Well, I have a vibration in my truck and haven't found when it is coming from. Here is what I have done so far.

I have brand new wheels & tires balanced and I have had the driveshaft balanced as well and they have found nothing wrong with anything. I have sat with the truck in Park & in Neutral and slowly went through the rpm up to around 3500 and felt no vibration via the engine. This now leaves me with the transmission and the rear end. I have had no problems with the transmission what so ever with the shifting. I haven't heard any odd noises from the truck. I have talked to the guy that balanced the driveshaft and he is suggesting the bearings in the rear end. There was also mention of the flex plate between the engine & transmission. The transmission has been flushed at 100,000 kms along with new filters. The rear end oil has been changed about a year ago and everything was fine then. The truck has approximately 180,000 kms (approx. 112,000 miles) on it.

Anyone have any suggestions as this is really becoming unbearable as I do alot of long highway driving. I hate vibrations !!!!!!!!!

Have Fun & Keep on Truckin'
Dean

 

I assume the U-joints are new, so my next guess would be wheel bearing.

 

Primetime, thanks for your response. The guys that balance the driveshaft actually takes all of the U-joints out of the shaft and check them over before even putting it on the balancing machine. I had them balance it about a year and a half ago after changing out the OEM U-joints. The shaft became unbalanced as the OEM & replacement U-joints had different weights.
These guys are a performance shop so they don't mess around, they check everything over. Straightness, bent splines, bad hanger bearing, everything. Neal "The HP Freak" sent me to these guys as he has dealt with many performance shop here in Windsor for his own trucks.

Have Fun & Keep on Truckin'
Dean

 

Just a few questions:


When did this start?

Was it gradual, or all at once?

Had you done anything, or added anything to the truck prior to or since this?

Where does it happen (highways, streets, etc.)?

Does it occur consistantly at a specific speed or rpm?

At what point(s) does the vibration occur (start, peak, go away)?

Where do you feel the vibration (seat, steering wheel, shifter, etc.)?

How old are your shocks?

Any suspension upgrades?


Take care
~Chris

 

PKRWUD:

It started about two months ago.

No, it pretty much started all at once.

The last thing that I put on the truck was the tires ... BFGoodrich Radial T/A's - 275/60R15 except the new wheels that we suspected was bent.

The vibration is more pronounced on the highway but can be felt in city driving just not as bad.

No, see above.

I feel it in the seat mostly but there was on a couple of occassions that I felt it through the steering wheel but it went away. I am wondering if it was vibrating sooooooo much that it was going through the steering column.

The shocks have been replaced with OEM shocks from Ford about a year ago. The front bearings were replaced about 80,000 kms ago too. Rear oil has been changed around 80,000 kms ago too.

Everything is stock except the K&N, Exhaust, Superchip, wheels & tires.

Going to the dealership tommorrow (Monday) for oil & lube and NOW the engine isn't running right !!! Man, I guess the old adage of "When it rains, it pours" fits for me right now.

Have Fun & Keep on Truckin'
Dean

 

You said you had the drive shaft balanced over a year ago. Could you have lost a balance weight? Have you had the balance shop look it over again?

I didn't see an absolute response to the question of New u-joints. If they aren't new try checking them again. One may have a broken bearing cup or something.

I may well be wrong but I discount the wheel bearings because you have not mentioned any type of noises. In my experience there will normally make some. (growling, howling, etc) Quick check. After driving a few miles check the temp of the wheel bearings (by hand and BE Careful of any heat) to see if one or more feel abnormally hot compared to the others.

Last thought. Just because the tires are new doesn't mean you couldn't have a bad tire or one that went bad. ie: separated a belt/tread. Even a tire gone bad will sometimes balance on a machine. Do you feel any rocking/swaying at Very low speeds on a Smooth road surface? Has/did the front-end start pulling to either side since/when you noticed the vibration? If so could be your prob. Try rotating your tires and see if the vibration changes or the truck starts pulling one way or the other.

good luck

 

Please clarify for me when it occurs, either at a consistant rpm or speed. For example, while driving, does the vibration always start at about the same vehicle speed (ie: 35mph), regardless of engine rpm (you can drive 35 mph and be anywhere between 4000rpms and 1200 rpms, depending on the gear you're in, so I'm asking does it vibrate at the same speed regardless of engine rpm) or, while driving, does it occur at the same rpms, regardless of speed (does it lessen when you either up shift or down shift, yet maintain the same speed). I understand that while in neutral, rpms had no effect, but I'm trying to understand exactly when it occurs.

Does it continue to worsen as speed or rpms increase, or does it eventually start to go away (ie: vibe starts @ 35mph, is at it's worst @ 65mph, and is almost gone again @ 95mph).

I'm guessing this is only speed sensitive, but need to know.

Also, what happens to the vibration if, when it's bad, you put the transmission into neutral and coasted? In otherwords, is the vibration only created under load, or is load irrelevant?

Take care
~Chris

 

1MoreFord I got the driveshaft back on Thursday from the speed shop and there was nothing wrong with the balancing of the shaft. They take the U-joints all apart when they do this to make sure everything is okay and that the grease is getting into the joints themselves. They couldn't find anything wrong, the only thing is that they can not produce the angle in which the driveshafts sit at to see if that does anything. I was at the dealership today and they said the same thing about the noise for the bearings. I have a Z55 Raven muffler so to hear little noises is very hard unless someone tells me about it or I'm driving beside a building while it is doing it. Which is not very often.

