INJORA 12T/22T Overdrive Gear and 24T/10T Underdrive Alloy Steel Helical Gear Set for TRX4M 1/18 RC Crawler Car Upgrade

Rear underdrive gears went in fine with minimal gear noise and spins freely. Front overdrive was terrible. Ring gear was out of round and no amount of adjustment could get rid of the clicking and binding. Had to put the stock gears back in because I couldn’t get it drivable with these.EDIT: customer service sent me a new front ring and pinion and it’s on point! I have over/underdrive gears from Injora in my 1/10 crawlers and they were all great. This was the first time I’ve had an issue and it got resolved quickly.

They fit in the injora axles to?? The diffs came pretty much perfect, 1 shim on the inside and one in front of the drive shaft.No play in the driveshafts either.10/10

Fit perfectly and did what they are supposed to do. Noticed a difference right away when crawling.

These have worked well in my TRX-4m Injora Tarantula build. Gives a lot of gripping feel.Note: These are good for a slow speed crawler. Do not use them if you are mainly faster trail driving as this will wear your tires faster.

Mine came with 2 shims per set of gears and no matter what i do the front skips ive added shims and all it does is get tight but still has a skip to it. So I tried a different brand and it works fine so its definitely something in the injora 12/24 set that i got i reached out now they want videos of the installation process this will be he 3rd time ive had it apart so im just returning them its obviously their product cause the other brand i got are fine in it with 1 shim get the meus ones they seemed to work better the gears seem like it was cut poorly to me. I have been in the rc hobby since the early 80s and this is the first time ive ever had a issue with a diff gear fitting right just a horrible experience and waste of time and money

The only thing i have to complain but i dont really mind it much is that at full turn they do bind up a bit (actually its just the front gears) not sure what the case may be i checked everything used the shimes and i got it to where im happy but just keep in mind they will bind just a hair some way or another but it’s hardly noticeable

One gear set out of round ring gear. Binding and unable to rotate drivetrain :(Update they replaced them and theyre a bit better but not perfect. Thanks

The media could not be loaded. Amazing quality, feels and looks strong, improves climbing and turning. The gears have to be set up almost perfectly for them to work correctly and not bind, I’ll provide a video on how you could use the shims that come with the gears. The price is okay a little expensive for what it is but if it works it works.