Well... thanks for the details 2d. I don't know the real differences in the 4.1 version, but I believe there's many things that are the same. The 4.1 is like a .26 engine, in general. I think you gave me a clue to your probs, but I cant be positive without more checking up on things. The tranny's stock set up is always suited for the CB/spur gear combo thats been sold with it. That being said, it appears that the engine your running is having to turn more revs to reach the ingagement point when you have a shorter gear ratio. To make the ratio taller, We need to do at least one of two things. 1. Increase the amount of teeth on the clutchbell. 2. Decrease the amount of teeth on the spur gear. Or both. Right now, your running the shortest spur that hpi provides for any savage, I believe. You are also running a CB pinion thats only two teeth away from being the shortest CB hpi provides. Without even considering your mod question, I would say that you need to find middle ground for your gear ratio. The way it is now, it's likely too short to ingage the shift point, do you follow me here? In other words, the tranny needs to recieve more rpms to shift. This is done by gearing taller, so to speak. The more teeth the CB has, the more footage the spur will recieve. The less teeth the spur gear has, the more footage it will put out. I hope that made some sence. In short, Get a CB that has 17 teeth. Also get a Spur gear that has 47 teeth. For now, at least. I cant help the pin question because I don't know about it. Just be sure that you haven't changed the turns on the springs in the gears of the tranny. If you have, then set them back to factory settings. Why your truck doesn't work now is anybody's guess. 2dxtreme. You'll have to do a teardown and get it back in running order. There's refferences to manuals, blown-up illustrations, Parts lists, ect. If you don't have a manual for your truck version, Print one out either from our achive, or hpi's web site. I hope that helped, 2dxtreme.