• Welcome to RCTalk! 🚀

    Join the #1 RC community where hobbyists connect, share, and get expert advice on RC cars, trucks, boats, drones, and more!

    • ✓ Friendly & passionate RC enthusiasts
    • ✓ RC tips & troubleshooting
    • ✓ Buy, sell & trade RC gear
    • ✓ Share builds & upgrades

Transmission Problem? HELP!!!

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
S

SilentHunterKellen

Hardcore RCTalk User
Messages
1,855
Reaction score
2
Points
0
RC Driving Style
I put my new tmaxx tires on, put my triple rate springs on, cleaned my air filter, refilled my shocks, and I started her up. Took a couple warmup laps and bam! it hit me, she wasn't running to full potential. I took out the tempgun, and it read 160, so I leaned her out, and got it to a nice even 230. Now I slam the gas, and shes screaming but not going at a good top speed. I tried to tighten the slipper, tighten the wheels, whatever...but no such luck. So I decided to take apart the gearbox, and see if there is something wrong. -Got the gearbox open, and everything seems to be okay. So I decided to ask you guys. Anyone have a problem similar to mine? Anyone have any solutions? I really want to race tomorrow, but I can't if my top speed is 9mph. Please help me!:help:
 
CB and Spur gear mesh ok???

All drive shafts connected correctly??

Tires glued??
 
Just a thought but are your clutch shoes glazed over? Or maybe check the set screw for the 2 speed clutch. What tires were you using before going to the maxx size you may need to adjust your shift point.
 
Adjusting the shift point is a good idea, its 9:20 right now, so I guess Ill try it tomorrow! Thanks for the awesome idea. Ill also check he clutch shoes while my truck is in pieces.
 
I had my first serious drive train failure today, thanks to too much water and snow. I recommend that you check your slipper clutch assembly. The disk on the tranny side has the potential for getting fried pretty easily (at least when you add water). As a result of too much moisture and too heavy of snow, I zipped my spur gear and then fried my clutch shoes. I had seriously thought my tranny was dust, but everything looks okay.

So, I recommend taking a careful look at the surface of the spur gear closest to the tranny. Make certain it is not fried. The teeth of the spur might be fine, but the slipper mechanism that allows that rotation to be translated to the tranny might be messed up.

I also recommend giving your clutch shoes a serious once or twice over. While your at it make certain your clutch bell isn't overly glazed on the inside. Slippery surface does not work well when friction is required for proper engagement.
 
ok, well I'm taking apart my clutch bell assembly, and checking the spur gear. Any good hop ups to consider while my truck is in pieces?
 
You could go for a three shoe clutch (Mugen makes a nice one). You could upgrade your pipe, shocks, towers, anything your wallet can afford.
 
oh poop
big big problem.

I was running my savage after finally putting it back together, and then BAM! The engine went to like 28,000rpm and rising and I ran over and shut it off. I found on that because i was holding the brakes, the engine clutch bell stripped the spur gear, and now I am in need of another 52t gear. I have no idea why it happened, but I'm really angry because I have to take it apart once again.
 
Probably a stuck throttle. No time like the present to upgrade those spurs, clutches, and shoes. :D
 
no, the stripped spur gear is very odd, its stripped in about 2 inches of the actual circumference of the gear. Its not stripped all the way around, does this mean that something happened to screw up the gear mesh or something? Why would the engine rev so high when I even went over and closed the throttle manually, yet it still showed little signs of slowing...I dont really want to start the engine, only to find out that it blew up, is there a valid explanation to why the spur is striped in only 2 inches? Thanks alot skymaxx...you are being quite helpful in this most desperate time!:doh:
 
The strippage probably happened so quickly that the gear never got a full rotation. Once there are no more teeth to turn on, the gear will stop.

Were I to guess, I'd say your spur was tightened down too far and your clutch bell hooked up much more quickly and with too many rpms on it. This would cause the spur gear to resist rotation (especially if something locked up in the tranny or elsewhere in the drivetrain...for instance too large of tires ie Jumbo Kongs causing the drivetrain to work overtime) and the clutch would chew that plastic up pretty easily.

Did the vehicle move at all before the thing started to smoke on the rpms?
 
The beasty was moving good for about 30seconds then when I decided to floor it, the engine wouldnt slow down so I slammed the brakes, and all I heard was-sccchhhhhrrrrrcccchhhhhhhh!

*ran over and shut off engine*

"OH poop! My friggin spur gear."
 
I would seriously consider looking into the tranny case for anything binding or chewed up. If all is well there, then check the diffs for binding. Beyond that, I am betting that you destroyed your clutch shoes on top of the damage to the spur.

In order for you to chew up the spur gear in the fashion that you describe, the spur gear would have to have slowed down or be stuck in a position that would allow the clutch bell to remove the teeth from the spur.
 
Found the problem.
Turns out that the engine vibrations caused a screw on the plate that holds the engine mounts to come loose. That caused a way wrong gear mesh, which caused the engine to spin VERY freely due to the fact that the CB wasn't touching anything, and when it came back down, it hit hte spur and ripped it to shreds. there is only damage in a minor area because I was holding the brakes, so that explains it all. I thin I could have caused minor clutch damage, but most of the damage is the spur gear. I will also have to go pick up some screws and better threadlock for the enigne plate.
 
That will certainly do the trick. Glad you found the problem. I would have mentioned the mesh issue, but figured you had already checked that.
 
The mesh was fine when before I used it, when I was driving, the screw came out, and that is what caused the mesh to be wrong.
 
I always pre-flight and post-flight my rides. It is a quick check of all trouble-spot screws (like those holding the engine on) for tightness. You may want to add this to your RC running along with some better loctite. It might save you in the long haul.
 
Amazing how one tiny screw left unchecked can do so much damage. Lesson learned I guess - check and re-check your entire truck before running/bashing.
:hump:
 

RC Builds

Back
Top