Hopefully a fellow F150er has some insight into this problem. My 1998 F150 SC 2WD vibrates at 60-65 MPH. It doesn't seem to be a front end shake. You can feel it in the whole truck and see it in the mirrors! The truck has done this since I have owned it which is about 25k miles. New tires were installed and balanced a month ago. Any help is much appreciated.
Dan

 

It's possible that you driveshaft could be out of balance. If thats the case it might wear u-joints pretty fast. Another thing to check would be to jack the truck up and make sure all your wheel bearings and balljoints are tight.

-Jon

 

If the problem was not there right after the tire change you
may have the balance checked again, My truck did this awhile
after new tires and turned out some of the weights had fell off.
It rides like new again now!

 

It could also be bad lower ball joints. Mine were bad & when I replaced them it seemed to clear up my high speed vibration.

 

dang, Check and see if transmission tail shaft housing seal is leaking. If it is the bushing in the tailshaft housing is worn and the driveshaft may be "flexing"causing your viberation. If you have to replace the bushing you don't have to buy the extension housing (tailshaft housing) with the bushing in it. Go to a transmission shop and buy the bushing,rear seal and housing gasket. It's 1/4 the price of a extension housing from Ford. Ford has a bulletin on this ( Article # 01-9-3). If you want it i'll send it to you. Jack

 

Jack,

I would sure like to see that bulletin. If you could send it my way I'd appreciate it.
unisteel_tom@hotmail.com

 

Tom, I tried sending bulletin but it keeps comming back. It said it"s over your quota. I resent half of it and i'll try to attach it here. If you want the other half i'll send it later.

 

Thanks Jack.

I got the first half OK. That gives me an idea of what to look for. Since my truck is a 2001 it looks like it's not involved but I'm still going to crawl under it and check things out.

 

My truck starts to vibrate at 50mph and doesn't stop. I had the tires ballanced and checked for out-of-round last week and that didn't do anything at all for the vibration.
On Friday I checked the rear differential and changed the fluid. While the rear wheels were off the gound, I turned the wheels by hand and could hear squeak coming from the rear of the transmission or front of the driveshaft each time the driveshaft rotated.
Part of the TSB calls for replacing the driveshaft with one having a 5 inch diameter. The procedure doesn't seem as though it would require much time but if Ford expects me to pay for a new driveshaft when they put the wrong one on to begin with, I'm not going to walk away quietly.
I plan on contacting the dealer today but don't know when I'll have time to get this looked at.

Driveline/Extension Housing - Vibration/Leaks
Article No.
01-9-3

05/14/01

^ VIBRATION - FROM DRIVELINE - 4X2 VEHICLES
WITH 4R70W AND 139 INCH WHEELBASE

^ TRANSMISSION - 4R7OW - FLUID LEAK FROM
EXTENSION HOUSING SEAL - 4X2 VEHICLES WITH
139 INCH WHEELBASE

FORD:
1997-2000 F-150, F-250 LD

This article is being republished to update the model year coverage and to update the part application.

ISSUE
A driveline vibration and/or a transmission fluid leak from the extension housing seal area may occur on some vehicles. This may be caused by the extension housing bushing or seal walking/spinning out due to excess driveshaft flexing during extended high speed operation.

ACTION
Inspect the extension housing bushing and seal. If the extension bushing/seal is spun and/or walked out, replace the extension housing assembly and gasket with new service parts, and replace the driveshaft with a revised 127 mm (5") diameter driveshaft. In addition, some vehicles will require the balance marks on the driveshaft, output shaft, and rear axle flange to be aligned so a repeat condition will not occur. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

1. Raise the vehicle on a hoist and inspect the transmission extension housing bushing and seal for damage. In addition, inspect the driveshaft diameter. The revised driveshaft has a 127 mm (5") diameter and the old part has a 114 mm (4.5") diameter.

2. If the extension housing bushing or seal is damaged, remove the driveshaft and transmission extension housing per the appropriate year Workshop Manual, Section 307-01. Install a new Extension Housing Assembly (F3LY-7A039-A), and a new Extension Housing Gasket (F6AZ-7086-A). Verify transmission fluid level.

3. If the vehicle is equipped with the 114 mm (4.5") aluminum driveshaft, replace the driveshaft with the revised 127 mm (5") Driveshaft (see parts list for application).




OTHER APPLICABLE ARTICLES: NONE


SUPERSEDES: 99-26-2
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME

010903A Replace Extension 1.6 Hrs.
Housing Assembly;
Driveshaft When Required
(Includes Inspection Time)

DEALER CODING
CONDITION
BASIC PART NO. CODE
4602 42

OASIS CODES: 501000, 502000, 503000, 504000, 510000, 703000, 703200, 703300, 703400

 

Sounds like this could be the problem. I'll have it looked at right away. Thanks to everyone for posting. Especially AJRagno for posting the TSB.