ok, first off my truck has no rubber to seal the doors, so thats a rattle.
is there supposed to be rubber there? if so how can i put new rubber in?

also above 40mph the whole truck begins to rumble,like under the seat. i was thinkin this was problably either badly balanced tires or a misbalanced driveline.

i know you can put atf in a unbalanced driveline, but is this recomended?

ive also heard of putting lead shot in your tires too, but???

any suggestions, any help appreciated.

 

Yes there are door seals that are supposed to be in between the cab and the doors and just about every parts vendors carry them. NPD has them for $14.95 each p/n- F-20518-1A (1-800-874-7595).

Check your U-joints on your drive shaft to see if they need replacing or possibly a missing balancing weight on the driveshaft or one of your wheels.

 

 

as for lead shot inside your tires dont do it. it will eat up the inside of your tire very quickly. there liquid balancers on the market for that.