A Lovely Crunching Noise

[Razorsmile]

If any of you guys know me I'm a noob at this nitro thing but it seems i have a problem.

I'm running almost a stock savage 21, except I've just installed dual discs.and a tsais chromed pipe.

Things are ok but , when you push the truck manually , theres a nice Crunching slipping sound , I have an excellent mesh between the gears and motor cogs,

But it does sound like the gears are slipping something rotten , it doesn't affect the running of the car, it seems to run fine.
I'm not sure if the 2nd gear kicks in all the time?
kinda hard to tell.

Someone in the local club to me mentioned i should swap the standard cell batteries for a humpback as this may affect the power transferred to the servos and this might help I'm in the process of charging the pack now.
But i thought i might post incase you guys have any other ideas.
Again thanks for help

 

[beason]

sounds like a diff.. grab on front tire and try to turn the other.. then do the same with the rear if ether slips or pops and lets you spin then that diff is bad..

 

[Candyman]

Crunching sounds are never good. But the hard part is figuring where they're coming from. 1 typical culprit is the differentials. Usually you do what beason said. Hold one tire and turn the opposite and see if there's any noise. Also, check the tranny. There have been a few issues with the screws that hold the ring on the 2-speed gears. Mine was starting to eat away at the tranny case last time I tore it down. I had to grind it a bit to get a smooth seat. And if you just installed the dual discs, make sure the pads aren't binding.

 

[Razorsmile]

Ok tired holding the tyres and thats fine ,you can put a hell of a force on the wheels, and theres no slippage at all

i was considering buying the 3 speed gears are they recommended seems what i have ready they add the extra 10% torque etc ? yea or nea?

 

[olds97_lss]

How much fuel has been run through the drivetrain?

My dual disk clutch made a grinding/chinging sound when it got worn. The hex in the middle of the disks was deformed and was making the disks stick on the hex shaft. As they spun, they would bind, let go, bind, let go... I finally just took it off and went back to stock with a high torque throttle brake servo instead.

Also, diff cups get grindy as well. Especially the center ones mounted to the trans. Look for notches where the dog ears rub. As the cup wears, the dog ears get stuck, then let go as the shaft turns. Makes a terrible racket and give it a very lurchy feel as you roll it.

 

[arawak420]

mine makes that sound as well. it always did since the day i put it together. its the metal brake disc touching.

 

[BADNBADN]

My dual disk brakes rub, the one closest to the motor. I just ran the truck until it wore itself down.

 

[Nevaren]

i get the crunch sound too from the dual disc set up... it gets quieter as they run in.