Scx10 Problems

[Trentenowns]

So i have had this rig for about 2 months. I drove it for about 2 weeks and had a friggin blast with it! then i stripped my spur gear, upon replacing that i was tightening my pinion and stripped the screw..Couldn't get it off the motor.
so i went ahead and bought a 35t Holmes motor and changed my pinion to a 15t. Then put it all together and now it lunges..hard to explain but ill post a vid.

[Trentenowns]

Heres the videohttp://www.youtube.com/watch?v=ddfeWElVTqM

[mjc597]

How are your driveshaft angles? I can't see them in the video but if they are real severe angles it will cause that..can you shoot a pic of them? I know you didn't say anything about changing the links or anything, but you never know..

[Trentenowns]

[Trentenowns]

[Trentenowns]

[mark32]

gear mesh is to tight set it up with a piece of paper

[Meatwad]

Mesh should be enough that you have a slight tick of backlash. Hold the pinion with a finger and rotate the spur back and forth, should be slight play.

If thats good then try disconnecting the driveshafts from the transmission. Watch the transmission outputs while applying throttle, check to see if you can still see the lunging. If so, then it's either the pinion/spur or somewhere in the tranny. If not, then it's further down the motion signal chain... either the driveshafts or the axles somewhere.

[Rorro]

shafts out of phase.

[RyanRay]

make some DIY links too from brakeline allthread and revo rod ends. those plastic links flex in and with the torque that nice motor has i'm certan they are letting your diffs wrap and bind. while a honcho rtr is great out the box you should almost put some metal lower links on first thing. might be why you hurt the spur to start. The plastic will flex when your hit the throttle hard or hit something head on but the motor will keep turning and the tires dig in and the rear end will start to wrap and bend the links in and move the hole diff forwar and wreck the drive line. I know this because I learned it the hard way. the plastic links have to go. start with the lower at the very least and replace them when you can

[TacoCrawler]

the link was dead...

but a clue from another user regarding "lunging"
tells me the drive shafts are not in phase.
There is a tiny alignment mark on each end of each drive shaft.
If those are off by any spline count... it will lunge
and the suspension will shake if they're way out of phase.

If you can't find the alignment marks or they were possibly ground off...
Look at the pins in the cups and align the DS's using those.
Both ends require those pins to be in alignment with each other.

Don't overtighten the spur/pinion gear mesh.
Friction heat could melt that spur gear...
and that could soften the teeth on it and cause it to fail.
Metal spur gears are available... and somewhat pricey...
But you shouldn't need that unless you have tons of power spinning things.
The plastic gear will less likely fail if the mesh is set correctly.

Like stated above...
there should be a slight backlash between the teeth.
Too loose would be bad too.

to save yer old motor...
just drill out the old grub screw.

If trying to save the pinion gear as well...
you may be able to use a larger size allen wrench or possibly an EZ out.

[HPI-Killer]

^^Taco is right with drilling your grub BUT make sure you drill it straight on or you could drill into the pinion intself instead and eliminate any chance of getting the grub out.^^

Honestly, I dont use slipper clutches just for the fact I ran them 100% tight anyways and would get livid pissed when I would adjust the nut to what I think is plenty tight then put it all back together and go hit the trail and not be able to bind up even a little, so I said screw slippers...