Spline looked fine to me. The whole two piece drive shaft with spline were balanced and inspected by the driveshaft specialist. Rear springs, I gotta check that out! My main concern right now is the scraping sound from the front pass wheel

 

To do IMHO:

1. Lock your hubs and leave in 2HI run up to 70 see if you have vibs. If you don't its inner axle bearings, spindle bearings, $30 part

2. Pull that rear driveshaft out and put the ujoints in your hands and see how they move? Freely both ways? You said it's balance so if they feel fine off the truck and all else looks good it's probably not the driveshaft.

3. While it's off checkthe tranny and pinion outputs, any play up and down? Any leaks?

4. Check your spring packs, u bolts and make sure nothing is broken or lose.

5. Check that slip yoke in the rear shaft and grease it while it's off. Be sure you don't have any spline damage.

6. All that checks out then look seriously at new hub units up front. Common sense is the only tangible issue you have found is the sound in the front hub. But 1-5 are cheap and not much work to check, so check them first and make sure, if all are good then I think you need to consider front Hub unit/s. #6 will get in your wallet a bit

And I will add - put an angle finder on that rear driveline and measure it to be sure. Eye'n it is a bad way to check.

Just IM female HO

 

1. Locked both end and just driving to 45 mph felt real rough and shakey, didn't feel comfortable going freeway speeds.

2. Already did as you mentioned. I removed the shaft and changed all three u joints checked the spline, greased the spline, all after it was professionally balanced.

3. Tranny side looked fine, axle pinion seal looks like there is some oil seeping out, no drips forming. Felt solid when drive shaft was off.

4. Will inspect those tomorrow.

5. See #2, grease and good to go.

6. My knowledge of 4wd hubs is minimal at best. But I suspect it is the 4wd hub because the wheel bearing hub rotates constantly regardless if the 4wd hub is locked or on the auto setting.

Where do I find an angle finder?

Question: if indeed the 4wd hub is going bad does that mean my front axle can engage at random? Let's say at a the magic 72mph? So, at 72 mph my hub goes from auto to locked, axle engages, thus causing bad vibes????

 

It sounds like you do have a front hub issue, I think you need to get that front end up and get the lockers and the hub units off you can find several "how to's on this site.

Here is one
2004 F250 Super Duty 4x4 from another site.

You can buy a $7 angle finder at any home store.

 

I address the locking hub issue yesterday. Being a perfectionist and impatient doesnt help my wallet. I went and bought the hub bearing assembly before even confirming the problem. Last night I disassembled the tire, pads, caliper, clipper brackets, hub extensions, and finally the locking hub. After removing everything, I Spin the hub bearing and it is smooth. Turns out the locking hub was bone dry and the needle bearing inside the locking hub was really spinning dry. Guess ill have ro return the hub bearing assembly. I cleaned and lubed up the locking hub, went for a test drive and the truck rides 50% better @70-75mph. My next chance im going to lube the other locking hub and I'll report back.

 

Add road force balance to the list of no effect. The mechanic said my front tires are scalloped and most likely my shocks are done. He recommends I change my front shocks and steering stabilizer because it was leaking.

 

My truck had the vibration a while back around 75, then it got worse and I started to go down the list trying to figure out what it could be. Well, I brought my truck into my local discount tire to get a flat fixed... ran over a nail. I got my tire fixed, and had all 4 tires balanced and rotated... vibration GONE. Truck drove smoother than it's ever driven in a loooooong time.

 

If you have bad tread wear then I'd be looking at the following:

1. Alignment
2. Ball joints

Both can cause bad tire wear and vibrations.

To check the ball joints jack up a tire just off the ground and try to move it up down and see if it moves. You might need to use a pry bar under the tire to get enough leverage.

Steering stabilizer and shocks are probably needed but my guess the fact that they are worn is the reason you are now feeling this, it's not the cause but them starting to fail is now showing your symptoms of something else that is bad.

Have it aligned after the next item you replace. There are some good write ups on here on replacing ball joints. It's not for the "faint of heart" but it can be a DIY job with the right tools and good amount of patience.

 

well i brought my rear drive shaft to a drive shaft shop in Pennsauken NJ. Its was the closest to me and the only one that is a certified Spicer dealer. Anyways three minutes after walking in i was shown the bad news! Apparently the double carbon joint went bad, the rubber that protects the ball and socket was split so all the grease dried up, then the ball and socket started to get ware marks. After it got to a point that it started to wobble it then made my ujoint holders start to egg shape which made the wobble worse. He put the shaft on the balance machine and turned on a lazer pointer and he started the machine. he only got to about 1000rpm and you could see the lazer pointer disappear as the shaft was wobbling on the machine. So i told him fix whatever it needs, SO right now i need the complete double carbon joint in the front replaced and welded on my shaft, then i need three new ujoints, and the rear mount that bolts to the rear axle pinion needs replaced. With all the parts labor and balance its &400 bucks. The guy said its going to be better than stock and I'm wont have any more vibrations. Hopefully when i pick it up at 4pm today and get it bolted in the vibration will be 100% gone, i hope......

 

I've kind of hit a wall trying to figure this out. I now know the shocks are all blown also. I've re-read everyone's posts and don't know why I overlooked sammies suggestion about drive shaft angles. My truck looks like it has a leveling leaf but I'm not 100%. Either way Shimming the carrier isnt going to break my wallet. So, I'm keeping my fingers crossed and will shim the bearing 1/2" increments and see what happens,

 

Logical next step to see if helps. Measure it first and see what it is and post those you want to know where you were before you change anything.

 

ever get it fixed? I had my drive shaft rebuilt, installed it and i have whatever this feeling is from 60-70 mph still! I went to my gear installer Saturday and me and him went over everything in the axles, pinion angle, leaf springs, drive shaft, gears you name it. Took him for a ride and he laughed and said thats road vibrations son! Since mine comes and goes he said its not the truck its the road and the truck is picking it up and it transfers through everything. I went different ways home and sure enough some roads i get this weird vibrations and on others its completely smooth like I'm on a sheet of ice......

 

$3.29 for 2 inches worth of 1/2" washers. I insert 1/4" into each carrier bearing bolt go for a test ride and vibes are 90% gone! I will add a one washer at a time until the vibration is completely gone. Dam best $3.29 ever spent. Well, I thing I'll go spend some more money and buy the shim kit with the bracket. Thanks Sammie and everyone else for the suggestions none went unheard.

Im guessing previous owners never felt the vibes because they used it for towing (as do I) and the weight from the trailer corrected the drive shaft angle. Again I'm the third owner and it looks like there is a leveling kit up front, stock in the rear. I'm glad this is fixed. Now shocks and tires...

 

Well congrats! I know that "happy dance" when you finally solve a long standing irritating vibration!