Please Help!

[Legacy]

Hi all.

Just got my xxx-t sport rtr II. I'm trying to tighten the differential before running it. Problem is, I've lost my place and am not sure if it is too tight or too loose. I'm not even sure how to tell. I've done the whole thing where I hold the back right tire and spur gear and try to spin the back tire. It moves a tiny bit but I think that is just from a little play in the wheel. For the axle to actually move I have to turn quite hard. But, this was like this from the start. I have no idea how the diff is set now, I totally lost my place. Do you simply tighten it by putting the allen wrench in to lock it together, then turn the back right wheel forward? How do I know it is tightening? I do that and the wheel just turns and turns and nothing ever happens. I'm lost!

[always_opencarb]

turn it right ways and make sure the only thing that is moving is the screw its easyist if you take it outa the car

[Legacy]

Ok, I figured out part of it. I have it tightened now, I just wasnt holding the allen wrench in the screw slot and the diff was just turning freely as I turned the wheel.

My new question is this: One I push the truck along the ground, the back tires dont move very freely. They are kind of jerky like they are catching something repeatedly. Does this mean the differential is a bit too tight???

[Budman_222]

If the motor is in the truck you might be feeling the arm turning through the magnetic field. that can give that jerky feel when you roll the truck. it should be smooth without the motor in. if the motor's out and you get the jerky roll, something's not right. this site has a lot of losi manuals and setup tips. you might find something on there that will help.

http://www.teamlosi.com/exploded/index.htm

[Legacy]

Well, now i broke it. I was tightening the differntial and went too far. Now the back wheels spin independently of one another. What am I supposed to do now?

[racer234]

You broke it? Well start by pulling the entire transmission out of the car, and finding out what exactly broke, it may be as simple as a new diff rebuild kit, but you need to find out. The diff was probably set fine from the factory, all you need to do is get it 'hand tight' (basically dont get on it too hard, just until it feels tight) and then back it out about 1/8 turn. You can usually hear a loose diff when you run the car if you take off hard; it will make a horrible squeelish chirp.

[rocknbil]

No need to rebuild the tranny, it's new (correct?) The diff bolt probably broke. Replace the diff bolt, and you've just learned the one thing you have to be careful of with a Losi tranny.