Ofna 2 speed shifting problems

[herbykw]

Hello everyone, I'm new here. Just thought i would see if you could help me out. Heres the story.

I got a used Ofna Hyper One Seven, the 7th scale onroad car with 2 speed and reverse. I ran it for a while, then it sat for a while and i couldnt get it started. I took it to a shop and they told me the engine was bad. I bought a Brand new Ofna Force .26 and put on it, now whenever i get into the throttle it moves quick until it shifts into second gear, then it just revs up like it in neutral and coast to a stop. Once the engine gets back down to idle, it kicks back into first and will move again. I call the Ofna tech support and they told me it was the 1st gear one way bearing. I ordered the part number they gave me and took my car apart and it was no where near the right size. any thoughts? Thanks in advance

 

[olds97_lss]

If it was your first gear OWB, then it wouldn't move at all... Sounds like something is wrong with your 2nd gear mechanism.

Unless it's the opposite of every two speed I've come across.

Got any photo's of it? Can't seem to find a manual.

I think this is you too?
http://www.rcuniverse.com/forum/m_10308555/tm.htm

Appears someone was nice enough to post photos of their manual. It appears OFNA expects you to remove the OWB from the assembly and press the new one in. A bit odd, but I know guys do it.

Regardless, I don't think your issue is with the OWB, but rather the two speed pawl (red)/shift assembly (green) or the pins that the pawl swings out and catches on (yellow):

Suppose I could have made the image a bit smaller... The OWB in a two speed engages and locks on the shaft when your in 1st gear. Once the RPM of the trans gets up enough speed to kick in second gear, the pawl (red) swings out and catches on the pin (yellow), then the OWB lets go and 2nd gear takes over via the mechanical link of the pawl/pin.

Or, it could be the set screw on the entire pawl disk (green) that locks it onto the shaft. If that set screw isn't locking that disk onto the shaft, then when the pawl swings out to engage, the disk just spins on the shaft vs spinning the shaft with it. Now that I think about it, that's the first thing I'd check, the second would be the pin that is in yellow. Those have a tendency of rattling loose/falling out.

That's a fairly typical two speed assembly. Like the one in my jato, savage, revo and like a t-maxx. At least the general premise is the same.

UPDATE: I edited the photo and circled the set screw I'm talking about in an "aqua" color.

 

[herbykw]

Thank you. I haven't checked these threads in a while. The first time I took it apart I forgot to tighten the screw back in. Woops. It worked great for a while, but now it's not engaging again. I think the screw came loose. I will check it out and replace it if needed. Thank you again