Lumikko
RCTalk Champion
Military Veteran
- Messages
- 201
- Reaction score
- 234
The pinion is too deep on the motor shaft and it has scraped the motor mount already.
To do it right and prevent future problems, go thru these steps:
1) remove pinion and the pinion grub screw entirely
2) clean the shaft, grub screw, and pinion inside out with acetone, isopropyl alcohol, or similar
3) add a bit of blue loctite to the grub screw and turn it back and forth in the pinion to get it over all threads
4) add some loctite inside the pinion and on the motor shaft as well
5) install pinion on the shaft far enough that the teeth align with the center diff
Use a high-quality ground hex driver and a new grub screw so you can tighten it without stripping the hex.
The motor mount looks scored and worn under the motor screw head. It’s possible that it has ”indexed” a certain gear mesh setting and slips into that even if you adjust otherwise. See if you can make it a bit smoother somehow, consider adding a washer if it fits in the groove.
If you have a hard time with the piece of paper, just throw it in the bin and adjust the gear mesh like so: push the pinion and spur together, back out a hair, and tighten the motor screws. If you can feel even the slightest backlash when you hold the pinion and rock the spur gear, the mesh is large enough. The goal is to make it as small as possible. Rotate the spur gear into various positions when checking the results because they are never perfectly round.
To do it right and prevent future problems, go thru these steps:
1) remove pinion and the pinion grub screw entirely
2) clean the shaft, grub screw, and pinion inside out with acetone, isopropyl alcohol, or similar
3) add a bit of blue loctite to the grub screw and turn it back and forth in the pinion to get it over all threads
4) add some loctite inside the pinion and on the motor shaft as well
5) install pinion on the shaft far enough that the teeth align with the center diff
Use a high-quality ground hex driver and a new grub screw so you can tighten it without stripping the hex.
The motor mount looks scored and worn under the motor screw head. It’s possible that it has ”indexed” a certain gear mesh setting and slips into that even if you adjust otherwise. See if you can make it a bit smoother somehow, consider adding a washer if it fits in the groove.
If you have a hard time with the piece of paper, just throw it in the bin and adjust the gear mesh like so: push the pinion and spur together, back out a hair, and tighten the motor screws. If you can feel even the slightest backlash when you hold the pinion and rock the spur gear, the mesh is large enough. The goal is to make it as small as possible. Rotate the spur gear into various positions when checking the results because they are never perfectly round.
