does anybody know the reason why my truck does this?

[blueb8llz]

Originally Posted by hoovhartid

Have you tried holding the truck up in the air and pulling the throttle to see if you have excessive wobble in the wheels. Or to see if one wheel balloons up more than the other? Or to see if the wheels turn?
Have you moved your steering while throttling the truck with the wheels in the air?

i have done this before. and now im traumatized lol. one day i flipped my truck and it was on its lid. so i decided to give it some gas just to see how much my tires ballooned. to my surprise, it ballooned a decent amount and i ductd tape my tires. i noticed that one tire ballooned alot more than the others and then....pop!! that tire got all unbalanced! unglued the tires to see that the foam had ripped in half. this all happened before my problems started.
since then, i replaced that one tire with new tires and foams.
so now when you tell me to do what i did awhile ago, im scared haha. i mean i can take it easy on the throtttle but i dont know when is too much, cus when i did it the first time, i wasnt even gassing too hard.
im really starting to think you guys are right, it miiiiight be the tires unbalanced. cus i just turned my truck over and i gassed it, all tires spinning good and balanced. but i didnt really gass too hard, the more i gassed it, my truck started shaking, but the tires were still straight. but this is no where as much throttle as i would give it if the truck was on the ground. so maybe if there was more throttle, i could maybe see some flaws with my tires...hmmmm.kinda worried to check that out. but we might got a good idea now...it could be the tires.

Thats easy to test - if it is the tires, swap sides with them - put LF on the right front and the LF on the right. Same for the back. Now it should pull left. Simple to test, should take little time.

I don't think its tires, as badly out of balance as some of what I've run have been, I've never had one act this way. More possible is BrianG's suggestion that toe is off. Unless trx has changed, they come with 0deg toe on front and 1deg toe in on the rear. Caster is set with caster blocks or spacers, are they still there and in the same place on both sides? Camber is the angle the tire makes with the vertical viewed dead on. These would have to be pretty far out of whack to cause your prob, so it should be readily apparent.

Drive pins - there is enough tension on wheel axles to drive a wheel until you reach enough speed that a missing pin will prevent that wheel from staying in synch with the others - then it will veer off straight line. Pins are all or nothing. If one starts to back out while running, it usually hits bulkhead and you'll def know it. I have seem then fly out and not touch anything, pin's just all of a sudden gone. Again, an easy thing to check and eliminate as a possibility. Have you checked all wheel bearings? Another easy thing to check that could be causing this.