How mich lift are you putting on the front of your truck? As you lift a truck, you inevitable change the geometry of the driveline. The more a truck is lifted, the more the geometry is affected between the transmission and the rear diff. If not corrected, vibration can occur in the driveline. To make up for this change, shims are added...most lift kits come with shim kits. As a rough start, a 1/4" shim is added per 1" of lift. From there you have to drive it around some to see if it gets rid of driveline vibration.

 

I didn't lift the front at all, just the rear end with the 4" blocks. I just wanted some extra room for the truck to sag when pulling a trailer, and the lift blocks didn't come with any shims.

 

What are your symptoms exactly? Wheel hopping or driveline vibration?

 

I was just checking out the lift blocks that i used (ReadyLift 2011 Ford F250 Super Duty 4" Rear Lift Block Kit) and it looks like they build the angle into the blocks to correct you pinion angle.

 

I get driveline vibration briefly when I accelerate hard from a dead stop, of course this is more noticeable, and lasts a bit longer when I'm pulling a trailer. Also when pulling a trailer around 110kms/h, but only if I'm holding it in 4th gear at the speed, I get quite a vibration. Haven't had any wheel hop though (yet).

 

Vibration at a constant speed sounds more like what I was talking about in regards to carrier bearing spacers for your driveshaft. I would call the guys at ReadyLift and let them know what's going on. They seemed to be helpful when I called them about my fitment.

 

So I talked to the guys at ready lift today, and they said they've heard cases of this happening with long bed trucks because it's a two piece driveshaft. They told me that I probably need to shim down the carrier bearing in order to correct this problem. So I added about 3/8" of shims but I still have a slight hint of vibration, and going by what you said RAPR, I need to add about 1/2" for the 2" I lifted my rear end. So we'll try again tomorrow and see what happens. Thanks for the help RAPR and everyone else.

 

No problem. The 1/4" per 1" of lift is just a starting point....from there you just have to shim it out little by little, until the vibrations disappear completely. Good luck!

 

Can anyone give me some insight here? So, I bought a leveling lift for my 2010 f150 4x4. It's 2.5" up front and an additional inch in the back. When I bought it, I didn't realize the rear block in the kit is meant to stack with my stock block- so it would be the stock 1.5" block stacked with a 1" block. I assumed it was a 2.5" block that came in the kit, but ig that's what I get. I don't plan on offroading or towing. It's for looks. Should I go to the trouble of returning the kit?

 

There is nothing wrong with adding that block. Stack it....

 

lefonz your swimming in the wrong lake come to the F150 side......and yeah that block is fine.
Also 2.5" is about what it takes to level it do you even.need a block in back?

 

Well, I want more of a slightly higher stance, but with not as much of a rake. Btw, I just found this thread and assumed it went for all fords lol

 

I'm at a crossroad. My rear end is sagging compared to my front just a bit over an inch. I have a tuff country leveling kit up front 2.5 with a spring off a 2015, but nothing in this rear. Do I do a 1in add a leaf or a 1.5 block or? I think my block in the rear is out of an f350 it looks to be just short of 4in. I do tow a camp trailer but mainly its to haul the fam and dog, and Home Depot runs. Please give suggestions big camping trip coming up.

 

Most of the people complaining about axle wrap are actually having a pinion angle problems. Almost all blocks should be flat but almost all kits have tapered blocks. Flat blocks are for 2 universal joint driveshafts. Tapered blocks are for driveshafts with a double cardan joint.