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Feb 10, 2005 | 04:11 PM

chmath

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From: jax. florida

Unknown vibrations

I have a 1990 F150 4x2 4.9cl 300.

I have a vibration problem while at any speed and increases when towing....
I have shifted it into nuetral and with the o/d on and off the vibration stay's the same....I have already thought of tourqe shudder but it does it in nuetral also and under any load condition...It does it if i push on the gas or let my foot off of it.

I have replaced the ujoints,had the Drive shaft balanced, Tire's rotated and road force balanced, New brakes and rotors, calipers, wheel bearings all of the back breaks have been replaced also....I have checked all of the motor mounts and trans. mount....

I have checked the codes and the only one that I get is 11...
I have been searching all over the fourum and have read at alot of post and still have no idea where to go next or what to check.

Any Ideas?????

Last edited by chmath; Feb 10, 2005 at 04:13 PM. Reason: adding

Feb 10, 2005 | 04:32 PM

92supercab

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Joined: Feb 2004

Posts: 155

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From: Alaska

What about an alignment or bad tires?

Feb 10, 2005 | 04:53 PM

chmath

Thread Starter

Senior User

Joined: Nov 2004

Posts: 165

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From: jax. florida

All of the tire's are new and have been road force balanced ...had the alignment check twice ..... No bent rims had those checked also....

Feb 11, 2005 | 03:59 PM

chmath

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Senior User

Joined: Nov 2004

Posts: 165

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From: jax. florida

Still have no idea where to look next ......

The tire place thought it might be the tire's that I bought so I brought it in and changed out all four and road balanced them again and it still rides the same....I haven't been able to tow my trailer due to fear of unknown vibrations....I had a trans. shop take a look and the also agree that all is fine there....

Help .....It is driving me nuts......

Feb 11, 2005 | 08:35 PM

dybeepvw

Mountain Pass

Joined: Sep 2004

Posts: 249

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From: AZ

How about your harmonic balancer or pulley's on engine.

Feb 12, 2005 | 10:25 PM

Bueller

Tuned

Joined: Aug 2003

Posts: 386

Likes: 28

From: Garnett, KS

I have pretty much the same thing happening in my 84 w/ a TOD 4 speed F-150. You can barely notice it at lower speeds, until you get to 45mph. It starts getting bad after about 60mph and REALLY rumbles the faster you go. Is this what you're experiencing? I went through pretty much the same motions. I'm guessing its in the rear axle; either a pinion bearing, or axle bearing. Haven't been able to examine closely yet. I saw another post here somewhere, where a guy had carrier bolts come loose and it was acting kind of like that.....let me know if you find it, and I'll do the same....

Frank

Feb 12, 2005 | 10:40 PM

chmath

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Joined: Nov 2004

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From: jax. florida

I have a strong fealing that it may be the rear leaf springs.....I was telling a guy at Autozone about the problems I was having and he told me he went thru the same thing on his 1992 ford f150 and it ended up being worn out leaf springs.

I bought a set of leaf spring helpers for $24.99 and put them on and it took almost all of the vibration out....I'm going monday to order a new set of leaf springs and switch them out and hopefully that will solve the proble all of the way...

I'll let everyone know what the outcome is at that time...From what he said if the leafsprings are worn out that it will cause a vibration and not keep enough
downforce on the rear end.....If that doesn't fix the problem.....Truck will be going into the shop to have a complete evaluation.....

And if that doesn't work.....The final solution is a couple of gallons of gas, bag of pocorn and a few Beers.......And one huge bonfire....LOL......