Drevlin 0 Posted November 11, 2010 So I had a screw get loose that attached the motor to the truck and now that I re-tightened it, the transmission squeals like crazy in forward but is utterly silent in reverse. Does anyone have any idea what is causing this? I am experiencing no issues with the diff, fyi. Any help would be great Edit: I believe it may all be caused by the spur gear but I can't figure out why or anyway to fix it. Share this post Link to post Share on other sites
Singapore_959 18 Posted November 11, 2010 Loosen both motor screws a little and move the motor a little bit further away from the spur. The noise is usually caused by meshing the pinion too tightly against the spur gear. Aside from the noise it will eventually wear out the motor from overheating/stress. HTH KCs are fun! Share this post Link to post Share on other sites
Drevlin 0 Posted November 11, 2010 thanks I think it is closer to how it should be. While on tranny stuff. I looked the the Manual on the site and it says there were 2 spur gears in the kit a 77t and a 70t which one is the best for the cab? the 70t is what is in mine with a 18t pinion gear. Also will the sealed bearings in the gears wear out eventually? Thanks Edit: Is there a new 18t pinion gear I could buy that would properly mesh with the spur gear? I believe mine is wearing down. Like would this option work? http://www.horizonhobby.com/Products/Defau...?ProdID=RRP1018 Share this post Link to post Share on other sites
Madmuz77 19 Posted November 12, 2010 The King Cab uses the 77t spur gear, the 70t gear is for the Super Astute which uses the same tranny but has smaller wheels so can use a higher gear ratio. Using the 70t on a KC will still work with a larger pinion but this puts more stress on the motor & that horrible ball diff. I've had several King Cabs & i've been guilty of running the 70t spur myself, think I used a 19t pinion. I think i've rebuilt a KC diff so many times I could probably do it blindfolded Share this post Link to post Share on other sites
Drevlin 0 Posted November 12, 2010 Well that's good to know, thanks. I do still have a question of what pinion gear I can replace the aluminum with I noticed it was really worn down so would this work? http://www.horizonhobby.com/Products/Defau...?ProdID=RRP1018 is the King cab in 48 pitch or something else? Share this post Link to post Share on other sites
HunterZero 76 Posted November 12, 2010 Heheh. You're all saying 'tranny'. - J Share this post Link to post Share on other sites
Saito 5 Posted November 12, 2010 The King Cab uses 48 "metric pitch" which is not the same as normal 48 pitch. Robinson Racing does make steel pinions in metric pitch as well as regular. Share this post Link to post Share on other sites
Drevlin 0 Posted November 18, 2010 Thanks for the help with the gear from robinson. I have it installed and it is working perfectly, I never realized it could run so quietly! the old gear must have been worn sense I first received this truck. Thanks again Share this post Link to post Share on other sites