Hello all! New to Excursions and diesels, but I've been reading posts here while a fix up my Ex and the info and members here are quite knowledgeable so here goes...

Very quick background: I'm a pretty handy self taught mechanic. I love anything with a motor, my passion is 70's to 90's BMW's. I've done engine replacements to convertible tops, so I know a little about a lot. Oddly enough, my other "passion" if you call it that is huge SUV's. I recently retired a Yukon XL that I owned since 2004 and drove into the ground, great vehicle! Wanted something different, never owned a diesel and only Ford makes a diesel SUV (most modern at least) so my choice was a little limited.

I picked up a 2004 Limited, 6.0, 4x4 with 205,000 currently. Bought it a year and a half ago with 189,000. Texas truck, bought and drove back to E. TN. This is my 4th vehicle, plus my wife's car. It was intended to be my daily and our traveling rig. We do a fair amount of traveling for daughter's cheerleading and son's wrestling. It was a repo with no history, but is in extremely well maintained cosmetic condition, not so much mechanically. This is ok, I like to work on the mechanics, not upholstery and paint. I have had a lot of fun working on the diesel and learning about them. My "fun" has since ended with a very annoying highway vibration. Here's my dilemma:

I knew when I bought the truck that it needed A LOT of front end work. The drive home was exhausting. 800 miles of vibrating steering wheel, and intense "rattling and knocking" over every bump from Dallas to Knoxville. Still, all good, I knew what I was buying. Once I got it home, I immediately started to restore it to it's former glory. I don't mind spending on this, as I keep my dailies until they die. I want a good as new as possible vehicle. All this time later, I'm so exhausted and disappointed that I have 1 problem with no obvious cause that I cannot figure out...This god-bleeping, bleeping, bleeping vibration at highway speeds! Interstate traveling with the family was half the reason I bought the thing! I've thrown so many parts at it and haven't made it any better. My love of the project is fading and I'm sick of throwing cash at it without knowing it will be fixed. This brings me here...

The list of what I have done is pretty long and very expensive. I will try to remember and list out everything that has been done, but I'm sure I'll forget some things.

Before I even left Dallas:
New el-cheapo tires. The originals were bald as racing slicks. I told the dealer I bought it from I wasn't driving 800 miles on those, so he agreed to put on a set of Thunderer Rangers as part of deal...more on this later.

Engine:
No hg issues. Had a bad oil cooler/EGR causing burping of coolant and terrible deltas(I think that's what you call them) between oil and coolant temps. This was the first thing I tackled. BPD oil cooler relocate, BPD EGR, blue spring kit, problem solved. Engine runs very well. Since then, I had a failed HPOP, replaced with OEM, as well as ICP while I was in there. When summer hit last year, I started getting an intermittent rough idle. Replaced the EGR valve because it looked VERY old and was extremely sticky and crusty from the clogged/failed oil cooler and EGR. I had cleaned it a couple of times, so I just replaced it. Didn't fix it. Ended up being a slipping a/c clutch. I removed 1 spacer, problem solved. Runs like a champ.

Front end:
PITA...I've replaced EVERYTHING...I think, lol. All ball joints (Moog), sway bar links (moog), wheel bearings (moog), Hub and shaft seals etc. Did shocks (Rancho), rotors, pads, and calipers (bone dry slide pins, cheap enough for remans), with Advance Platinum/Gold quality. Steering bars(?) joints were all good, and got alignment.

Drivetrain:
Noticed clunking when stopping/starting and occasionally during shifts. Had driveshaft rebuilt, highspeed balanced, new Moog ujoints. Also replaced shaft seal on rear end. Odd thing on the driveshaft. It is a 1 piece and had the very large rubber inner, metal out doughnut thing around it. I haven't seen one like this before. Driveshaft shop said it was, of all things, a vibration damper and he said he hated them. I recommended removing and fully rebuilding it. Does anyone else have this on their driveshaft? Could this be related? He has a good local reputation and this is all they do, so I trusted him on his recommendation.

Rear end:
Shocks (Rancho), rear rotors, pads and calipers (Same Advance Platinum/Gold, same reason as front), Sway bar links (NAPA Federal Mogul). Fast forward to now, I've got a whine somewhere in the rear and new rear bearings and seals are being delivered today.

Other:
I've flushed/changed every fluid in the truck. Coolant, PS, front and rear axles, brake fluid, trans fluid and toilet paper, oil is Rotella Synthetic, and planning on transfer case one of these days, as I rarely use 4x4.

My problem now:
I have spent a fairly substantial amount for all this stuff over the last year or so, and I'm sure I'm forgetting some things. The entire time I've owned the truck, I have this somewhat intermittent highway vibration. It comes (90%) and goes (10%) of the time in "waves" around 55-85, seems speed related but it doesn't always do it, so diagnosing is a little harder. I've had tires rotated and balanced 4 or 5 times at 3 different places. I've always suspected the tires, but my shops, 1 a local tire center with a good reputation that do all my BMW's, a Firestone auto center my wife used before, and twice at Costco. All of them say the tires are fine, not premium tires, but they balance out fine. The vibration, as best as I can describe it, is felt by the people riding in front, rear and 3rd row, in the butt, armrest, back of seat, steering wheel (not the side to side kind, just a vibration). It feel like the whole truck is buzzing at 85. It does change with speed, at 85 its a fast vibration, at 55-60 it feel almost side to side, but a slower vibration. You can see it in the mirrors, oh crap handles (when comparing to background scenery through the window, and water in the cupholder looks like a scene from Jurassic Park if a heard of T-Rexs where coming. I have tried to rule out the drivetrain, but I'm not sure how to know for sure that it's not an injector "misfire" or the driveshaft? I have a fair amount of side to side play in the steering. On the steering wheel, maybe an inch each way. As stated prior, I still have rear wheel bearings to do so maybe that? Or is it just the stupid tires? If so, how do I know without buying a $1,000 set?

I feel like I'm out of options and the thought of a grand worth of tires that might not fix the problem makes me a little sick mixed with frustration. What am I missing? What should I check? I will take any help and any questions. I'm posting out of desperation, as I've read every single thread I can find here and elsewhere and just can't find anything else to test or check or replace if it's cheap enough. I don't mind the thought of taking it somewhere, but like I said before, I enjoy wrenching and learning, so I'm trying to figure it out on my own (and help from here!) if possible.

So sorry to write a dang book, but I feel the more info the better. Thanks for all the great info I've already found and used to get my Ex 95% where I want it, you guys are great. Hopefully someone with more knowledge and experience with Ex's or SuperDuty's can help me get to the finish line.

 

Welcome to FTE! Sounds like you've put a lot into your rig!

I'd say get your rear bearings replaced and see if that does anything for you. I looked up those tires and while they seem to have good reviews, some say they are loud and wobble a bit. As far as the driveshaft, I have the large donut on mine and at 293K, no issues. That doesn't mean you don't have a problem with yours, but I don't see it as a detriment. If the shop rebuilt and balanced the shaft, should be no problems either way. Do you have a way to monitor the parameters on the 6.0? The only way you could rule out your injector idea would be to see if it's throwing a contribution balance code or get Forscan and watch the contribution real time. Having said all that, I'm still leaning on the tires being your issue. Unfortunately, tires are expensive and that's just the way it is. I'd recommend a set of Michelin LTX MS 2's. I have a set on mine and they are super quiet, tow nice, wear REALLY well (I got 100K out of a set on a Tahoe), and as tires go aren't super expensive.

 

Keep in mind (a) I’m no mechanic, and (b) maybe I missed it in your post, but one thing to check are your front hubs/transfer case.

Are your front hubs (or maybe just one) locked while in 2wd? If so, that might be the cause.

Have you engaged the 4wd to see if it works (engages and disengages completely)? Wondering if possibly the 4wd transfer case is engaged, but the hubs are not locked (so the front axle is powered and turning, but no power is transferred to the wheels so there’s no 4wd binding)

 

When I was diagnosing the clunking at stop/start, I removed the front driveshaft completely to see if it was part of this problem...4x4 system is also where my experience is limited, so pardon my ignorance. By removing the driveshaft, I can rule out any issues with it being balanced or not, or bad ujoints on it. As I understand, it would not be moving unless 4x4 is engaged correct? My 4x4 does work. In fact, it failed shortly after I bought the truck. Got stuck in my brother's back yard with a trailer full of firewood and had to manually lock the hubs to get out. It ended up being simple, some kind of vacuum switch had failed. Replaced that too, lol, and it works fine, engages and disengages correctly. I have verified this when I did the front wheel bearings 2 or 3 months ago. Checked them before and after, they engage and disengage on command. Is there something else other than what I have tested? Again, not super good on 4x4 systems.

