has numbers on the motor mount for gear meshing and I have it mounted in the 13t position but I agree with you cuz I can't think of anything else it could be

 

[Rummy12]

I did some more research so please bare with me. I'm using an arrma 3800kv motor from one of my old trucks. This motor has the 3.2mm shaft which was too small for the 15t pinion that came in the mail today. This is why I stole the 13t off my old truck. After researching I do believe that 13t is 32dp but I could be wrong. The 3200kv motor on the new trucks has a 5mm shaft. I can't seem to find a 15t pinion that will fit the 3.2mm shaft. My brain is fried!! Maybe I'm overthinking this!

 

[Rummy12]

So today I swapped the whole motor assembly from my truck(which is still all factory) and put it in my son's truck. I still had the same result.(jerky on takeoff) I put his motor assembly in my truck and everything worked great. Im starting to think it's something in one or both of the diffs. This experiment eliminates the possibility of a poor pinion/spur mesh. Any idea why this is happening?

 

[jondilly1974]

Pull the center driveshaft to eliminate the front diff. Then swap diffs front to rear. Then run with the center again until you either identify or eliminate the diffs as the issue.

 

[Cheapbastard]

What esc is in your son's truck?

Other than something binding in the driveline the esc may not be able to handle the load (gearing). Swap your BLX100 esc into your son's truck and see what happens.

 

[Rummy12]

He has the blx 85 which he's been running since I swapped out the mega ecs and motor when he first got the truck. It's always worked fine until I starting upgrading gears. But, I'll still do what you suggested and see what happens
It's Same esc/motor combo he had in his old 2wd granite

 

[Cheapbastard]

60a (BLX85) vs 100a (BLX100). Get a higher amp esc and your son should be rockin' then IMHO. You can also get a 5mm to 3.175mm (1/8") adapter so you can use 5mm bore pinions with that 3800kv motor.

 

[Rummy12]

Pull the center driveshaft to eliminate the front diff. Then swap diffs front to rear. Then run with the center again until you either identify or eliminate the diffs as the issue.

Just got done with the swap. Same result. I haven't tried swapping the esc yet like Cheapbastard suggested. Do you think the esc could be the issue?

 

[jondilly1974]

Just got done with the swap. Same result. I haven't tried swapping the esc yet like Cheapbastard suggested. Do you think the esc could be the issue?

Can’t hurt to try ??‍

 

[Rummy12]

The esc it was!! Swapped it out with my blx100 and away it went. Thanks everyone for all the help. I was ready to give up!!