Grinding gears… Highlander RC, March 19, 2024March 19, 2024 You know what really grinds my gears? A bad gear mesh, that’s what… To be honest, this is the first time I’ve had a motor chew up the pinion and spur gear. Somehow, I haven’t destroyed any in my Traxxas Slash 2WD, which I’m really surprised at. Right, enough yabbering, lets get on with it… The whole process of removing the motor and main gearbox is actually relatively easy. Thankfully, FTX have designed the Hi-Rock in such a way that will allow you to do this reasonably quickly. They’ve also excluded exploded diagrams in the manual, along with all the part numbers next to each individual for easy reference. For easy reference, I have included links to the parts I have replaced. Please not, that I am not sponsored or endorsed by Modelsport, and that these parts will be available elsewhere. I have used Modelsport on multiple occasions, and they are my go to for RC spares in the UK. Other stores are available. FTX Outback Fury Pinion Gear 14t 48DP (FTX9183) – https://www.modelsport.co.uk/product/436669 FTX Outback Hi-Rock Main Spur Gear 81t (FTX9282) – https://www.modelsport.co.uk/product/447388 Disassembly To begin with, I first removed the battery tray. If you haven’t moved it to the centre position, then you won’t need to do this. As you will see from the image below, the battery tray gets in the way when trying to remove the whole motor assembly. Once that is out the way, there a a few other quick and easy steps you need to follow. Next up, disconnect the bullet plugs for the motor. Once you have done that, you will then need to cut the small cable tie holding the motor wires to the main chassis. Once you have done that, you will then need to remove the small cable brackets from either side of the chassis. They are opposite from each other, and look like the item circled below. With that done, it’s now time to move onto the motor mounts and half shaft. At the end closest to the gearbox, there is a small grub screw that you will need to undo to remove the half shaft. You only need to loosen this screw, and be careful not to lose it. Once it is loose, that end of the shaft should push back towards the centre transfer box, then slide out of the other end completely. Put this to one side for now. With the half shaft removed, there are three more screws to remove. After removing these, you will need to slide the whole assembly towards the rear of the vehicle to remove it, but be careful, it can be a bit fiddly. There are two screws on the front shock towers, and one that goes through the chassis. Below you will see an image of the screw on the right side… …and the other two on the left side. Make sure you put all of the removed screws in a safe place for the time being. With everything thing now out of the way, the whole assembly should come out, and you will be left with something like this… Gearbox & motor strip down As you will have probably seen in the image above, I replaced the 3 screws removed earlier, along with the half shaft. I’ve done this as I’m a hell of a man for misplacing things. Now…comes the fun part, and it’s surprisingly easy. Firstly, remove the dust cover from the front of the motor. That’s the little plastic piece with the spider on it. It is held in place with one screw. With that out the way, the next step is to remove the motor. There are two set screws either side of the motor shaft. Remove these. Now that the motor is out the way, it’s time to remove the motor mounting plate. This is held on by three screws, which can be easily seen below. Once you have removed the 3 screws, the plate will lift away, revealing the spur gear and slipper clutch setup. Now you will need to carefully remove the retaining nut for the slipper clutch. Slipper clutch assembly Please make sure you do not lose this nut, or the spring underneath it. With this out the way, the top slipper plate should come away nicely. This will leave behind the spur gear, with the slipper plate sat inside it. I forgot to take a picture at this point, hence why the picture below has the slipper pad inserted into the new spur gear. Carefully remove the old spur gear and the remaining parts of the slipper clutch. At this point, it’s a good idea to give everything a quick clean, before putting it all back together. Oh, I almost forgot about the pinion gear on the motor. This is really easy, simply undo the retaining grub screw, and the old gear will slide off. Again, guess who forgot to take a photo before he took it off…This is a picture of the old one… And now the old spur gear…pretty f**cked eh? Putting it all back together. Now, this really is as simple as taking it apart, just in reverse. Start by rebuilding the slipper clutch and spur gear. With the gearbox in hand, place one of the metal slipper discs onto the gearbox shaft. This will only go on one way as the shaft has two flat surfaces to it. Take one of the slipper pads (the octagonal plastic bit,) and place it inside the spur gear, on the side facing the metal plate. Now carefully marry the two up. This can be a bit of a faff given that the slipper pad has a tendency to fall out of the spur gear. If you’ve managed to do this without losing the plot, repeat the process for the topside. Remember, plastic slipper pad first, then the metal disc. Once you have sandwiched them all back together, it’s time to pop the nyloc nut and spring back on. Don’t over tighten this, as you will need to adjust this later on, but that will be to your own personal preference. So, you should now have something that looks like this… Now that we have rebuilt the slipper clutch, it’s time to whack the motor mount plate back on. This will only go one way, so you can’t really get this wrong. Feel free to check the pictures further up if you get lost. Once you have done that, the next part will be down to personal preference. I chose to reattach the motor first, then popped the pinion gear on. But why I hear you ask? Simple. It allowed me to line the gears up before setting the gear mesh. That way, when I tighten everything back up, the gears should line up nicely and save having to slide the pinion gear back and fore. Once you are happy with the alignment, you will then need to set the gear mesh. For this I recommend you either watch a video on Youtube, or do it one of the many ways available. Oh, and don’t forget to put the dust cover back on the front of the gearbox when you’ve done that. There is no right or wrong way to set your gear mesh, just what is right for you. At this point I will say, that I cannot and will not be held accountable for any damage you may cause while doing this if you get it wrong. That’s on you, hence why I said look it up. With everything now in place, and your gear mesh set to your liking, it’s time to put everything back together on the car. Finishing up That’s pretty much it. Now all you have to do is put it all back together and test it. Simply follow the steps in reverse, and you’ll be good to go. If you’re not to great at things like this, take pictures of each step, or label things up, maybe even write down the sequence as you’re doing it. Well, I hope that wasn’t to boring for you and was simple enough to follow. If you’ve enjoyed this, please let me know, and I will likely try to do more of them in future. Thank you! Post Views: 39 Upgrades & Repairs