INJORA Overdrive Underdrive Stainless Steel Transmission Gear Set for 1/18 TRX4M

I put the OD gearset in a stock transmission along with a bearing kit, and it works great! Gears are quiet, and the speed increase is noticeable. Added the brushless motor later, and its a full on speed demon! Very happy with the gearset.

One of first upgrades! Great quality!!

Easy to replace and a perfect option to Slow down the cars for my kids. Climbing is much easier. Required when wheel size was also increased.

Just right gear for your 180/48t motor for 1:18 crawlers, third gearset and all are equally quiet, comparable to original plastic gearing, not too fast and neither slow, with nice slow motion handling

Veuillez bien repérer l'ordre de montage avant de changer les engrenages. L'assemblage et très aisé et change littéralement le comportement de votre machine ! Je possède 2 jeux, le sous multiplié offre beaucoup de couple et de souplesse. Le plus 71% vous permet de transformer votre engin en bombe rapide pour le fun. Je conseille les roulements à billes et le Carter de boîte en métal.

These under drive gears are amazing, the quality and precision engineering is absolutely fantastic! Remember to get yourself a bearing set so that you can swap out the transmission bushes for bearings whilst you have it stripped, and it would also be worth getting the steel drive shafts, the original plastic ones both sheared after 2 days!

I really needed these after stripping the plastic ones twice. Bought the underdrive ratio and love it. Still plenty of speed to launch over stuff. (Brushless mini komodo) I installed into an aluminum housing. Tested at Bragg Creek.

In my opinion the quality is just as good as what they look like on the picture been using them for a couple of weeks now and they are performing really well.
Great product for the price

Absolutely perfect together with the Roverin M30 G2 FOC Motor and ESC

After upgrading to a very fast brushless motor, this 40:1 gear reduction brings the crawl speeds to the best possible ratio while still retailing similar top speeds as the original motor. However, all that torque will require you to reinforce the rest of the running gear.

arrived in a timely manner good quality and fit, works very well

Ok

Been running these gears for quite awhile now, figured leave a review. Cons: right off the top, noisy even with thick EP grease. I am running the low gear set/transmission in an A18 with 3Flow9 door sliders and now that is ludicrous loud. With that said if noise is concerning sell the truck and take up knitting. That’s it for cons.
Pros: many much more torque, like a dead a cat moves faster. Paired with a good brushed ESC, including the MB100 sold here is pristine. The stock 2.5 ECM supplied by Traxxas is good for brake lights and that’s about it, I could use another word but might upon frowned upon. Far as motor the 48T purple motor from Injora is solid, logged god only knows how many hours on rocks and trails on 48T’s. 48T has some snap and some usable high end rotation due to low turn count. Holmes 66T is another solid option as well. With either motor my recommendation is to up fit a better ESC besides the lack luster blue brick. Best option is just get the whole boat, Injora motor/aluminum case/48T motor. Open it, grease it, send it. Haven't had any issue marrying gears alone into stock transmission housing so either way works. The entire package is around 75ish grams IIRC, I know the internet and inflooooencers say “low COG” and truck must weigh -275 grams so the weight might be buzz kill.

The pinion doesn't fit well on the motor axle. It's very hard to put it in place, with the risk to damage the rotor.
Once installed, the new gears are quite noisy vs the stock astic parts. Performance are ok

Suit the stock plastic housing and works well.

Running 74mm tires on my buggy with the 180 purple motor, went from 40.3:1 to 9.7:1. Much, MUCH faster. High-speed fun!

Best gears

Contacted the staff prior to purchasing due to a few reviews citing fitment issues inside the aluminum housing. I have had zero issues with the crawler gears in multiple transmissions - this was the first time getting the 71% overdrive gearing. I no longer have a stock plastic transmission to test on, but it does bind if fully tightened inside the injora aluminum transmission which is disappointing. They seem to work otherwise, but won't be able to fully tighten my transmission closed.

Direct and perfect fit on the stock transmission. Works great, pretty quiet. I tried fitting these in the injora tall transmission, but it had fitment issues, while the traxxas overdrive gear fit perfectly. So be careful if you use another transmission than the stock one, it's not a guaranteed fit

Excellent quality

Super great fit used a little grease and they work great I've put my rig in some serious binds and have not stripped a set yet!

These slow the vehicle down and make it easiest to control for climbing.

A++ quality

Well done Injora! It brings great performance!

Beautiful and really well done

These crawl gears make the TRX4m much easier to handle on slopes.