Loosened the bottom bolt of the shackles today to 50 ft-lbs. What should I do about the frame ones? And what about the things (I guess they're shackles) underneath? I haven't touched those yet. Pics to show better what I'm talking about tonight.
The things underneath are your U bolts that hold the axle to the springs, Whatever you do DO NOT LOOSEN THOSE BOLTS !
I wouldn't run low air pressure it may make it ride smooth but it will damage your tires over time. Remember the Issue in the late 90's- early 2000's with Explorers flipping and rolling it the tires were blew because they were underinflated and broke down internally . THE ONLY TIME I RUN LOWER PSI IS WHEN I'm CRAWLING, Then I air up at the end of the trail.
Air Pressure - Correct, Underinflated and Overinflated
Advantages of Correct Tire Inflation
Maintaining correct tire inflation pressure helps optimize tire performance and fuel economy. Correct tire inflation pressure allows drivers to experience tire comfort, durability and performance designed to match the needs of their vehicles. Tire deflection (the tread and sidewall flexing where the tread comes into contact with the road) will remain as originally designed and excessive sidewall flexing and tread squirm will be avoided. Heat buildup will be managed and rolling resistance will be appropriate. Proper tire inflation pressure also stabilizes the tire's structure, blending the tire's responsiveness, traction and handling.
Disadvantages of Underinflation
An underinflated tire can't maintain its shape and becomes flatter than intended while in contact with the road. If a vehicle’s tires are underinflated by only 6 psi it could lead to tire failure. Additionally, the tire’s tread life could be reduced by as much as 25%. Lower inflation pressure will allow the tire to deflect (bend) more as it rolls. This will build up internal heat, increase rolling resistance and cause a reduction in fuel economy of up to 5%. You would experience a significant loss of steering precision and cornering stability. While 6 psi doesn’t seem excessively low, remember, it usually represents about 20% of the tire’s recommended pressure.
Disadvantages of Overinflation
An overinflated tire is stiff and unyielding and the size of its footprint in contact with the road is reduced. If a vehicle's tires are overinflated by 6 psi, they could be damaged more easily when running over potholes or debris in the road. Higher inflated tires cannot isolate road irregularities well, causing them to ride harsher. However, higher inflation pressures usually provide an improvement in steering response and cornering stability up to a point. This is why participants who use street tires in autocrosses, track events and road races run higher than normal inflation pressures. The pressure must be checked with a quality air gauge as the inflation pressure cannot be accurately estimated