I'm running LR C tires. With 35 psi.

 

If running LR C with a max of 50 you should be at 40. 35 is too low.

40 was the recommended pressure for LR C in 2004. On my 09, they are recommending 45.

 

The rated pressure on the sticker inside the door is 35PSI. Any more than that will change the geometry of the truck and effect the circumference of the tires.

 

That was for a p series tire, not a LR C or any other LR tire. The door sticker cannot be used when you change the LR of a tire. The door sticker also probably shows a P.../...R.. tire, not an LT.

As stated, my 04 came with LT275/65R18 tires LR C. The recommended pressure was 40 on the door sticker. My 09 has LT 275/70R17 LR C tires which are the same diameter as the 275/65R18. Door sticker for them is 45.

If the tire is a LR C with a max of 50, you need to use at least 40.

 

The maximum pressure on the tires themselves is 44PSI

 

Then it's unlikely it is a LR C.

A p series tire that is not an XL (extra load) would support the most weight at 35. Anything over that would only help with sidewall flex.

 

The problem with the ride is not with the tires.....it is something to do with the bed and/or the frame underneath.

 

When you changed shocks, did you change both front and rear or just rear?

 

Just the rear.....at the time, the front leveling Bilstein shock were backordered.

 

I too experience my rear end bouncing but mine usually happens when I am accelerating. The rear end starts bouncing then the whole truck starts bouncing until I slow down and slowly pick up speed. I have changed all my shocks with ProComp ES9000, run ProComp AT at 40 psi and installed firestone riteride airbags. I do believe it has to be the rear leaf springs which is the only thing I haven't changed yet.


01 F150 SuperCrew
6" fabtech 35" Procomp AT

 

Really? If you look out your back window while driving does it appear your bed is bouncing/jiggling more than the cab? Does it coincide with the jiggly feel? Mine does.

 

TJF150, sounds like you have some axle wrap. You have large lift blocks? Might be time to look at traction bars

 

When I do look out my back window, the bed jiggles slightly. But for some reason around 40-50 mph, the damn rearend wants to bounce around like crazy until I slow down. I have 4" lift blocks and traction bars already installed on truck. Everything in the steering system was changed out recently and aligned. I even changed out the upper control arms. This bouncing just started recently. Do you all think it could be lear springs? Just funny it only happens around 40-50 mph.

 

My truck is stock....so we probably have different issues.