kingjbh

I recently bought a 2speed transmission for my HPI Super Nitro.

On the first run, the tranny shifted four times before the car stoped at which time i noticed the second gear was totally stripped.

I bought a new second gear, installed it, and ran the car again. This time the car ran for about 10 minutes before the second gear totally stripped, and the first gear had chunks missing from it.

Any idea what is going on? Any tips for how I can prevent this from happeneing??

TheRagunCajun

Your problem is your gear mesh isnt correct. Gear mesh is how close/far apart your teeth are together. Im guessing your not using the stock engine in you rs4 cuz it should mesh properly. Reason is, on the stock engine, the engine has mounts built into it. So it sets mesh for you when you install it. I've heard numerous times on ways to set your mesh right and they always say the same thing. They say to put a peice of paper b/w the clutchbell and spur gears and press together. I found this way is descent if your sh*t up a creeck without a paddle. On my nrs4 2, i set my mesh by sight. I do that because the paper method is to far off and it messes up my teeth on my clutchbell. Besides, it never turns out he same. Since you dont know anything about how your mesh is suppose to look, use the paper method. When you get the hang of it, ditch the paper and set it by site so you can have better performance. BTW make sure you installed you 2-speed in correct . I hope you got the heavy duty 2-speed, cuz the other one isnt worth the $$$.

saints1115

If the two speed is similar to the ones we run in 1/8,check the one way bearing in the first gear assembly. If it does`nt roll freely when the two speed shifts the first set will still be driven as the second set locks up causing all four gears to have power applied at the same time. Since each gearset cannot turn at the same rpm due to the different ratios,the second set will almost always be the one to get mulched. Clean the oneway bearing completely and reoil or replace altogether. This is always the first thing we check if we lose a second gear.

popsracer

kingjbh;

It sounds like the mesh is off. Minimum space between the gears without binding is what you need. In all the Years that I've owned HPI's, I think I've only had to replace 2 gears, one from pebble damage and the other from a broken 2spd shaft.

If the One-Way is bad, the car will not run at all. The tranny will just slip. Put a small dab of grease on the inside of the One-Way bearing every couple of weeks/races.

V-One S

It can also happen if the chassis is slightly bent, but you cant see it

sparksy

iTrader: (14)

I had a similar thing happen on my drag rs4racer2.... I hade a MT12 in there and not running the belt tensioner/brace. The torque of the engine pulls the clutch bell away from the 2 speed.... Admittedly I had cut a hell of a lot out of the chassis, and there wasnt much left.