02 Sport 4WD Vibration Problem - Need Help

[Wharf-Creek]

Hey Group,

I just acquired an '02 4WD Sport, 125K on the clock. Overall in good shape, had not been driven in a year. In order to get back to road-worthy I had to replace a front hub-bearing, brakes ft. and rr, a front sway bar link, a battery, and some wiper blades. That got me through Maryland State Inspection. Now I'm battling with a non-inspection related problem that might just cause me and this car to part our ways. Truck has what I'd call an unacceptable vibration that starts at about 38 mph, at 40 it's really annoying, at 45 to 50 it goes away, and comes back again at about 65.....is bad at 70, and at 75 to 80 it's pretty much gone again. I've had tires (michelins) balanced 3 times, and I've pulled both drive shafts and inspected the joints....2 standard U-joints on the rear shaft, and a conventional U-joint on the front of the front shaft, and a CV joint on the T-Case end of the front shaft. All joints seem fine. Further, I see no thrown weights or anything on the drive shafts....either of 'em. This 'feels' like a front shaft out of balance. The frequence at 40 MPH is enough to make most of the interior panels vibrate and rattle....and unlike tires...it's a 'higher frequency' of vibration. I've got over 34 years experience with MOPAR products, and this is my first Ford since my '64 Mustang. In those years with Chrysler, I learned that there ARE problems that are unique to the product. Not necessarily 'engineered' into the vehicles, but something that only another MOPAR tech might know. So....I'm hoping that someone on this forum can help steer me in the right direction. I'm not sure where to go next. I did drive this truck with the Front Drive Shaft removed...but it was in a snow storm and I actually ended up in the passenger seat for this test drive. I thought I still felt the vibration, so we put the front shaft back in, which is where it is now. Also, I should mention that my 4WD is currently dysfunctional....but I have a new 3WDCM on order.....should arrive by the end of the week. Anyway, my name is Tom, and my regular email address is Wharf_Creek at Hotmail dot com. I assume this forum, like others, would underline my email address (or any URL) which obscures the underscore between Wharf and Creek......so please forgive my unconventional placement. Again, thanks for any help, and I hope I hear from someone soon. Oh....I do NOT believe this to be a tire flat-spot problem, although the tires did sit for a year. I've pumped 'em up to about 45 pounds, driven it for about 100 miles, then dropped the pressure back to about 34 PSI, which is where they are now. OK....many thanks...and Happy Holidays! TSD

 

[swetrid]

In the shop we would use an EVA (electronic vibration analyzer) to give us an idea if its tires driveline etc. Ford has a long and nasty tsb for vibration above 45 mph.

 

[Wharf-Creek]

I called my local Ford dealer yesterday. Left a message for the Service Manager at about noon. Finally got called back today at about 3 pm. All he wanted to know was if I had any intentions of making an appointment. Didn't seem concerned at all about my problem, just about getting me in so he could book $100 of check-out time. I asked about any TSBs for the truck at which he responded that he couldn't help since I didn't have my VIN....which I immediately provided. He reluctantly searched....or so he said....and came up empty handed. Funny....you mention a long and nasty one for Vibrations over 45.....and this guy said there was nothing for vibrations at all! I guess he didn't care too much about me. I hate to say it......but 'typical' of Franchise Service Departments when it comes to helping the DIY'er. Anyway....my vibration is absolutely at it's worst at 40 MPH on smooth pavement. It starts at about 35....hits it's peak at about 40...then tapers off after that...and is essentially gone at 50. However, at about 65 it starts to raise it's ugly head again....and at 70 it's back to full force, and then tapers off after that....and at 80.....it's pretty smooth. So.....the unit does still have the front drive shaft installed....and I'm going to go out tomorrow if the weather permits and see if I can't remove it and then drive it a bit more. I'd LOVE to see the problem go away from doing that. At least I'd have a few options to work with at that point. Anyway...thanks for responding, and I hope I get a few more 'hits' from folks who have some additional comments or ideas. Happy Holidays!! Tom D.

 

[swetrid]

Ford has tsb 00-14-03 but doesnt include 2002 Sport, my bad.
Printable View (206 KB)
TSB
00-14-3 VIBRATION - SHAKE - RESONANCE NOISE - SPEEDS ABOVE 72 KM/H (45 MPH)

Publication Date: JUNE 29, 2000

FORD: 1999-2001 EXPLORER


ISSUE:
A vibration at speeds above 72 km/h (45 mph) may occur on some vehicles. This may be due to an imbalance in one or more of the driveline components which results in a resonance that produces a noticeable vibration usually in the seat or steering column.

ACTION:
Refer to the following Drive Diagnostic Procedure and System Balancing Procedures. Follow the initial drive diagnostic and note any changes after each drive.

