almunro

iTrader: (4)

I have bought a 2nd hand F18T that was in poor condition.

After rebuilding her im wondering about the diffs. They have the recommended 2mm locknut in them, but i cant seem to tighten them up to the specified torque. How do you guys hold the locknut and tighten the screw when the nut is down in the diff outdrive? None of my tools will fit in and so the nut just turns.

The motor that came with it (Xray 370 supersize) burnt out in a matter of minutes. It ran so hot i could smell it. After taking out the motor and testing the drivetrain, she doesnt seem to roll very freely when i push it along the ground. A good shove only sends her about 10" before she stops. The diffs are smooth, and everything seems fine with no binding, but my rc18t rolls farther even with the motor in it! Is there something i should be looking for? How freely do other peoples f18's roll without the motor?

Any advice would be appreciated.

Alex

almunro

iTrader: (4)

anyone?

burnineyes

iTrader: (17)

It may take a few days for the right person to see this thread since this is not a super popular truck. It may also help to put this in the official F18 thread. I dont have one of these so my advice would be very general.

I do have some cars that use a locknut in the diff, but they all have a slot the the nut will slide into to keep it from turning. I have also put a locknut on a diff that the bolt originally threaded into the plastic outdrive. For this I just stuck a small flat screwdriver in the outdrive and it will keep the nut from turning while I tighten it.

As far as rolling without the motor installed, I believe it should roll very easily. When I am not sure where to start, I will simply remove one diff at a time and put it back together to try again. Kind of a pain, but once you get to know the car better you will probably be able to spot where the problem is right away. Since you say the truck was in poor condition, I suspect maybe the previous owner had problems with diff gears and may have shimmed one or both too tight.

almunro

iTrader: (4)

Thanks for your replies on my two threads burnineyes.

I will take the shims out of the caster diffs and see how she goes. Ive tried the screwdriver down the outdrive but it doesnt seem to hold it enough. I will keep searching for a suitable tool to tighten it.

I'll get another pinion for the rc18t and see how the temps go. The truck came with Nimh so the lipos are probably the reason for the heat. Again i'll keep you posted.

cheers for your advice!

Alex

almunro

iTrader: (4)

Okay, so after rebuilding the drivetrain again, and everything seeming ok I found the problem. It wasnt the diffs as unshimmed the gears slipped badly. It was the simplest bit that i didnt look at. It was how tight the wheel nuts were tightened. To get the wheels to freewheel and spin for a decent amount of time, i needed to loosen the nuts a fair amount. To such an extent that the rims are slightly (1-2mm) wobbly.

This is not the case on my rc18t so seems a it unusual to me. Anyway it seems to drive alot better now.

Thanks!

burnineyes

iTrader: (17)

Oh wow, I have seen that before but I guess it seems so simple that I wouldnt expect it. Anyways, glad you got it sorted out. Be sure to let us know how you compare the two trucks once you have everything up and running.