Traxxas 2.5 bucking at idle

[AllanQ]

Heres a link I found to mod the transmission to stop the bucking. Hope this helps.
http://monster.traxxas.com/showthread.php?t=268460&highlight=no+buck+mod

 

[drummerguy101]

ooooooooo t maxx 0000000

woud be great if ya removed the reverse i think? .great post :resp:

 

[Tom H.]

woud be great if ya removed the reverse i think? .great post :resp:

Yeah, but reverse is kinda handy to have sometimes.

 

[f1n3sse]

I have a few traxxas models the no buck fix is quick and easy. the only problem is that with the 2.5 motors not having that much power, it is a traxxas model, your low end throttle response will get worse. the reason they buck is because there is a pawl in the tranny that engages at a certain rpm similar to the pawl that grabs second gear its a flaw in the transmission design so you will actuall put an output yoke screw to keep the tranny engaged in first gear to bypass the pawl that is supposed to do it. not giving the weak 2.5 motor time to wind up and grab 1st you can only imagine the loss in low end power and tourqe your going to encounter. my suggestion, sell your traxxas and buy a savage

The reverse has absolutely nothing to do with the bucking.

 

[AllanQ]

I just finished the tranny mod and here is what I found. It was super easy to do. I did the original mod because I did not feel like cutting the pins out of the F/R clutch bell. This one has the most risk, but I am willing to take it. The only other little quirk was when I shift to reverse the truck goes forward just a little until the reverse gear engages, same thing happens when shifting forward. There was no loss of low end response that I noticed, if anything the response was a little quicker since the fwd or reverse gear are always engaged.

 

[f1n3sse]

glad to hear it all worked out for you. Its hard to believe you didn't lose any low end but you know your truck and I'm not gonna argue with you. 1 thing you might want to consider now is every 2 months or so check up on your mod, the torque from your motor will tend to bend the yoke screw you put in slightly and will eventually break. just keep checking on it periodically to make sure nothing comes loose inside your tranny

 

[AllanQ]

f1n3sse. thanks for the tip. i was thinking about the yoke screws or the gear itself possibly breaking. I can see where it could snap pretty easy. Have you heard of this happening to anyone? Also, I hope the pins would break before the tranny gears if it got shifted to reverse by accident, but I really do not want to test that theory out.

 

[f1n3sse]

the gear wont break because it is a steel gear that the yoke pin goes into. the yoke pin itself will only get weaker over time and if you take your tranny apart in 2 months you will see that the pin will be slightly bent from the torque of the motor. just keep an eye on it. I never had my truck accidentally go into reverse.