Anyone with an 80-96 truck with 6" of lift have vibration when they lock their front hubs? I think i'm getting vibration from my front u-joint angles and I'm wondering if anyone else has this too. When I get the chance i'm going to take the front driveshaft off and see if that vibration goes away but, anyone have this too?

 

i did but it was from the rear driveshaft angle it was too close to the lip on the gas tank so the yolk was bouncing off of the lip of the gas tank i shaved my t-case mounts on th crossmember to lower it seemed to fix the problem with no side affects

 

Well I'm talking about the front axle, because it's fine unless my hubs are locked. Thanks though...

 

Sounds like an unbalanced front drive shaft......might even be bent.

 

oppostite shaft u-joints are supposed to be set at the same degrees, which can change with lift. Lift can also affect your alignment and worsen steering problems causing this. First, check your alignment, and then for any visible worn parts in your steering or u-joints. Chances are you'll fix the problem with the alignment, or at least find something loose. If not we'll work from there.

 

Well this vibration only happens when I'm in 4wd, so alignment and all that doesn't matter. The front driveshaft is brand new, and has been balanced correctly. I was previously in an accident where my front suspension was damaged and the front driveshaft was bent.

 

I'd pull it and take it to a few different shops and see what they say....the shop that reworked it in the first place might have done it incorrectly (even thoug all you hafta do is heat it)

 

In theory, you are 100% correct. But I've found through experience that when you engage your front drive it can sometimes exacerbate an alignment problem you don't know you have. I know, doesn't make much sense to me either. Anyways, your course of action sounds like the right first step.

 

Justin, and thread readers,

I have the same problem. I just purchased a '90 F250 4x4 with a 4" Skyjacker Lift and 35" Tires. The front vibrates with the hubs locked. With no front driveshaft, and the hubs locked, the vibration goes away. It starts at 35 MPH, and rattles your teeth at 55 MPH. The kid that I bought it from said that it started doing that when he installed the lift. Does anyone know of a solution.

Thanks,
Jeff

 

Is it possible that axle drop brackets or radius arm(s)/brackets were bent in the accident? TTB drop brackets are prone to damage in accidents, the more drop the more likely damage . . . but what do I know . . . I'm not an engineer..

 

My F-250 had the identical vibration problem from the front end when in 4WD after a 4" Skyjacker lift was installed. The problem was due to an excessive u-joint angle on the transfer case end of the front driveshaft.

I installed a new driveshaft that had a CV joint in place of the single u-joint on the transfer case end of the driveshaft. The driveshaft required installation of an F-350 output yoke on the transfer case (simple job). The driveshaft was basically an F-350 unit with a CV joint. Any of the custom driveshaft shop should be able to fix you up.

When the new driveshaft was installed, the front end was quiet again. That driveshaft was installed in '95 and has worked flawlessly since then.

Lou Braun

 

Lou,

Thanks for the input! I thought that angle looked severe for a single U-Joint. Also, I talked with the Previous Owner last night, and he indicated that the driveshaft is rubbing against the crossmember. I looked at it, and there is a small area where it looks like it has been hitting, but the area has surface rust, and it doesn't appear like it is hitting very hard because there are no visible marks on the driveshaft. There is only about 1/2 inch of clearance between the driveshaft and the crossmember. I will grind the crossmember down a little, and if that doesn't fix it, I will head over to the driveshaft shop. What you said makes a lot of sense. I would estimate the driveshaft angle to be at least 20-25 degrees from horizontal.

Thanks,
Jeff

 

Jarch,

While you are down there with the grinder, look at the clearance between the passenger's side u-joint and the axle pivot bracket. There is very little clearance down there and the u-joint yoke can touch the bracket a little when it turns. As you might guess, this makes *lots* of noise and vibration when the hubs are locked.

I'd go for at least 1/8 inch minimum clearance between the yoke and the bracket. Just grind the edges of the joke - almost no material is removed and the strength of the joint is not affected.

I hope that you will be able to eliminate the noise with a bit of grinding. If not, the driveshaft swap will do the job. On my F250, there is about 1 inch of clearance between the driveshaft's CV joint and the crossmember. The original driveshaft was close to the crossmember but did not touch it.

Lou Braun

 

My entire suspension was changed (put in lift kit) after the accident, with new brackets and everything so thats fine. I'm starting to think it's just that I need a CV in the driveshaft.

 

Like said in previous posts your u-joint angles must be the same +/- a degree or so, otherwise you will need constant velocity joints at the case and possibly the front pinion as well. I had a front shaft made with cv's at both ends and it works fine with my 5" lift 89 F150.
Mark