I have 2003 Excursion and I have a vibration that shakes the steering wheel very strongly and is very loud between 50 and 65 mph. I had to replace the ball joints so I have replaced a lot of stuff on the way in and out. I have upgraded to dual fox 2.0 steering stabilizer setup, rebuilt the axles with new seals and ujoints, new ball joints, new hub bearing assemblies, new warn premium hub assemblies. I have new rims and tires and have had an alignment done, i have removed the front driveshaft to rule it out as a cause for the vibration. What ideas do you all have as to where to look next? a couple of ideas floating around in my head are the rear drive shaft being out of balance, a bad rear drive shaft u-joint, rear pinion yolk bearing being bad, and someone mentioned a cracked flywheel? Would it hurt the vehicle to take off rear driveshaft and put on front and put it in four wheel high and drive up to that speed and see if the vibration goes away? Any help would be great guys... thanks!

 

No help on your question, but your truck looks great...

 

Thanks! I have been working hard on it!

 

Take off the rear shaft and take her for a spin. Lock in the hubs to make sure they will stay engaged.

 

Are your rotors warped? Tires out of round? If you grab rear driveshaft does it move?

 

May want to get the tires rebalanced. Had a bad vibration in mine and that was the problem. They were acouple of oz. over weighted..

 

The tires and rims are brand new balanced and alignment had been done... I will take a look at your other ideas... Keep the ideas coming thanks!

 

Motor mounts/tranny mount

 

First of all the front driveshaft doesn't even spin unless the hubs are locked in or you have 4WD engaged. So unless you drive around with your hubs locked there's no possible way for it to have been the front driveshaft. Could have saved some time there.

Secondly, the question as to whether or not you can drive around with front wheel drive has been asked before, and the general consensus was to take it easy and you'd be just fine. Most think that the front axle isn't designed to handle highway speeds as the only axle pushing the vehicle, but I have yet to hear of anyone breaking one either. Remember that our Excursions have a slightly weaker Dana 50 front axle as compared to the 60 mounted under the newer Super Duty trucks.

Did you do all the work yourself? Are you sure the front end is tight with nothing being loose or out of spec? Everything was put in the right way and torqued right with a good torque wrench? At this point I would suggest taking it to a dealer and have them diagnose; they have an alignment rack and ways of applying lots of force to the suspension in different ways to track down difficult issues like this. Sorry I couldn't be of more help.

 

Front wheels locked should be good up to 55mph

 

The vibration was there when got the truck before I did any of the suspension and front end work.. Yes I did all the work myself all the bolts have been torqued correctly and everything is installed correctly... The motor mounts are an interesting idea.. The tranny mount looks ok but ill grab on the tranny mount and see what I see... These are great ideas keep em coming... Thanks!

 

Btw I have a Dana 60 up front

 

"Looks ok" wont do it with a mount. Youd have to pull it and compare to a new one - at that point replace it. Did u drop tranny pan? Metal bits in pan? Loose torque converter?

 

wait - did you replace the stock axle? If the Ex has a 50, and you have a 60 - maybe someone did?

In another life I built a couple Jeep's and tracking down vibrations is a full time job. If it is fact front end (note that many times the vibe is somewhere else but you notice it in front end); here are my basic steps:
1. rule out wheels and tires. I have seen plenty of defects in brand new high end wheels and tires, I don't take anything for granted. The only way to truly rule this out is find a similar set of wheels and tires on a vehicle that you know has no vibes and swap them.
2. check pinion angle. The only reason this is second is because with a speed specific vibe it is almost always wheels/tires. Pinion angle is probably second for speed specific vibes. If the pinion angle has been changed from stock, you need to get it back. shim the axle mounts or drop the transfer case. Only ways to do it. (I noticed you said the vibe was there without front driveshaft, pretty much rules out pinion angle, but also makes me think you r problem is not in the front end.)
3. ball joints/TRE. I always think of these together. If you replace one, then you need to replace the other. Again, you can get bad examples of each. so test each after install, look for play in them, there should be none.
4. bent axle. Assuming you have done a reasonable alignment, the next most logical problem is actually a bent axle. Mostly because every thing that moves has been checked, so you have to start looking at stuff that does not move. A bent axle will, under certain situation cause the truck to act like it is out of alignment; despite being in alignment when on a machine.

Well - that is my list. Maybe some of that will help.

 

Great info jeeplj8, but I'd like to comment on this one:

The driveshaft doesn't spin when 4WD isn't engaged. So if this were a problem it would only vibrate with the hubs locked or 4WD engaged.