Problems with hitbox

Help and Feedback Scripting Support
1

Hello! I dont really get why is this happening, but as u will see in the following video my cart is behaving weirdly (shaking), because of hitbox.
robloxapp-20200621-0001461.wmv (3.3 MB)
The problem occurs when the cart is driving on the road, I don’t see it doing that while driving on terrain (maybe those shakes are not so strong and noticeable).
Here is the script:

local hitBox = Instance.new("Part", script.Parent)
hitBox.Name = script.Parent.Name
hitBox.Anchored = true
hitBox.Size = Vector3.new(8, 4, 10.75)
hitBox.CFrame = script.Parent.BasePart.CFrame * CFrame.new(0, 0, 0.25)
local boxWeld = Instance.new("WeldConstraint", script.Parent.BasePart) 
boxWeld.Part0 = script.Parent.BasePart -- base part is the main part of my cart
boxWeld.Part1 = hitBox
hitBox.CanCollide = false
hitBox.Transparency = 1

If anyone knows why is this happening please help!

2

Make sure your wheel Attachments are at the center of the wheel otherwise you will get a wobble like that.
Make sure your Wheel and the Part they are attached to are about the same weight using Density. If they are not the same you’ll get the HingeConstraint shaking.
If your wheels are contacting the Parts of the car they’ll bounce as well. You can go into File>Settings>Physics and look for something like ShowContacts. That will display a red sphere in Studio when testing where two Parts are colliding, very useful for vehicles.

3

hitbox is now massless and it seems to work, thanks!