XRAY - Model racing cars

Hello Guys,

In France, a lot of NT1 know this problem with the second gear. Never when the cars are new, but after some running time. So we think this problem comes from a part which wears out.

We try all the solutions that you suggested in this forum with some friends drivers : to change engine, to dremel the engine holes, clutch, axle, one way, perfect gear play, small theeth difference, ..... even to change chassis and put 4 mm one. All, we try all.

After all these experiences, we think the problem comes from the gear box itself. The first good solution we found was to decrease the SHOE GAP by tighten the setscrews. We noticed this solution gives a smoother transition between the first and second speed. This solution can work but we think this is not the real solution. With the following explanation (below), you are going to understand why this first solution can work indirectly.

Today, we think the problem comes from the setscrews themselves. After some running time, the end of the setscrews are damaged and they eventually jammed on the cylinder. Then, with regard to the adapter, the shoes can not work perfectly and it cause blockings of the gear-box. This box jams then by intermittence and it forces a lot on the second gear, broken it in some minutes.

This last Sunday, on two cars with this problem of broken second gear in some minutes, we removed the setscrews, we file down the end of these screws (to be flat) and we remounted them in the shoes. Then, we run more than 20 minutes without problem and the appearance of the second gear was perfect. (it’s why we think the first solution works, but not because the smoothest transition but because the setscrews are moved).

At now, it’s the best explanation we have and the best solutions we found.
I sent an e.mail to Martin and Mario with this explanation. May be they can give us their opinion on this suggestion through this forum.

Hope it can help.

See you, guys.

always check you travel on your servo i had to much movment on the throttle servo and on full throttle would pull on the carby and move the engine a fraction ..
it not much but enough to pull the mesh appart and strip 2nd gear happened to me ..
7 gears late found my problem was i had to muck end travel on my servo's.
wearth checking also i find 53 2nd gear to be softer than the others
and i think the heat sofins the plastic then you hit seconed and there goes 2nd

hello Grub,

This is a good remark but it's just because you have too much movment at your servo. Other drivers (very good level French drivers) and myself, we have the good movment at the servo and we have broken the second gear. I think we are not in front of the same problem.

Anyway, this is good remark. I suppose in your case, as it's a distance problem between transmission, the first gear is also damaged, even if not broken.

See you, man.

gidday JoseNT1
what gear split you running i had a 6 tooth split and i had major 2nd gear striping
i was running 16/23 53/60.
also make sure the second gear changes smoothly as mine you'se to jump into second and again bye bye 2 nd gear

Hello Australian friend,

I run very often 16/22 or 17/23 with 54/60. I like to run with the same difference theet at clutch and at the box. But frankly speaking, I think it's not very important.
We honestly think the problem comes from the gear box itself.
Please, change only the 2 setscrews of your gear box (the 2 setscrews and the 2 cylinders would be perfect) and adjust your gear box as it's written in the Set Up book. Normally, you will have no more problem during some time.
After some races, the setscrews will be damaged gradually and it will be jam the box (if jam = bye bye second gear). To delay this event (blockage of the second gear-box), you can turn slightly the setscrews periodically.

Try this solution, my friend. This explanation is the best we found and seems to be logical. It works in France, no reason this solution does not work in Australia ... and everywhere.

Good luck for your tests.

See you, man.