Just put an f350 4 inch block on my f250 and when I accelerate hard in first and second gear I get a bit of vibration. It mellows out and pretty much dissapears from 3rd on. I bought some tubing to make traction bars but want to make sure its not the drive shaft angle instead of axle wrap. Throw up a pic of before and after as well.
1st got truck

only pic of 2.5 inch level stock rear block

pic with f350 block installed

pics of block and driveshaft angle





stock block

tubing for traction bars. got a little extra. cheaper in baulk


1/8th inch. looks thin but the guy at the machine shop said he made a set for his father-n-laws pullin truck out of it and they lasted so I figure half the torque of that truck shouldnt kill them.

---AutoMerged DoublePost---

And if all it is, is axle wrap and I need to just do the traction bars do I go ahead and eliminate the sway bar? It looks like I can stuff them in there with it there but it might contact it.
Most highly modified stock 6.0 is what Im shootin for....not. Wife still isnt convinced I need an sct tuner yet.

 

Now this is just question don't get mad . Is that block set up factory for a F 350 cause it looks like a F 150 set up to me . I have a F 350 as well and my 3.5 block is cut out all the way around . I would thinking it's your pinion angle just looking at the blocks they look square no shim built into them . That's just a thought though

 

They came off of a v10 crew cab f350. They do have the pinion angle adjustment built into them. Pinion angle at pinion itself looks good but wandered if at the carrier bearing was ok.

 

I used the flat F350 blocks on my SC/SB, no issues here. My buddy had an 05 with 37's and a 6" rear spring lift, he had the same issues.

I'd say if it only does it when you get on it really hard, then it's axle wrap, but if it pretty much does it all the time until you're up to speed probably the pinion angle. Karl should have some more insight for you.

 

Sounds like axle wrap to me. If you cruising like 50 and mat the throttle does it vibrate? Unless the pinion is angled too far down or up. But the carrier bearing angle looks good to me.

 

What about the drop bracket for the drive shaft? Sometimes those need to be moved down farther, I always thought it was the u-joint binding up on my buddies.

 

That shouldnt make a difference until you go way up in height like a 4in and up lift

 

Yeah it is completely gone at cruising speeds. Only get the vibration on hard acceleration. I don't think my truck has enough ***** to get it to do it at higher speeds. At least not that I have noticed. Guess I will get after my traction bar build. Question now is to keep sway bar and traction bars or just traction bars? And should I do bushings or heims or both.

 

I'd do ladder bars personally, I think "traction bars" are a joke and really cobby, IMO. Two connection points on the axle, hooked to some sort of hanger up on the frame. That way it doesn't hinder wheel travel.

Lose the sway bar, most of our trucks didn't even come with them from the factory. You probably wont notice much of a difference. They're puny stock anyways.

 

Ive got enough tubing to make ladder bars but Im not seeing how it would be much different than making traction bars . To me having two spots on the axle and one on the frame would only be beneficial if you were taking off high speed in reverse. Not trying to be an a$$ just need a better understanding of the science behind it I guess. I measured what I would do for traction bars and it looks like around 6.5 ft of tubing per side. Im looking at using 3/4 heims at both ends with a mounting spot on the bottom of the axle and on the straight part of the frame below the suicide door. Ive seen plenty of dodge guys with it set up this way but.... lets just say I would like a fellow ford enthusiust to give me there experience with this type of setup.