Hello,

So one of my friends purchased a slash 4x4 in good shape off the ole' craigslist and the truck seems to be a pretty good deal but there are some handling concerns with the truck. I have a few ideas on what it needs but wanted some more expertise.

Truck Info: Stock Stampede tires (bigger then stocks on slash), 13 pinion 54 tooth spur, about 5-5.5 pound in weight, RPM a arms, aluminum casters & blocks, aluminum shock towers. If you need more information just let me know.

Truck ESC & Motor Combo: 3600KV hobbywing ESC & Motor setup

https://www.amazon.com/38010201-Max1...1CP6D7AD8X9VCJ

Problems:
1. Under-steer: The truck under steers horribly and i believe its because of the servo equipped in the truck. Its just a stock Traxxas servo in a black case. Traxxas# 2055 i believe? and it doesn't seem to be very strong, so i was thinking a servo upgrade would be almost a must.

2. Body roll & not driving straight: Now when on hard pavement, the truck body rolls a ton and i was thinking it was because of the need for heavier springs. To further explain why this is a problem, when on blacktop you cannot keep the truck driving in a straight line. I set the sub-trim, trim, servo rate, toe in/out, and camber and you cannot get this thing to drive in a straight line on blacktop, it begins to "pull" left so you correct and it'll pull the opposite or sometimes even the same way. Could this be related to the servo again, not being strong enough for the truck and maybe not centering to its zero point?

The truck is going to be a "monster slash" and used almost off road for its entirety, but when on hard clay the effects are also extremely noticeable.

any feedback is appreciated, thanks.