Ok guys I have a 2.5r Tmaxx with the black trans. Some of the gears in the trans got stripped out so I replaced them. It ran great one time out, then it sat for a month of so. I took it out, it wouldnt go forward, so I tried reverse it worked a few grabs of the throttle and then nothing. The engine just revs now in forward and reverse. I opened up the trans and all the gears are intact, Im stumped here. Any ideas that I could try?
Sounds like you sheared off your forward/reverse primary gear mounting pin. Its designed to fail under heavy loads but will occasionally snap prematurely. Next time you pull your tran's apart check the pin that holds those gears onto the primary shaft with the 2 speed gears and see if its snapped off inside.
There are alot of moving parts in those transmissions really. If thats not it there are alot of other things to check, but from my experience thats a pretty common occurrence.
Just make sure you check the easy things first. Make sure the slipper just isnt too loose or the shift linkage isnt stuck since both are much easier fixes if thats the culprit. Also, remember that spinning the spur gear by hand on a black Maxx trans wont turn the output shaft because of its internal clutches.
The clutch shoes and springs I put in when I replaced the stripped trans gears, which it did run a full tank full before I parked it.
The spur is definietly spinning with the engine. I have adjusted the slipper tight and loose wth same result. I changed the shifting servo as well because the stock 2018 was working very slow, still didnt help.
Where would I find the primary mounting pin and would there be something noticeable that I could do to test to see if it was broke, like turn a certain gear? I will definitely be taken apart again.
Also is there any upgrades that I should do? Single speed conversion? forward only conversion? Torque slipper upgrade?
You said you had it apart and replaced gears. Leads me to believe that the 1st gear hub, 1 way bearing is installed backwards or damaged. The complete hub can be purchased from your local hobby shop for around $20.
If installed backwards or damaged it more than likely will not drive forward or reverse, at least not at any kind of speed.