bhall1222

Ok, here's the deal. The rearend of my 2014 FX4 supercrew for whatever reason doesn't like to stay planted to the ground. Even on flat surfaces it still creates a vibration that is felt in the cab. I'm running 275/65/20 Terra Grapplers G2 (E rated) with a 2.5" RC level up front. Switched from stock rear shocks to Bilsteins and felt like it made a little difference, but now it's back to being rather noticeable.

IF I throw 300 lbs of stuff in the bed, boom, it rides like butter.

SO, my question is, what in the world do I need to do to get it to keep the rear end planted to the ground without any load in it???? Would getting the Rancho 9000s that are adjustable really make a difference? Does changing that shock stiffness end up keeping the bed from hopping up constantly? Or more of like a basic highway shock??

Only other option I see is maybe downgrade to a 275/60r20 (which I'd hate to lose my current size...). The Duratrac in that size is 45lbs, vs my current 57lbs. Pretty big difference in unsprung weight and maybe would prevent less bumps in the bed?

I don't know how more people don't notice this. My 2008 supercab with 6" pro comp road like a bentley compared to this fx4. Anyone who knows how to keep the rearend stuck to the ground, PLEASE feel free to let me know. Thank you so much in advance!

uzikaduzi

how much air do you have in those tires?... i'd try the chalk test to get the right contact patch... with higher volume tires, you normally need LESS air than is recommended with the stock size tires.

Fischer88

E rated tires plus over inflation makes it feel like your riding on solid wheels. Lower your pressure and it will help, but you best solution would be to leave some weight in the back or change to a p rated tire.

bhall1222

I've messed with the pressure between 35-45psi and honestly the lower pressure didn't really feel better. Rather strange. My 2008 had 35x13x18 E rated toyo open country ats and I never felt this with those, which is why it's bugging me so much on this truck and my 2012 was similar. Would love to not have to swap tires again...

keep the advice coming!

zimmer0

iTrader: (1)

if you're getting vibrations on flat surfaces it sounds like driveline vibration (grease driveshaft splines, pinion angle out of wack, etc.) Are you getting the vibes accelerating from a stop? Light acceleration? Heavy?

bhall1222

Really beginning to think I need to try a different set of shocks and see how they do. Something much more highway friendly, and not designed for off road like the bilsteins are. I've had them off road and sure they work awesome and can definitely see a difference, but that's such a rarity for me that I need to focus on the on-road comfort of my everyday driving.

So, what shock would you guys recommend for everyday use? As much as I think I want to steer clear of another "off road" shock, does anyone know with the Rancho rs9000xl, if you run it on the softest setting, would that be comparable to a good general travel shock? I do work for a boat builder and tow our skiffs but they're under 2000lbs so I don't see them being an issue with any shock, but I could stiffen those Ranchos up if need be.

Just want the truck to ride smooth on the highway. Next option is changing back to a D or P rated tire... just really hate losing my current 275/65.r20 size...

Thanks a ton!

MichiganFX4

I've only had my truck for a month and it's my first Ford ever, I love everything about it except for the bed bouncing around on every little bump, actually almost drove me crazy for 30 days, I was about ready to sell it already but decided to put some rear shocks on it first and bingo all the bed hop and shake almost is gone. I put fox 2.0's on if that helps.

MichiganFX4

bhall1222

Really glad to hear that you found a fix to the problem! I've seen great reviews on the Fox 2.0, and might have to try them.

Can anyone give me a comparison of the Fox 2.0 vs the Billstein 5100s that I currently have? Would I really see a noticeable difference? Would be great to not have to try 5 different shocks just to find the best one. But, I'm in the same boat as Michigan, it's driving me crazy!

Onelownismo

I'm having the same exact issue with a 100% stock XLT. Please let me know if changing your shocks fixes your problem because I'm really irritated such a new truck is riding this way.