sokar

The stock tranny on my T Maxx Pro .15 refuses to engage. I took part of it apart, and put it back together as I remember it and followed the exploded view religiously. Whenever I give the car throttle, it will not engage, it just sits there and Revvs. The spur wheel turns, but apparently something in the Tranny is not engaging. I quadruple checked every part. Everything is in there and nothing is on backwards or seated improperly to my knowledge. What could be causing this? It was working fine before I opened it up. Could this be some sort of lubrication issue? The tranny is old, but it was working fine just last week and no gears are stripped.

DaveG55

If it was working fine why did you take it apart?

Oh, and my first thought -w/o knowing more history - is the owb inside the primary gear.

sokar

It seems like the owb is working. The gear will turn one way freely and bring the other gear with it when turned back.

I suspected a problem in the tranny, but later found out it had nothing to do with it.

tiemac

had the same problem. check the pin m3/12 in gears 4995. took mine apart a few times bought a OWB then noticed pin missing.

sokar

I have the old style primary shaft assembly. No pin.

DaveG55

You cannot check it by hand. It must be checked at speed/under a load. I check mine by hooking the input shaft into a drill and spinning it at speed. Mine went out with zero warning, working one day and not the next.
Of course it's always possible that there is some issue with the forward/reverse shifting mechinism or the forward/reverse gears - like the pawls are not coming out for example.
Since we don't know how completely you disassembled it, what changes/adjustments you may have made or if you put it back togeather correctly It's going to be very difficult for us to armchair mechanic it for you. What I would do is to carefully remove the front cover, attach the input shaft to a variable speed drill and slowly spin the transmission to see where the internals stop turning.

sokar

I guess the owb could be shot, but I think its a bit too much of a coincidence that it only stopped working when I took it apart. Something tells me that I did something wrong. The tranny does have a reverse gear, however the reverse has never worked on my T maxx. I don't care about reverse, so its no issue for me.

Could this be a lubrication issue? I have been fiddling with my tranny for quite some time, and much of the grease has come off the bearings, shafts, etc. I only ask because this exact problem happened with my Schwinn (bike). I could peddle all I wanted, but the bike wouldn't budge. Turned out to be a lube (or lack thereof) issue. Could this be possible in the tranny?

sokar

Well, I did the drill test and found out that everything was spinning as it was supposed to except the shaft that turns the wheels. The gear that connected to the spur spun fine and turned the bigger gear fine. That gear spun the gear that is on the shaft that turns the wheels, however the shaft that turns the wheels didn't spin. Any thoughts?

DaveG55

The Pro.15 transmission does not get much, if any, grease. It's made to run mostly dry. An excess of oil/grease will cause all sorts of problems like not shifting into 2nd gear, not shifting or engaging in forward or reverse and, coincidentally, causing the owb to slip.

The reverse not working makes me wonder if your problem is not in there. If you don't care about reverse then maybe you should look into a FOC (forward-only-conversion). That might take care of your problems right there.

sokar

I was thinking the same thing. How would I go about doing this?

DaveG55

The shaft that drives the wheels is the shaft that goes through the whole forward/reverse mechinism. Since reverse has not worked and you took it apart I would suspect that something is either caught, broke or missing in that whole drum, gear,pawl system. As I said above, I bet the FOC would solve your problems.

DaveG55

Buy an FOC, they come with instructions.

sokar

Will they sell those at my LHS?

DaveG55

Probably...
If not, here ya go
http://www3.towerhobbies.com/cgi-bin...?&I=LXCNA8&P=V

sokar

Thats all I need for an FOC? Jeez, it almost seems too simple.