who thinks they know what this wierd sound is?
 

this is on a 3905 emaxx. it mades a wierd noise everytime i accelerate. the noise sounds like a old door or floor creaking or like something stretching, or dead leaves being stepped on. odd thing is, it only makes the sound:
- when you go forward. reverse doesnt make sound
- when i lift up the truck and accelerate, no sound
- when i lift up my truck and compress my springs to mimic as though the truck is on the ground, no sound
- when i roll the truck forward with my hands when its on the ground, it doesnt make that noise either.
you only hear the sound in the beginning of the acceleration, as soon as the truck goes , the sound stops
its not a grinding noise so i doubt its the gears from the diffs or gearbox.
and the sound is coming from the rear of the truck positively.

heres a a sound bit no video sorry:
http://home.earthlink.net/~webhost/traxxas/emaxx.mp3
picture what i was doing with the emaxx...mic stand holding a nice 3/4" diaphragm condenser about 1' off the floor, down slightly from horizontal. emaxx backs up to the mic and i jerk the trigger and repeat

I think it's a combination of drivetrain slop and the slipper slipping.

yep jason's got it, sounds like the slipper.. or maybe a bad bearing that rattles when its under load

Ive heard numerous complaints like this from the new e-maxx... Theirs a vid on youtube somewere about one of them.

my slipper is like one full turn from being the tightest already. its still a fairly new truck. it didnt do this untill like a week ago. i cleaned out the bearings on the out and inside of every wheel. very funny thing is also if its a bad slipper would it do this:
i place my truck on my lap. the front of the truck is facing away from me. i squeeze the left and right front tires with my thighs so that both front wheels dont move. then i turn both the back left and back right tires with both my hands in the same direction, this is when itll make that noise...creaky noise or whatever the sound.
i turn my truck around and do the same thing and turn the front two wheels this time, and same thing, i hear the noise in the rear.

gear noise from the center diff? is the center diff limited slip?

the noise is coming from the rear. maybe the rear diffs. but anohter person from another forum has the exact same problem and he opened and checked his diffs. everything was fine in there.

Did you try tightening your slipper up to the tightest it can go? Then see if the noise is still there. JMO.

I have had a bad sounding diff that looked fine, but I replaced it with a new one and no more problem. The plastic diff cup could be stretched or stressed enough to let the gears slip.

I would guess it's a bad diff. Thats why it only makes the noise under load and in reverse the load is on the front diff.

i think you guys are right about the diff. thats where i think i hear where the sound is coming from. but how did my diff already blow after one month? i dont even have brushless yet. is it because i have my slipper too tight? i love doing wheelies thats why i have it so tight. but someone told me you can have it very tight even like 1/4 turn to the tightest and itll be ok. and im sure you guys with brushless setups have waaay more torque than i do and can do wheelies at will and prolly have no diff probs.
so how did it cause this so i know how to fix it? and lastly, what if i dont fix the problem, can it ruin more things later? because my truck still runs perfectly fine other than just hearing that sound. should i just wait till it blows then replace it, just incase its not even the diffs?
oh hey i made this post in other forums, feel free to check what they said maybe that would help out. sorry, this noise is buggin the ish outta me..need all the brains i can get.
http://www.rcuniverse.com/forum/m_74...tm.htm#7442599
http://radiocontrolzone.com/showthread.php?t=248060
http://monster.traxxas.com/showthread.php?t=416312

It kinda sounds like they forgot to put grease in the tranny at the factory.:lol:

ok, im almost sure i know what the prob is. one of the guys that had the same problem replaced his rear bulks and the noise is now gone! reason for replacing was because the screws from the skid plate going onto the bulkhead was stripped.
and last night while examining my truck again, i titened all the screws on the rear of the truck and i did notice that i had one screw stripped exactly where the skidplate goes onto the bulkhead. i tried many screws but still wouldnt get tight. i really hope that this was the problem.
hey guys, is it bad if i didnt replace that bulkhead? its only one screw should i wait till it gets worse..whats the worst that can happen. i sorta dont feel like changing it just yet since i think its just a stripped screw.

thanks

put a couple drops of superglue in the hole and put the screw in.

ive heard of ppl using epoxy, is that the same thing as superglue?

Check your driveshafts; they tend to bind against the shocks because they are too fat. check to see if you can see if they are damaged: scratched all around is what they usually do.

About the bulk; you can drill the hole a bit deeper (or through) with an 2.5 mm drill, and put a longer screw in it.

yea for sure its not the driveshaft rubbing on the shocks. i dunno bout the drilling the hole, i think that would make the bulk very weak. i think using the super glue would be better.

When you turn the wheels how far can you turn them? Does it just make that sound and keep turning, or do the wheels lock up once you've taken the slack out of the drive train? With e-maxx transmissions if the front wheels can spin at different speeds to the rear wheels then somethings not right.
If you can turn the rear wheels while holding the front wheels which drive shafts turn? Do the motors turn when one set of wheels turn?
If the rear center shaft doesn't turn when the rear wheels are, then it is in the rear of the car and probably the diff.

no actually nothing spins...everything locks up, but im still able to hear that stretching noise. but it sounds like it has to stretch cus im like trying to force it to spin but its not letting me. by the way, im not like really forcing it to spin, or that will just ruin my diffs. im just giving it the tension and thats when i hear that streching noise.
and now im skeptical bout using that glue because what if one day my bulks do break , will i have problem removing that screw?

Twist in the driveshafts? Diff case moving in the bulks? I'm not really sure, I haven't heard noises like that in my cars.

nope its none of those. i ll wait till something breaks so i know exactly what to fix then haha. for now, i may jus do the ca glue in the thread and screw it in

It will still come out when you want it too. The glue won't stick to the screw that bad. You can normally just unscrew it. Are you sure the diff doesn't move in the bulkheads? Try a drop or 2 of water where the diff fits in the bulk heads then see if the sound is gone.