"Roller" won't roll?!?

[TagRC]

Hey guys. I'm new to RC and to RCCrawler, as such move this to the newbie section if it doesn't belong here (I wasn't sure where to put it).

Got my first RC (SCX10 Wrangler G6 Kit) - just spent 7 hours building and should be in the roller stage. I haven't purchased any electronics yet.

When I push it, it'll roll about 6 inches and then it locks up...it will then roll backwards 6 inches back to its starting point and lock up again. Is my slipper clutch not set right? Or did I screw something else up? Please help give me a starting point for troubleshooting.

[allanon1965]

Disconnect one driveshaft and try again...if it still does it then disconnect the other...if it still does it then it has to be in one of the differentials...pick one end off the table and try again....just like the driveshafts...that should narrow it down..could be the gears in the differentials have some residual flashing on them..could also be in the trans gears if it rolls fine with the driveshafts removed...coukd also be a bearing issue although its not as likely

[GodSpeed999]

Good diag tip above.

I'm willing to bet it's friction in one or both differentials. Make sure the pinion gears are seated well and when you spin them (meshing with the ring gear), they're nice and free.

And definitely double check that your driveshafts are phased properly (pins at each end face the same way)

[forty2]

Driveshaft phasing is my first thought, easiest thing to fix too.

[TagRC]

Thank you all for the help. I followed the above steps and discovered it was my fault. I had the wrong length grub screw holding the driveshaft to the transmission on the side of the spur gear cover and it was hitting the cover. It's all fixed up and rolling now...

I did notice while I had it apart though that some of the teeth on the plastic gears in the transmission seem a bit out of whack. Doesn't look like they are going to last too long so I'll order the metal ones right away so they are on hand when the plastic ones fail.

Thanks again!

[TagRC]

Oh, and when you guys say "driveshaft phasing" are you referring to the lines on each half of the shaft matching up when you put them together?

[guido5526]

Check the set screw for the rear driveshaft at the trans. I had the same issue and found the screw can go into far and contact spur gear back plate.

[Eric0424]

Originally Posted by TagRC

Oh, and when you guys say "driveshaft phasing" are you referring to the lines on each half of the shaft matching up when you put them together?

Yes, but also when you assemble the locker in the transmission. The holes for the screw pins holding the driveshaft should line up.

[duellym]

check your pinion angles on the drive shafts they might be binding

[Eric0424]

Originally Posted by guido5526

Check the set screw for the rear driveshaft at the trans. I had the same issue and found the screw can go into far and contact spur gear back plate.

Originally Posted by duellym

check your pinion angles on the drive shafts they might be binding

Read post #5.

[duellym]

oh i didn't see that