T-MAXX geerbox problem

[CRASH]

hi Guys

my bro just brought a hopped up .21 t-maxx and it will not drive
forward it drives backwards fine, but when you select forward and give it some gas it just revs.


it is definately an internal geerbox problem and I've had the box
apart several times and found a couple of problems and fixed them but still it has no forward drive.


anyone got any idea where the problem might lay as i'm stumped by it.

 

[dougc]

Some times it just does that... It is a small point from when it is in gear and out of gear. Try new batterys if it is a good control try end poin adjustments... also will it go foward over time?

 

[CRASH]

hi doug
i dont think you get me the box will NOT select forward drive
at all regardelss of how long you wait and make sure the revs are low etc, this is why i said it is an internal geerbox problem.

the box is some blur anodiesed alloy one, i just swapped it out for a standard t-maxx one and thats perfect.

i'd still like to get the alloy one working though.

 

[Candyman]

So what you're saying is that with the standard plastic case, the tranny shifts fine, but with the aluminun case it won't go forward? If that's the case, I'd imagine there's something in the design of the case that's prohibiting the proper amount of throw of the shifting fork. It has to travel a sufficient distance to engage the gears. And if just changing the case creates that trouble, I suspect the case.

 

[CRASH]

hi Candyman


i guess i didnt explain it too well sorry i'll try again



me bros tmaxx has a super hopped up anodised alloy geerbox
and when we try and drive the car it will go backwards fine but it wont go forwards, i have stripped this alloy geerbox a few times now and i still can't get it to drive forwards.

i replaced the complete alloy geerbox for a spare orig tmaxx plastic one and now the car moves fine in both directions.


but i would still like to get the alloy geerbox working right, it is an internal fault and i can't see anything untoward in it but then again i havent seen inside one before so not too sure i would notice a problem if i see it .

 

[SuperMaxx97]

it sounds like the aluminum one isint letting it switch right, it is getting stuck in nuetral. but, if the plastic one works then i would jsut leave that one in there for a while, meanwhile try and figure out what is wrong with the aluminum one.

could it be that soemthign is in the aluminum one that isnt supposed to be there??? take them both apart next time and look and see what the plastic one is like, then look at the aluminum one, they shoudl be the same

bryan

 

[wdavidhicks]

The shift fork moves a clutch bell back and forth between the forward and reverse output gears. Both of those output gears have a spring loaded pawl that has to engage the clutch bell through the miracle of centrifugal force. You might make sure that pawl in the forward output gear moves easily. (The pawl engaging the clutch is what gives the Maxx that shuddering at takeoff, by the way.)

Here's a good photo of a working tranny with reverse. The forward gear is on the bottom in that first photo. The reverse is on top.

https://www.rcnitrotalk.com/forum/showthread.php?s=&threadid=7030

How about the forward only conversion?? That'll fix your problem.

 

[Hypedonrc]

So I though this would be a good thread to ask about my problem. My Maxx recently started to have resistance when pushed around by hand. I have checked for static brake, and when suspended in the air all 4 tires spin freely when moved seperatly. Hold one (front or back) and spin the other (same front or back) it gets resistance. Any ideas? Is the tranny on the verge of going out?
:madface: 1 prob after another!