I have some axle wrap from 0 to 15 mph. I have a 2003 Crew cab with a 6 inch lift and 35 tires. Is it that bad or should I install a trac bar? Thanks

 

Are you sure its axle wrap? What are your symptoms? Sounds like driveline shudder...

 

I agree with Bear Hunter.......seems like a lot of people lately have been confusing axle wrap and driveline shudder.

Does it happen every time you take off, even if you take off slowly?
Did you shim the carrier bearing?
Did you use blocks to lift the rear? If so are they flat blocks?

If you truely have axle wrap when you punch it traction bars are the cure for that. My truck used to get real bad wheel hop any time I punched it taking off on a turn. Installed the traction bars and now the rear wheels stay planted and spin.

But, if it's driveline shudder you'll need to play with shimming the carrier bearing. If that doesn't work you can always get a custom made rear driveshaft.

Also, what motor do you have?

 

My truck is
2000 Pwr Stroke F250 4x4 crew cab, 5.5 Fabtech lift, on 35's. 4" exhaust, Chipped, K$N filter, oil crossover,tri-cumulator springs,upgraded fuel reg. spring.
I have am experiencing the same.
I do believe that it is the carrier bearing angle/height
I replaced the carrier bearing, it looked worn, so i changed it figured that might be the problem, but it didnt help. I have install all new U-joints also to elim that too. Truck has 90K on it.

My truck does the shudder from 0-15mph then quits,
When i pull the shudder is still there but not as noticable.
I have no wheel hop, course i havent tried foot braking the truck to try and burn out either.
I have made a shim 2" thick, going to start there. Im going to shim the carrier with it, to see what happens.(any thickness suggestions?)
I have been told also that it is axle wrap. but figured the shim was the cheapest thing right now to try. Plus it feels like the driveline anyways.
I know if i roll out from the light, and floor it, it will rattle your teeth it vib's so much.
I have looked into the Fabtech ladder bars, they look like very nice pieces to buy.

any help or?

 

The general rule of thumb is use a 1/4" of shim for every 1" of lift you have. So I would start out at 1 3/8" of shim and go from there.

Fitter

 

I agree. If it still vibes from a take off add a little more shim....if you start to get a high speed vibration take a little shim out.

 

thanks for the information.

 

I spaced my driveshaft carrier 1/4 for every inch of lift as well but i still have a vib at takeoff. My block in the back is angled and it points the pinion/yolk up too high. Should I remove it and place a non angled block in it? I have a 5.5" block that is 5/8 inch shorter on the front side (not sure what degree it is) any suggestions. I have a 6.5" procomp lift on it. Thank you

 

If you have a carrier bearing I'd try the flat top blocks.

 

Just a couple of things to help everyone. I had the same problem, and fixed it.

#1) for 6" of lift (spring or block) you do not need track bars. In fact, good luck finding any. Most are custom made.

#2) the idea of 1/4" for every inch of lift is not exactly true. I have 6" of lift, and I had to drop my carrier bearing a full 3 inches.

You have two ways to shim. First you can find the 1/4" shims, stack them, bolt them up, remove or add shims to cure vibration. Or you can get an actual bracket (this is what I use), as long as it is measured properly. I got mine from Superlift, and it was a perfect fit. I went to the dealership and asked them to print out the pages referring to drive away shudder. They gave me several pages of driveline angles, proper shimming, and tolerances. That way I could check the bracket as I installed it for the right fit.

The main thing is that the center u-bolt cannot have an angle. I don't have the cheat sheets any more, but I think the tolerance was like 1.5 degrees. The ends could have at max a 3 degree difference in angle. So the driveshaft angle from the tranny and the angle into the differential had to be within 3 degrees of each other, and the angle where the driveshafts met in the middle had to be less than 1.5 degrees.

From what I figured at the time reading the spec sheet, anything beyond 6" of lift and you more than likely cannot get rid of drive away shudder unless you went to a one piece driveshaft. 6" and less, and it wasn't a problem.

 

Oh dear. Wrong. You may need them with no lift as no two sets of springs are the same. Fabtech and about 6 other companies that come to mind make traction bars that will fir no lift up to 8". Check your facts, please.

You're right. This is a starting point or guideline and like most guidelines ,does not apply in all cases.
Again, not so. When running a two piece drive shaft (and I've done it in a few vehicles you can have angle on the first shaft.
Also if you think it may be the shaft and you have done everything else, do yourself a favor and spend the 40 bucks to have your shaft balanced. It will work wonders and is often the cheapest fix.

 

CWB, the info I posted was just from my own trial and error and worked great. In fact, my truck takes off smoother than my parent's stock F-250. I had two different 4x4 shops tell me that I had to have track bars and that there is no way my driveshaft was the cause of all that drive away shudder (my driveshaft was already shimmed at the time using the 1/4" for every inch of lift rule). Both shops checked around for track bars for my truck, and neither shop could locate any, but offered to make some for me. I checked with Superlift and Edge, and both companies said that my problem was the carrier bearing shim, and that I have the wrong angle. I checked with several different companies on the phone and online and had a difficult time finding track bars for my truck. My solution was to get the spec sheet from my local Ford dealership, and measure the angles of the driveshafts myself just to verify that was the problem.

Also, just an observation, I thought an unbalanced driveshaft would cause vibration at speed, not at take off. Correct me if I'm wrong, but I've never seen or heard of low speed vibration (10 mph or less) caused by unbalanced driveshaft.

Anyway, what research I did and the things I fixed on my truck worked. It may or may not help these other guys out, but at least they have some options now. It just seems they are fighting with the exact same problem that I had, and I hope they get it fixed.

 

Happens a lot.

 

I am going to the dealer to get my specs from the dealer as soon as I get back from the desert. After I find out the correct angle it sounds as simple as adjusting shim height to adjust the center u bolt angle?
Thanks for the help

 

Regardless - the traction bars will not hurt and can be an assett. Although custom made ones are good, and may save you some money - assuming that you have the skill level to fabricate them - there are several companies that make them too...

One easy way to tell if it is axle wrap it that it should occur when torque is placed on the drive train where as unbalanced drive shafts and improper drive line angle may or should be constant at a given speed.

Just remember too that axle wrap can also cause temporary drive line angle issues too. Shims may cure the problem but trac bars will definately cure it...