DRIVE DIAGNOSTIC PROCEDURE

Ask questions of the customer and find out when the vibration occurs. Base diagnostic work on customer usage of vehicle (such as gear, speed, load, and towing.) It is also best to ride with the customer and make sure you know exactly what the concern is. Also, use an Electronic Vibration Analyzer (EVA) if available at seat track, rear pinion, and front differential cover to find the source of the concern.
Start the vehicle. Does a vibration exist when you perform neutral rpm engine run-ups? If it does, review engine driven components, fan, and transmission torque converter for possible imbalances. Repair these concerns first and retest.
Before driving the vehicle, review the tires for signs of wheel misalignment or worn suspension parts such as shock absorbers, ball joints, and bushings. (Reference Section 100-04 in the appropriate model year Workshop Manual.) Repair and/or replace worn parts. Drive vehicle to see if concern is corrected.
Document the operating conditions required to duplicate the customer's concern including: Coast/Cruise, AUTO/4H/4L, Acceleration/Deceleration.
Document the vehicle speed, engine rpm, and gear at which the concern is duplicated. If an EVA is available, document the frequency (hertz) and amplitude of the vibration.
On 4.0L 4X4 models while at a stop, place the transmission in Neutral. Switch from 4AUTO to 4L. Place the vehicle in Drive and drive a short distance (6-9 meters/20-30 feet). Put the transmission back in Neutral and switch back to 4AUTO. Re-drive the vehicle at highway speed. If the vibration goes away or gets worse, contact Borg-Warner at 1-765-286-6569.
Inspect transmission mount to see if it is twisted or mispositioned. Look for strap grounding out against the mount. If this is occurring, loosen the mount bolts, neutralize the mount position, and allow the strap to straighten out. Tighten the nuts and bolts to 87-110 N-m (64-81 lb-ft) in torque stages. Retest the vehicle.
If an EVA is available, isolate the vibration to a probable rotating component. Using the EVA, match the monitored frequency to a possible rotating component using the engine speed or vehicle speed method as described in Section 3-30 of the NVH Student Reference Book supplied with the Ford NVH class or Page 0-9 of the SPX Kent-Moore Instruction Manual that comes with the EVA test equipment.
After recording all information, review the following Symptom Chart first to avoid the replacement of good parts.
SYMPTOM CHART

CONCERN POSSIBLE SOURCE ACTION
Shimmy Tire Go to Pinpoint Test A1
Steering
Axle Flange
Alignment
Rear Suspension Sag

Body Boom Driveline Go to Pinpoint Test B1
Driveshafts
Body Resonance
Exhaust System

Vehicle Speed Dependent Vibration Tire/Wheel Go to Pinpoint Test B1
Driveshaft
Axle
Transfer Case

Engine Speed Dependent Engine Go to Pinpoint Step C1
Drive Accessories
FESM Mounts
Body Mounts
Engine Mounts
Exhaust System


SYSTEM BALANCING USING AN EVA

The following procedure is a basic outline on how to system balance the vehicle using various methods available. For more detailed information, refer to Section 100-04 of the Workshop Manual or the manual provided with your Electronic Vibration Analyzer (EVA).

Before starting, be sure that the runout of the driveline components is within specification. This specification can be found in the Workshop Manual or in this Diagnostic Procedure. If components are found to be good, proceed with strobe balancing using the EVA.

Number the ends of the driveshaft by the transmission and the axle pinion 1 through 4, putting a number every 90 degrees. Then place an accelerometer at each end of the driveshaft.
Mount the accelerometer on the bottom of the rear axle differential or the transmission extension housing. Be sure to position the sensor as close to the driveshaft as possible, assuring that the UP side of the accelerometer is up and the sensor is horizontal.
Have the vehicle positioned on a hoist and set up on jack stands to level the vehicle with the wheels removed.
NOTE: BEFORE STARTING TO STROBE THE VEHICLE, BE SURE ALL LOOSE ARTICLES ARE CLEAR OF MOVING COMPONENTS. NEVER TOUCH MOVING PARTS WITH YOUR HANDS.



Turn off all accessories and have an associate start the engine. Place the engine in gear and accelerate the vehicle to speed where the vibration occurs.
With an inductive timing light clipped to the trigger wire of the EVA and the accelerometer plugged into input A, be sure both the EVA and timing light have a 12 volt source.
Verify that the predominant frequency displayed on the EVA matches the frequency of the original reading taken with the EVA. Press "STROBE" key on the EVA pad. The EVA will display a series of questions in order to select the correct filter. Press "YES" to select the correct filter. Be sure that the frequency is in the middle of the filter range. Use full range only if these ranges do not give the desired results.
The display on the EVA shows the test frequency, the amplitude, and the filter range. The driveline is balanced when the strobe amp is between 0-4, or when the flashing strobe becomes erratic or ceases.
Point the timing light at the driveshaft. The strobe will appear to freeze the driveshaft. Note at which of the numbered marks it is on or closest to.

OTHER APPLICABLE ARTICLES:
NONE

WARRANTY STATUS:
Information Only

OASIS CODES:
303000, 304000, 702000, 702300, 703000, 703200, 703300




Figure 1 - Article 00-14-3




Figure 2 - Article 00-14-3




Figure 3 - Article 00-14-3




Figure 4 - Article 00-14-3




Figure 5 - Article 00-14-3




Figure 6 - Article 00-14-3




Figure 7 - Article 00-14-3


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