LouDawg, from looking at that pic, I can clearly see that the pully was put on backwards. that is why it rodeoff and melted to the case. You can see that the ridge on the inside of the bully is facing away from where it mounts. If you flip the pully, it is captured by the bearing so that it cannot ride off.

Yes, I forgot to mention that!

The issue does in fact lie in how the tensioner is mounted. Front tensioner in mounted to plastic, rear is mounted to motor mount. Combine the fact we run beastly motors now and not to mention a crappy bearing in the tentioners, its recipe for a weak link in the drive line.

It could even be possible that the bearing in the tensioner is creating some amount of heat that ends up transfering to the bearing shaft--> then to the mounting area of the tensioner which is... PLASTIC!!

Im just trying to look at it from all angles. I noticed that finding the right amount of tension on the belt is very important.

Hmmn ill have to look at the busted part again. If im not mistaken I thought there is only one way the pulley can fit on the bearing?

You can put it on the right way or the wrong way. What your pics showed us is the result of the wrong way. I have seen them put on backwards from several local people, it easy to do.

Think about it this way. If you mount the bearing only to the puly tensioner, then slide the pully over the bearing, the pully can come off the same way. The ridge that captures the bearing must face or go on facing the post on which it mounts. Makes sense?

I understand. I could have installed the pulley incorrectly.

Nope... you can install it either way... right and wrong way.

I ran mine backwards for two months without any issues. Then one day the belt kept falling off... that was the issue. flipped the pulley and replaced the belt covers and never had a belt fall off since.

too slow on my post! LOL

Hopefully that is the issue and gets you situated LouDawg.

Got it.
The Manual is misleading kit builders beacuse if you look at the doglines you would think the order of parts instalation would be
1. Bearing cam
2. bearing.
3. Pulley
4. Screw.

I just followed the instructions. =/

so what is the right order? I guess I am just missing it and I don't have an SC104x4 in front of me right now.

Looking at the pic, I would think the order LouDawg did based on his description is what I would have done too.

It is misleading. I bet you there a a ton of others that have their truck buit like that

The guys are saying it should be, and I agree.
1. bearing cam
2. Pulley
3. Bearing
4. Screw

so if I am understanding the issue correctly, the bearing has to be put on after the pulley so it locks the pulley onto the cam after you add the screw.

If not, the pulley can just come right off with the bearing still attached to the cam?

Is that right?


Another question, and I appologize if this is easy to see with an SC10 4x4 i front of you which I don't have, but can you run two bearings then and just use a longer screw? If so, would that provide any benefits / support?

Regardless of the way I installed my pulley lol, I do believe and witness some flex on the front tensioner if the tension is set too high.
This will eventually cause the pulley to ride off (if installed correctly) or cause premature wear on the lip of the pulley (if installed correctly).

Yes thats sounds right.

I dont know if two bearings will fit, but i can try when I get home.

BTW Thanks you guys for the all the help and quick input!!!
I noticed the last few pages of this thread had a negative vibe towards people having issues with our toy trucks.
Its can be intimidating for the newer guys to ask legit questions.

IMO it's not enough capacity for the 4w. However, that has some real punch if you own a SC10 2w - particularly if you want to put the radio gear down the middle.