How To - Clean and Maintain the Roller Clutch (One-Way Bearing)
Article #542533

One-way bearing maintenance for Traxxas EZ-Start® and pullstarter


If proper maintenance is not performed on the one-way bearing located in the starter system, a couple of problems can occur. The bearing can become gummed up with caster oil, and other lubricants from the unburned model fuel that makes its way through the starter shaft bearing and into the one-way bearing. This will cause the one-way bearing to slip on the starter shaft keeping the engine from turning over. It is also possible for the bearing to lack sufficient lubrication between itself and the starter shaft causing the bearing to over heat and lock-up onto the shaft. If the bearing is siezed onto the starter shaft, it will require that the shaft and bearing be replaced. These parts are available at local hobby shops nationwide. Locate a dealer near you!

Purchase part number:
5211R to replace the bearing on 2.5 and 3.3 engines.
5277 to replace the starter shaft on 2.5 and 3.3 engines.
5274 to replace the starter backplate on 2.5 and 3.3 engines
4011 to replace the bearing on Pro .15 engines
4077 to replace the starter shaft on Pro .15 engines

The maintenance steps below will help insure troublefree operation.


Remove the one-way bearing

TRXPro15 TRX2.5R

STEP 1: Note that on some models, the rubber exhaust pipe will require removal in order to gain access to the EZ-Start® mechanism. you’ll need to remove the engine from the Revo, Nitro Vee, and all nitro Maxx truck models in order to access the EZ-Start®. Remove the EZ-Start® by loosening the three 3x8mm round head machine screws that thread into the engine back plate. Next, remove the one-way bearing, but first take note at the way the bearing is installed. The text located on one side of the bearing must face the engine case when installed onto the starter shaft.


Clean the one-way bearing & starter shaft


STEP 2: Clean the engine’s starter shaft with a rag. Make sure to remove all of the oil deposits from the shaft and the EZ-Start® back plate. Check to make sure that the starter shaft is smooth (like the one in the photo). If there are any scratches or grooves in the shaft, it should be replaced, or damaged can occur to the one-way bearing as well.

STEP 3: Thoroughly clean the one-way bearing with denatured alcohol, or an electric motor designed for electric RC model cars. Set the one-way bearing on a paper towel and let it dry before reinstalling it on the starter shaft.


Lube & reinstall one-way bearing

Step 4: Lubricate the roller clutch with a few drops of Mobil 1 5W-30 synthetic motor oil, and place it onto the starter shaft. You may now reattach the EZ-Start® mechanism.


Note: The one-way bearing MUST be installed with the text (shown in picture) facing the engine case for proper performance. Once installed onto the starter shaft, the bearing should spin freely counter-clockwise, and engage the shaft when turned clockwise.


If after cleaning and relubing the one-way bearing, it still does not engage the starter shaft, then the starter shaft and/or one-way bearing will need to be replaced. We recommend replacing both at the same time for best performance, as they wear together during their operation.