The first breakage of the Rival MT10 happened whilst jumping and landing funny on the rear wheels, I instantly knew that the spur gear was damaged due to the loss of drive and grinding noise that it started making. Considering how hard I use this truck I am suprised that this is the first time I have had to change this to be fair.
Parts used for this repair
You will also need some basic tools, I used the fastrax Hex driver set and also some small pliers.
The first thing to do is remove the 2 screws that are pictured just in fron of the rear shock tower as pictured below.
Then you need to turn the car over and remove the four screws at the rear of the chassis as shown in the image below.
Once you have removed these, the rear section of the chassis should pull apart, it may need a bit of a wiggle as it is a snug fit. ( Also be careful not to pull it to far if you have not disconnected the rear LED's as you may damage the wires )
As you can see the spur gear was indeed damaged and needed replacing, be sure to remove any debris or grit from the chassis and diff housing at this stage to avoid damage to the new spur gear when it's fitted.
At this stage it is also worth checking bearings to make sure they are not seized or collapsing, luckily mine just needed a bit of a clean!
Once you have the center diff removed you will need to remove the four screws holding the spur gear to the diff case.
Inspect the internal gear to ensure that they are not damaged in anyway.
The pliers make it easy to remove and refit the locating pin on the inside of the spur gear, It is also important to remember that the pin fits over the shim and the shim has a rubber O-ring underneath it to keap the oil in! Swap the bevel gear and outdrive onto the new spur gear and make sure you use the new seal included with spur gear even if the old seal look in good condition.
Once this is done then it is a simple job of puting the center diff back into the chassis and re-fitting the rear half of the chassis in the reverse order of disassembely.
After you have the model back together I highly recommend checking the mesh of the pinion and spur gear to ensure the motor has not moved during use, If you skip this step you risk the new spur gear becoming damaged prematurely.
And thats it! A nice and easy job ready to hit the dirt once again!
