Yesterday I replaced the factory stock (38 tooth) spur gear with a (36 tooth) gear. I stayed with the factory stock (14 tooth)clutch bell.I reinstalled the 3.3 onto my truck, and followed the gear meshing procedure as explained on Traxxas's "support" section on its website. I did not replace the slipper clutch shoes or the clutch plate as they have neither severe wear nor visible damage. I tightened down the clutch nut in 1/8 turn increments until the clutch engaged enough to make the truck move under throttle. I made sure to NOT overtighten the clutch.....The problem I am having is when I apply throttle 1/4-1/2 or more throttle, the engine RPMs are notably higher in relation to forward speed than before the replacement of the spur gear. I checked to see if I could move the engine closer to the spur gear, and there is little if any room to adjust. I did the paper trick when setting the gear-mesh. The unusual RPMs sound kept me from throttling into second gear. Any tips/tricks/ or advice is greatly appreciated.
Try tightening the slipper up more. If that doesn't do anything check the clutch and clutch spring In the clutch bell. Then if that doesn't work, tear out the trans and take it apart to check for stripped gears in there. I've stripped the gear on the inside of the slipper clutch shaft(inside trans) and it did what you are describing. Good luck!
just so you know, you do not need to disassemble the slipper clutch to change the spur gear. just undo the 3 bolts and swap out the gear and leave the adjuster nut alone.
Revo 3.3, EMBE 6s, ERBE 6s (x2), Summit 4s
Tighten the slipper to the point that with the input shaft locked your thumb will have nice indents from spinning the spur. The slipper clutch should not be confused with the clutch as they are two different components. The slipper absorbs the shock between the engine and the drivetrain and the clutch releases at lower rpms so that the engine can stay running when the truck is stopped.
The Super Derecho
Thank you fellas for the helpful suggestions. Will try to resolve the issue tomorrow. I'm much appreciative.