Ok, just bought a maxx used, and it was locked in 1st gear when I got it (the person I bought it from tightened the screw down all the way). I backed it out and it was shifting quite nicely. Well after about the 8th tank, it just stopped shifting. I pulled it in, checked the screw tension and it seemed ok. Ran again, still wouldn't shift. I took the tranny apart and everything looked ok. Any suggestions? How many turns out from bottom do you guys have your 2-speed set to? Thanks in advance.

Tear it down again, and be sure that the shift finger moves freely, and that the spring is not smashed. If that looks okay, reset your shift point, then put a glob of Loctite on top of the setscrew. Don't put it on the screw before adjusting though, it won't hold. They have a habit of backing out.

Checked the arm (finger as you call it) and it's moving freely. I tightened it down all the way and backed it out to about where I had it before. If it backed out though, wouldn't it be stuck in 2nd? Well it's been stuck in 1st

Mine did about the same thing, and it was stuck in 2nd. It's hard to tell since the 2.5 is so powerful(I assume yours is a 2.5). Mine still pulled hard in 2nd. It may seem that the truck is in 1st, but it may be in 2nd. Also check the 2spd. bell, be sure the pin is still in it, and that the one way bearing is working/in correctly.

By the speed (or lack there of) and huge amount of torque/acceleration I can tell its in 1st. Which pin are you speaking of, the one that holds the two counter gears butt to but? They is there, it is a screw-type pin. The one-way is working just fine.

There's a pin in the bell that the 2nd gear clutch engages to.

Is your engine tuned right? If it isn't, it won't wrap high enough to engage 2nd.

Slipper slipping? Too much?

Re-RE-RE built the tranny again. The clutch finger moves in and out of the housing when spun (I Chucked the shaft in my drill to test it out of the transmission). When I put everything back together and went to run again and it still was stuck in 1st. I'm just going to buy a new 2-speed mechanism and be done with it.

To answer your other 2 questions, the slipper is locked to eliminate that from being a problem, and the engine is running perfect. I love this Sirio .18 Big Smoke

Good plan. Sorry I couldn't be more help, but it seems your problem stumped me. My next suggestion was going to be to replace the whole 2spd., but you beat me to it. I have no idea what's wrong with your 2spd.

Well, I swapped out the shifting mechanism and now it works perfectly, only now it's leaking fuel from somewhere. I shoulda just bought a new truck, with the money in parts I've sunk into this thing already...sigh. Can't wait for the LST

The LST looks sweet, I may have to get one.....

The standard setting are tightening the screw to make it shift later and loosen it to shift sooner. The easiest way to check the setting is to start all with the setting all the way in and loosen it a full turn until you hear it shift. If it doesn't shift at any point in the process there is a problem somewhere within. You can start by replacing the spring and appropriate washers. The last resort is buying the entire assembly.

He said he did all that....

From my experience it's usually not the truck but the person working on it. There either the 2-speed is adjusted wrong or the engine is out of tune. And if the person doesn't know how to do either I don't care how many times it's rebuilt.

You want to be careful tightening the the set screw on the 2 speed all the way in. There is a good chance it will compress the spring too much and damage it too much causing inconsistent shifting (or no shifting at all)