Gear Box Grinding Noise

[dj_prit1]

please can someone help me
i have a horizon amp buggy its amazing fast love it
but i have been having problems with drive train, when u hold the wheels there is a grinding nooise from the gear box area as the motor is spinning but that happans when im driving the car
i havent got full power as i should.... can someone please help thinking of chaging the gears to metal ones ecx9001 will that help the problem

 

[i_r_beej]

Difficult to tell from your description.

First, remove the gear cover and check the mesh between the motor pinion and spur. There should be just the tiniest bit of play between the two gears. Too much play and the gears can skip and become damaged, too little (or none) and there will be too much friction, lots of noise, and a loss of power. Here's a link to the ECX Circuit manual. Go to page 9 for a description of how to set (and check) proper gear mesh.

Then check to make sure there is no debris caught between the drive shafts and suspension arms. When you lift the car up off the ground, apply throttle slowly and gradually. Do both wheels start to spin at the same time? Bring it up to full throttle and release. Do both wheels coast the same amount of time? If the wheels do not spin evenly, that indicates that something is binding one of the driveshafts. If you don't spot any debris (gravel, dirt, foreign objects) maybe one of the bearings are corroded or contaminated and thus can't spin freely.

At this point, if you are still detecting a grinding noise, open up the gearbox and inspect the gears. It may be the idler (between the topshaft/input shaft) and the differential may have skipped and damaged the other gears. At this point replace the gears. The metal gear upgrade would be a good, durable option. Just brush a little (just a little!) grease on the gears when you reassemble.

Here's a good video showing the disassembly of an ECX 2WD transmission (In this case a 2WD Torment) and the installation of the metal gear set.https://youtu.be/28IRxbvnKD8?t=5m54s

 

[Briguy]

Also check the tension of your slipper clutch. That can make a grinding sound.