schuh007

Ive got an RC18T with mamba setup, but when I accelerate or try to go through grass I get a nasty noise, I have a new pinion and spur. Could it be the rear diff?

*Nitstklr72*

thats my guess

Seek and Destroy

it could be that the diffs need a rebuild or the gears are stripped on the diff and the bevel. i would suggest doing both.

hands without shadows

It could just be the new pinion and spur, are you sure they are the same pitch?? They need like half a run to "get used to each other" , you could try adding some light grease to them.

schuh007

ok, thanks, I think its the bevel, but Ill rebuild front and rear diffs. Also I noticed my rear right wheel was a little wobbly, is it the hub or maybe the A arm>?

tmaxx_23

im havin the same probablem but its all the time what would it be?

Seek and Destroy

can you give me a better description of how it happens and stuff, and what it sounds like?

tmaxx_23

it sounds like gears grinding and stripping. but it will get up 2 speed normal. i was thinkin it was the rear diff? email me at [email protected]

Seek and Destroy

it could be either diff. if you haven't already tear it apart down to the diffs and look at the gears on the diff and the bevel gear(little gear on the shaft) and see if they are sharp and pointy on everysingle tooth, if even a couple are dull or stripped then that could be the problem, also i would suggest that you rebuild the diffs. both of those were the problem on mine a long time ago. i would suggest you do both.

tmaxx_23

ok thanks ill try that

slogan

i've a 1/10 scale speedy cobra,xtm 4wd.grinding noise when triggered goes to top speed and every thing,but the grinding noise is my problem.please take it slow in explaining the reason,i'm new to rc world ,but in with it.money is not a problem.life is short and sometime fusstrating but rc makes the trip alot smoother.

Team Tekin

It's the gear mesh in the bevels.

I just replied to this same thing in another thread, so I'll just copy it here:

It sounds like your front diff is out of alignment with the input gear coming off the center driveshaft. (the bevels) These have to be "meshed" just like motor pinion to spur gears do. I'm almost positive that you need to get a set of 18T diff shims, like $3 from your local hobby shop and shim the front diff to tighten up the gear mesh, just a little bit. Too much will result in binding and a nasty squealing sound. Try the shims, I bet it fixes your problem, I've had to do it in 3 of my 18t's.

Rebuilding them while you're in there is a good idea, but it's the mesh being off that causes the grinding.

Good luck!

slogan

speedy cobra, everything was replaced from the chassis,bearing, gears, diffs,servo and saver alloy long arms etc.problem is this,that grinding noise is still there.i bought shims three different sizes .top speed is good (27t fantom motor and p2k pro 27t.)but when slowing the grinding noise is very noticeable.some pics below,i'm i doing something wrong or this truck is trash.money spent on this little upgrade maybe i should have bought a new truck.thanks

slogan

my sub-c battery packs got very hot,how to test the cells to know if the cells are good,plus the cells have no labels how to test to know the mah.the heat shink was destroyed.some cells was tenergy 3800 and some was 3000 team orion.any help please thanks