Attention (Y2K 7700 4 x 4). I had posted about a 6 month attempt to stop a vibration that came at 64 MPH. Dealer tried a variety of things. Nothing worked. I had mentioned to the Ford service mgr about a post on this forum by Y2K 7700 4x4. This had to do with the exhaust line not totally secure. Do something to put tension on it, clamp it, weight it, things of that nature. Thursday I took it in while a Ford field rep. was at the dealer. They kept it for 2 days. I picked it up this am and lo and behold...that was the problem. They weighted and put clamps and tied it to frame more securely.

Having said all this, I feel totally relieved. Will it hold up? Gotta think positive that it will. Naturally, one worries that it could have been an internal problem with the engine.

Thanks again, Y2K 7700 4x4.

Lloyd Williams
Bakersfield, Ca.

 

Dear Lloyd:

You've made my day!

Vibration is really wierd, isn't it? There are so many 'tuning-forks' in a vehicle that it's amazing that they don't shake themselves apart.

I've done some lab work on changing the natural frequency on many wierd items that go on heavy truck axles and brakes; and have seen some strange things go away (actually, they never really go away, they just get moved to another frequency -- one hopefully that is not noticed or bothersome) by lengthening/shortening things.

Chalk this one up to 'wierd science', and things are rarely as severe as they seem.

Thanks for the post,



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Y2K™

XLT SC SB 5.4L E4x4 AW-Disc, 3.73LS, Skid, 7700# HD Towing, Chrome LT-245, Steps, Captain's, 6CD, Tonneau, keyless, Toreador Red, called "Nick"

 

What kind of vibration was this???

Was it a low booming type of noise? Could you please decribe it??

Thanks---Bob

 

The thread went like this:

By Lloyd: posted 04-14-2000 07:53 PM
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My 2000 F-150 V-8 5.4 has 6000 miles on it. At 2000 rpm (or traveling 64 MPH in overdrive), a vibration comes in. As the rpm increases, the vibration lessens.
When parked and in neutral, revving the engine up to 2000 RPM produces the same vibration, so I think that would eliminate any wheel, front end, drive train, rear-end, etc.

I've gone to the dealer and they don't know much about it. I am really concerned about this. Is there anyone out there who may have a clue? Or anyone with the same problem who found a fix?

Any help would be GREATLY appreciated.
Thanx.

My reply was:

posted 04-14-2000 10:18 PM
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Find something heavy that you can strap/clamp/tie or otherwise hang on to your exhaust system. See if you eliminate or move the vibration to a different speed.
If that doesn't work try the same at the end of your transmission output shaft.

Ford doesn't hang that big chunk of iron off of the tailpipe/transmission because they have extra steel laying around the shop.

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Y2K™

 

I had pretty much the same funny vibration problem on my '99 F 150 extended cab with V-6 and manual tranny. Got a funny vibration at about 1000 rpm.
On a quiet sunday morning I went down to the local Ford dealer and took a peak at some newer F 150's and noticed a rather funny looking short cylinder clamped just before the front end of the mufflers.
Someone informed they kinda felt like they were full of sand when shifted around.
I went to the hardware store, purchased a 1 ft or so long piece of larged threaded pipe and two end caps. I filled the tube full of BB's, and put the end caps on snugly.
After attaching the tube to my exhaust pipe, the vibration is almost non-existent.
Seems the rather long length of the muffler and exhaust system was resonant and the tube functions as a damper.
Oh yeah...I have the stock muffler.

 

Neat idea! I'll put it in my bag-o-tricks.

Tks,

Jim