Originally Posted by 5VoltDetonator
ok after switching the steel drive shaft I see allmost no difference. It is still pushing the ass end out to the left hard when I get on the power. Now I think I know what the problem is I think my gear case is bent or tweaked or something.
If your car is always spinning out to one side, then the problem is usually a chassis tweak or weight imbalance. The way to test it ideally is to use a tweak board, or you can do it with the coin test.
Put the car on a flat surface, and press down on the chassis to settle the car. Put a dollar coin on the top of each front wheel, and then lift the front end putting a small screwdriver under the exact centre of the front of the chassis. Very slowly lever this up until the front wheels lift off the ground. The aim is for both front wheels to lift at the same time, shown by both coins dropping off the wheels simultaneously. If the tweak is incorrect one front wheel will lift before the other and that coin will drop off that front wheel first. If this happens there is a tweak in the chassis somewhere that you need to sort out. If both coins drop off the wheels at the same time the car will be balanced and should steer the same.
If the chassis is tweaked it will never run right and you need to work out where the problem is. Check the car has been built straight. Take the wheels off and loosen the top deck screws. Now put the car on a flat surface and while pushing it down tighten the top deck screws, this should square up the chassis. With the chassis sitting on your flat surface measure how high the front axles are from the surface to check the front suspension isn't tweaked. For the rear end take the pod off the lower plate and remove the axle. Now loosen all the pod screws, put the pod on your flat surface and tighten all the screws while holding it down. If when the pod is screwed together it still rocks on your flat surface it is twisted and needs replacing. Assemble it again and it should be built straight.
If there are still problems check the weight balance, motor choice can upset the balance of the rear pod, for example I run with brushed motors and need to add 30 grams of stick on weights to the left side of the pod to balance the weight out. Also make sure the motor wires aren't pushing the pod over and restricting movement.
Check your diff is smooth and adjust it so it is free. Loosen the diff, hold the rear axle by both wheels and try and push the spur hear with your thumb. If you can move the spur gear tighten the diff a little and try and turn the spur gear again. Keep on going until you can just move the spur gear with a good amount of force. The diff should be set now, so the diff action is free but the diff won't slip under power.