Tmaxx revs up but won't move

[Theophilus48]

So I've got a tmaxx 2.5 with two speed with reverse, while everything sounds good with the engine (it revs up and idles nicely) it won't move the car. I checked the wheels and axles, put new clutch nobs in it, tightened the clutch completely than loosened it 1/4 of a turn, the gear on the crankshaft is in mesh with the one that has the clutch with the spring on it, It goes properly in gear and if I hold it in hand the wheels start turning but they don't have enough power to move the car, please tell me what I can do, or what the problem might be...thanx !!

 

[Rolex]

Check the pins in the drive shaft. If one has snapped, it will still have enough friction to turn the wheels off the ground but will just spin under load.
Also check if the shaft coming OUT of the trans is turning when it's under load.

 

[Nitrotrout]

^ That's a good place to look first. Hopefully it's not the small pin inside the transmission.

 

[Theophilus48]

thanx guys for the fast response...i'll check that out tomorrow, could you show me a photo with those pins and their location or explain more, please?

 

[Antonio G]

The reverse in the transmission screws up the transmission, mine because of the reverse screwed up the shifting in my truck wouldn't shift into 1st or 2nd, so be advised.

 

[olds97_lss]

If the input shaft of the trans is spinning and the output shaft isn't, try and see if your forward/reverse servo is working properly and attempt to shift it while it's idling to see if it works and then drives in one direction or the other.

If it doesn't and if you don't "need to have" reverse, get a forward only kit and tear into the trans. The FOC removes a lot of crap out of the trans usually and makes for a more solid transmission.

 

[Theophilus48]

The screw on the main shaft, that holds the gears together was broken...changed that and works now problem solved!!

 

[Brandonc327]

Mine does odd stuff too. sometimes it revs way way up then boom like someone dumped the clutch. reverse has only worked 3 times out of box. Not very happy kinda a piece of junk truck

 

[Antonio G]

Ya,mine I cleaned out the transmission thoroughly made sure that nothing was broken. Still does not shift, just put a forward only kit in it, hoping to get it to shift.

 

[olds97_lss]

Try holding it off the ground and slowly increasing the throttle to see if it shifts. Since the previous owner may not have known how to take care of it, the shift point could be out of wack. Also, if the slipper is slipping too much or the clutch shoes are worn/dirty/slipping, it won't shift (or sound like it shifts). Could also just be the engine tune isn't getting enough RPM's to shift.

 

[cbaker65]

So I've got a tmaxx 2.5 with two speed with reverse, while everything sounds good with the engine (it revs up and idles nicely) it won't move the car. I checked the wheels and axles, put new clutch nobs in it, tightened the clutch completely than loosened it 1/4 of a turn, the gear on the crankshaft is in mesh with the one that has the clutch with the spring on it, It goes properly in gear and if I hold it in hand the wheels start turning but they don't have enough power to move the car, please tell me what I can do, or what the problem might be...thanx !!

It maybe the one-way bearing inside the transmission!
I don't have a T-maxx,but I have an Mgt. I also run a greasless trans because any
type of grease or lube gets on the o-way bearing will cause it to slip & fry.

 

[olds97_lss]

That's a good point. Forgot the original owner sounded like he put oil in the trans case. However, if the OWB was slipping, then it wouldn't take off in first gear as that's what locks when your in first, then releases when 2nd gear takes over. If it was seized though, that may cause it not to shift.

 

[Theophilus48]

For those disappointed in the tmaxx and even other rc trucks, you shouldn't be, that's what makes this world nicer, having to repair/ set stuff up, you might be better of with a broken truck than with a good one, cause repairing these things is gonna lead to a better understanding of they're functionality.
Now if your engine is revving high and the truck is moving right for 1st gear than your problem could be the transmissions shift point screw, the one that you can acces without taking anything apart.
If your truck is idling right, than you rev it up and it stalls you should set your high speed needle, your engine is running lean, that means that at higher revs it will get more air than needed and less gas, you might also damage the engine.