rc18t questions

[gtoris]

My fiancee and I just picked up a couple rc18t's. We were out having fun with them when all of the sudden her 18t started making this horrible whinning sound, and she said there was a loss of power. I tore it apart thinking that it was the rear diff, but it feels the same as the front. I don't really know anything about diffs though, so I am not sure! Any thoughts or ideas would be greatly appreciated.

[___rollin___]

thats wierd, I would think that a "new" 18t would have shimmed diffs. Maybe not. But I would say, rebuild the diff, but get Associated diff shims, they are like 99 cents. But after that you shouldnt have any problems.

[gtoris]

the diffs do have shims in them. but looking at it closer her spur gear is a little tore up but not stripped by any means. could that be causeing the problem?

[dudidood]

Bring it to the nearest Hobby shop, or you could search in your manual for some clues.
Good luck.

[baih]

a common problem with the 18t is pebbles can get stuck between the spur gear and lower spur gear cover. can you take a picture of the spur gear and post it.

[horndog732000]

I've had my son's 18T apart as far as it can go and back like 5 times and this is what I've found in a nutshell: The diffs used to slip a lot causing a "clicking" sound. This happened a LOT before I put the shims in, but the gears were all still good, so I'd be surprised if you stripped one of those. And besides, you said you already checked them. There's only a couple other things it could be. The next point to look at would be the spur gear, do the teeth on the outside look okay? What about the inside where it drives the shaft? I also found the motor mounts on mine to be loose causing too much of a gap between the spur gear and the pinion (motor) gear. AND even with the motor mounts tight you can actually twist the chassis (front to back) causing that gap to change. (It flexes back pretty well though so I'm sure that's not your problem.) Also if the set screw in the pinion gear comes loose enough the motor shaft can spin inside the gear so check that. Overall, a whining sound usually comes from a flat spot or stripped teeth on a gear. Also if you haven't already, you could set the truck in front of you and while holding it hit the throttle. That might make it easier to pin point the problem. Hope this helps.

[gtoris]

I did figure out the problem, it was the spur gear, must have been a stone in there, cause everything else was tight. just want to thank everybody for there posts, and ideas.