I don't really think having a more powerful motor than a XL motor is going to put anymore stress on the pin. Only so much torque can be put through the transmission anyways, simply because too much will just flip the truck.

Weight, length, and front/rear mass ratio, and CG impact how much torque can be put through the system.

like ssspconcepts i also did this mod but i have yet to try it. but it seemed to work good and it is strong.

You are right...sorta...but weight of the truck and your slipper will significantly influence how much torque is transferred to/from the input shaft and eventually passes on to the rest of the drive-train. There are a lot of factors that influence how much torque is able to make it from the motor to the tires.

Yes, i agree more factors like terrain... grass, gravel, tarmac...

But generally, as far as the truck is concerned, that is what affects it.

I suppose shocks too, like for shock load, having loose setup will reduce the shock load, but that will also lower the CG when that happens... :019: :005:

ooooh, so many variables

I can't recall for sure what size now (2mm think tho), but yes, it was very tight and had to be forced thru w/a hammer. It was a real bastard to get thru :)

I have a 8XL running on 4S and 5S. Lots of TQ. Slipper is kept pretty tight so it doesn't slip and heat up too much. Overall I'm not that hard on the truck tho.

i used 5/64 and sanded a tad off and pressed it in using channel locks.

Thanks...its good info to have...now we have a bench mark for the 2mm key:027:

Now wouldn't it be nice if they came with the mod....

Well, you know... we COULD just weld it. It would have to be a good weld, to maintain shaft balance. Maybe just two tacks on each side?

I finally put the hex over to the input shaft .
Boy it was hard to put into with a hammer there is no way it will get slip and out of that hole,for a while I thought it will not go inside,I file it first just like SSS did suggest and it finally went all the way in to the other side with a hammer. here is a pic

Here is mine that I did. Guess what happens when your pin is to large? :026:

I had to use my old gear after I broke the new one! :035:
But it turned out very well, it was a very, very tight fit. I had to stop hammering it, and use a large vice to force it in. It worked!

Glad it worked out for you....looks good.

Oh, i forgot to mention, i used a drill bit end. I can't remember what size but i had to grind it down alot, the first one showed it wasn't ground down enough.:024:

So hopefully this stands up to my 7XL. The gear is actually to original gear from my first emaxx.... 6 years old! :005: Still looks as good as the new, only a little grime inside the gears.

I did some test runs with it and so far it is holding up really good thanks for the tip guys:027: