Well, my vibration issues amplified recently when I stepped up to 4.56s gears on the stock tires. The increse in driveshaft RPM caused a vibration that was very annoying from 70-80 mph (which would occur around 85-95 mph stock), and my 55-65 mph typical vibration when stock was now moved down to around 45-50 mph.

From my experience with mustangs, this vibration felt 100% to be caused from the heavy stock driveshaft. Well....I went and had a custom driveshaft made. The tranny yoke and pinion flange yoke are the same as the older 4R70Ws and 9.75s in the 97+ F-150, it's just the length that's different. After speaking with the driveshaft place about my particular set up, they suggested a carbon fiber over aluminum. The aluminum would have to be 4", and with the 4.56s spinning the shaft so fast on the highway, it would likely still vibrate a little. The carbon fiber shaft was NOT cheap, but only weighed 14.5 lbs compared to the stock 30 lbs!! Install was a snap....easier than installing a catback exhaust.

Now that it's in, I have ZERO vibrations. The truck is smoother than it was the day I bought it. So, the vibration problem on our trucks is NOT ring and pinion or tire related...it's the 30 lb tank of a stock driveshaft being improperly balanced, or just being too much spinning mass. The shaft is nearly 70" long!

I have worked out deal with my main distributor (I run a small import parts business from home) to give me a decent deal if I buy quantities. Now, on stock geared trucks, the aluminum shaft would likely provide the same results since the shaft is spinning a good bit slower. I don't know the price on them....maybe $450? If I can get 5 or more buyers on the carbon fiber, I can get the price down to $795 each. This is a small fortune, but to me it was worth it to rid the truck of the dreaded vibe. ***NOTE**** I am not trying to sell anything as an unauthorized vendor. I sell import performance parts, NOT F-150 truck parts. I just happen to have the ability to get these driveshafts at a discount over retail, especially in quantities. I am not making money on this offer. I am doing it for the benefit of other F-150 owners. Also, this custom made shaft was done on my 4WD Supercab, 6.5 ft bed truck. Lenghts will vary significantly between all the different configurations. I can direct you on how to measure correctly to ensure the correct shaft is built. I am also only ASSUMING the aluminum will get rid of the vibe on stock geared trucks. I really don't know for sure. Anyway, I just thought I'd share (what I feel is) the greatest piece of info to ever exist for our new trucks.

 

You da man!! Fortunately I don't have the vibe (Knocking on wood)

 

I noticed that there is a msg on my drive shaft. DO NOT DROP. I wonder how many vibrators had their drive shafts dropped???????

 

Hey Robert04...really interesting info!!

To confirm it, send your old drive shaft to jperea. Let him install it and see if HE gets the vibe!!

JUST KIDDING...and DON'T send it to ME...I don't have the vibe either!

It sure would be nice if you hit the nail on the head!! You may be onto something!

 

Hahaha...I got a laugh out of that too! Does yours also say, DISCARD IF DROPPED. You two must be the only ones who had a properly handled driveshaft Although I'm not too sure how much could get thrown out of whack on a driveshaft by dropping it, unless it fell a good distance, but an interesting thought. I'm very disappointed with Ford for going to steel on the 04s. The damn thing weighs enough as it is...why add an extra 10 lbs and more vibration to the smoothest and quietest truck in production?

BTW, Nissan is about half as cheap as Ford. They use a two peice driveshaft and put rear aluminum shafts on the 4WDs, but 2WDs still have steel in both sections. The rear shaft on the 4WD Titan has to be over 4" in diameter....the thing is HUGE. Also, the Titan also faces some vibes from the stock driveshaft. My friend's 2WD XE King Cab reportably has a vibe at highway speeds. I think any boxed steel frame truck with a long steel driveshaft will transmit vibrations through the truck, athough my wife's 04 Explorer has no vibrations at all (even with a steel driveshaft)...BUT it's a LOT shorter.

 

My first truck in '85 had a HORRIBLE vibration when I picked it up and rushed to work. When I got there, put it up on a lift and saw the driveshaft was dinged. Turns out that the truck fell off the transporter ramps as it was getting offloaded at the dealer! Of course, nobody noticed ANYTHING until I took delivery and drove it on the hiway to work.

Got the driveshaft replaced that night, no further problems!

 

You are a continuing gold mine of information, Robert. My thanks and from the group as well I'm sure. Don't have the vibes (6,300 miles now) but should some show up, yours will be one more solution (and maybe the first) to try. BTW I disagree with you on the cost of this fix. Some in here spend far more on cosmetics than that. If this is the true solution, then this cost is peanuts compared to the benefits.

 

Ahhh what the hell... I'll install it and post results.. Just pay the shipping.. Seriously, though, I think you're on to something. I saw this article....

http://www.epcorp.com/NR/rdonlyres/...FORDRELEASE.pdf

 

And this one too..

http://www.auto-innovations.com/actu-news/020.html

 

Sorry try this one....

http://www.epcorp.com/NR/rdonlyres/A...ORDRELEASE.pdf

 

Robert- If you were inclined to throw away the dollars on a driveshaft you aren't going to use, you could take it to Advance Driveline and have them balance the old driveshaft so you could see just how far out it is. It's only $45 for the balancing according to my quote from them.
BTW, let me know about those used gears.

 

Well, the problem is not the balancing....it's the mass in general...at least with my 4.56s. The driveshaft shop specifically did not want to do even the aluminum shaft for my truck because it would vibrate when spun over 4,000 RPM, which would happen just over 80 mph for me (not engine RPM, driveshaft RPM, or 3rd gear RPM). SO, even a perfectly balanced stock shaft would not have gotten rid of my vibrations. I wish the aluminum would have been the definite choice, since I'd have nearly $400 more in my pocket right now!

 

I've been keeping track of the vibration threads in here for quite awhile now and probably have read most of them even going back a couple years. One trend I noticed was the 3.75 gears had way more mentions of troubles than those with the 3.55 gears. So when you stepped up to 4.56 that may be another "clue". Also I said in a different vibration thread most people won't see it past 10,000 miles if they don't have it already. Well on another thread I saw where one guy's vibration problems started after 28,000 miles. My suggestion to those with the vibration problems is this: use this forum to your advantage. Try the search feature and take an afternoon to read all the vibration threads. At that point you can make a spreadsheet detailing the specs of the trucks that have the problems ie 4x4 vs 4x2 or XLT vs Lariat). Also you can list all the "solutions" that have been tried. Seems like some of the solutions came in the tire area, some in suspension, some in the frame, and now the driveshaft. Well that is my suggestion and even though I don't have the vibration problem (knock on wood) I wish I had the time to do this. But if I did have the problem I guarantee I'd spend the time to do it.

 

Reading that FORD release about installing the vibration dampeners it sounds like they know they had a problem back in 93 and that the dampeners were be added to fix it

Either they didn't work or some of them are not up to spec

 

I'm not sure I'm buying this driveshaft problem unless it specific to the driveshaft builder Ford is using. There's an awlful lot of allot longer driveshafts than what a Scab takes out there spinning just fine. If balancing them isn't the problem and critical mass problem is then what you would be feeling is a driveshaft whip.


Well anyway my Lariat is smooth as glass up to 90mph, but it should be interesting to see what Ford's cure is on Dec 8...? Maybe we are all getting new driveshafts.....if we let them change them..