 

Totally agree on the wheel bearings, it was cheap, repair doesn't seem too complicated. However, I'm doubting it since I feel the vibrations in the entire cab, steering wheel and all. Is this thinking incorrect?

I totally agree with you on the tires, I'm very suspect. I read the exact same reviews you did and was surprised at the positive reviews. I'm trying to rule out other things, since they are super quiet, and heck, its a brand new set of tires that 3 different shops say balance out fine. I even mentioned that I suspected the tires to see what the shops would say and no one said to replace them, which surprised me.

I tried searching for the doughnut thing on just a google search and it didn't seem like many, if any, had this. I assume this is a factory thing and I'm glad you have one so I know it's "normal" and some aftermarket fix I regret removing. There was so much wrong when I got it, I hated doing too much at once for fear of making the vibration worse. I have also rotated the driveshaft in relation to the transmission 3 different times to make sure it wasn't out of balance with the engine and trans, no change. I do trust the driveshaft shop, but I had also thought about taking it back for them to check? Any opinion?

I have a ScanGaugeII but I've tried playing with the "misfire" and contribution stuff but people say not all programming feature work on all trucks, which is the case on mine. Nothing related to injectors registers a value output. I also read that not all years or "flashes" will show a CEL for a bad injector. Is this correct? I would think, like a gas vehicle, a "misfire" would register a CEL?

 

If this posts twice, sorry, I got a message about my reply not being posted until it's reviewed my moderator? Strange...

I have removed the front driveshaft completely to rule it out. Drove for a week or so with it off, no change. I had lost 4x4 in my brother's back yard last winter actually. Got stuck with a trailer load of firewood, had to manually lock the hubs to get out. It ended up being the vacuum switch, easy fix, works perfect. I verified this when I did the front wheel hubs a few months ago. The lock and unlock on command. Is this a good way to test, or am I missing another test? I'm not as good with 4x4 systems as I am with other things, never worked on one, but all my trucks in the past were 4x4. Any additional advice or guidance is appreciated due to my lack of knowledge.

 

Welcome to the FTE.

2 things come to my non-mechanical, trainee mind

1. Have you tried a different set of wheels and tires? Are you sure that your wheels are not damaged in any way? I have not heard of this brand of tires, so not sure how well they balance. Also, are they rated for this super heady duty vehicle?
2. I read your list of new parts for the front end, but did not see that you replaced the front track bar. You may want to keep an eye on that too.

 

If its lifted, I'd suspect bearings in the transfer case causing the vibration. Easy way to check: block the front wheels, disconnect the rear driveshaft at the transfer case, put it in DRIVE and slowly increase to 3500-4000rpm. If the Tcase is the cause of the vibration at highway speeds, you'll feel it in the cab with this procedure. I recently had a gear swap (3.73 to 4.30) on my Ex and chewed out the mechanic for doing something wrong after my first test drive. Well, he politely informed me of the real issue and threw it up on the rack and proved it. I'm now shopping for a replacement Tcase.....

 

Had a similar vibration. Intermittent at highway speeds. Finally traced it down to the parking/emergency brake shoes.

 

Can you say more about that?

 

The parking brakes just needed proper maintenance. Found them very rusty with broken springs and disintegrated brake shoes. New parts and high temp brake grease solved the vibration issue for our Ex.

 

Thanks, that's one of the few areas I haven't gone into. Ok I'm goin in.

 

Rear bearings are pretty easy, and even easier if you buy the special socket. I'm not sure they'd be causing the vibration either. I will say that will 293K on the clock, mine were like new still. I'm not sure what years will throw a CEL for a bad injector. I had contribution balance codes on mine with no CEL.

 

1. That is the most obvious, and easy check, but that is also where I'm out of luck. Rims are good, not cracked or warped. No change in vibration after 2 or 3 rotations and balances. No one, so far, in my circle of friends has a vehicle with the correct wheels and tires to fit. I'm the only one with a SuperDuty. Anyone with better knowledge on this know of another make and model with wheels and tires that would fit?

2. The trackbar is the only thing I haven't replaced, but also the only thing that was in good order. It could still be suspect, but feels tight, good seals, and the alignment shop agreed it was fine.

 

Hey, now there's something I have not tried! I will do this ASAP, hopefully this weekend! I will post back results, and thank you for the suggestion.

Not lifted, factory wheels, no tunes. I did go with a slightly large tire, 285 vs 265, but only to fill the wheel well a little better.