PKRWUD Sorry, if I wasn't clean before. It is hard for me to tell as the roads here in Windsor are very uneven. There are times that I feel the vibration while driving in the city 40 - 60 kms/hr. but it is definately more pronounced at highway speeds. The only really smooth roads that I can really only feel vibration from truck and not from the road itself for long period of time, is on highway roads (401). These roads would be equalivent to your Interstate highways. And I don't wish to do testing while other vehicles are flying by me at over 100 kms/hr. as I am sure that you won't either.

Later today, I will be putting the rear end up on jack stands and I will be bringing it up to highway speeds to see if I still have the vibration then. Hopefully, this will tell me either the front or the rear of the truck needs to be examined more. The service manager did mention that he remembers something being sent out from FOMOCO about the two piece driveshafts having vibration problems but he doesn't remember what it said and what they recommended for a fix. So I will have to do some hunting around unless someone knows what this was and said.

I will report back how my luck has turned out after the jack stand test.

Have Fun & Keep on Truckin'
Dean

 

I found this at AllData:

Article No.
96-12-9



06/03/96
^ NOISE / VIBRATION - "CHATTER" DURING AN EXTENDED PERIOD OF HIGHWAY DRIVING - TRACTION-LOK DIFFERENTIAL - 7.5 AND 8.8 INCH RING GEAR REAR AXLES



^ AXLE - NEW SERVICE KIT AVAILABLE FOR TRACTION-LOK DIFFERENTIAL - 7.5 AND 8.8 INCH RING GEAR



^ AXLE - TRACTION-LOK DIFFERENTIAL - 7.5 AND 8.8 INCH RING GEAR - "CHATTER" NOISE DURING TIGHT TURNS OR TURNS AFTER AN EXTENDED PERIOD OF HIGHWAY DRIVING


FORD:
1989-96 CROWN VICTORIA, MUSTANG, THUNDERBIRD


LINCOLN-MERCURY:
1989-96 COUGAR, GRAND MARQUIS, TOWN CAR


LIGHT TRUCK:
1989-96 AEROSTAR, BRONCO, E-150, RANGER 1989-97 F-150
1991-96 EXPLORER


ISSUE:
A "chatter" noise can be felt and/or heard during an extended period of highway driving. This is due to insufficient specified friction modifier, or over-shimming of the clutch packs within Traction-Lok differentials.


ACTION:
Install revised Clutch Pack Replacement Kit (F5ZZ-4947-BA for 7.5" ring gear and F5AZ-4947-BA for 8.8" ring gear), with improved friction material, in the differential after confirming the "chatter" concern with a road test of the vehicle. Refer to the Instruction Sheet within the kit for details.


NOTE : THE CLUTCH PACK REPLACEMENT KIT INCLUDES SELECTED SHIMS. IT WILL NOT REQUIRE THE ORDERING OF INDIVIDUAL SHIMS BASED UPON TEARDOWN MEASUREMENTS.



REAR AXLE ASSEMBLY IDENTIFICATION

See metal Service Identification tag for rear axle ring gear size and differential type. The identification tag is attached to the rear axle cover by means of a cover bolt.

Take care
~Chris

 

Vibration/Shudder Under Light Acceleration
Article No.
95-23-4



11/20/95
FORD:
1992-95 CROWN VICTORIA
1994-95 MUSTANG, THUNDERBIRD


LINCOLN-MERCURY:
1992-95 GRAND MARQUIS, TOWN CAR
1993-95 MARK VIII
1994-95 COUGAR


LIGHT TRUCK:
1994-95 ECONOLINE, F-150



This TSB article is being republished in its entirety to clarify Issue, Action, Service Procedure, and Operation.
ISSUE:
Torque converter clutch shudder or vibration may occur under light to moderate acceleration above 56 km/h (35 mph) while in 3rd or 4th gear or during 3-4 or 4-3 shifts. This condition may be noticeable on higher mileage vehicles (24,000 km/15,000 mi or more) when the torque converter clutch engages or disengages during light to moderate acceleration.


ACTION:
Perform normal diagnostics (i.e., linkage adjustment fluid level and condition, On-Board diagnostic check). If self test codes are present, service as required. If no DTCs are present, perform the following Service Procedure.



SERVICE PROCEDURE
1. Drain all transmission fluid. Refer to the appropriate Service Manual, Section 07-01 for details. If fluid is burnt or heavily contaminated, repair as required.

2. Remove transmission and replace the torque converter assembly with the correct torque converter. All 1994 F-150's use convertor assembly part number F5AZ-7902-ARM (I.D. #63A & #65A).

3. Remove the transmission pan and clean transmission pan and pan magnet.

4. Inspect transmission pan gasket and filter. Reuse both pan gasket and filter if not damaged.

5. Reinstall filter, pan magnet, and transmission pan with original gasket.

6. Completely clean and flush transmission cooler and cooler lines.

7. Reinstall the transmission assembly.

8. Refill transmission with Mercon(R) Automatic Transmission Fluid (XT-2-QDX). Use only quart containers of Mercon(R) when refilling to ensure proper fluid quality is being used.



PART NUMBER PART NAME
XT-2-QDX Mercon(R) Automatic Transmission Fluid
F5AZ-7902-ARM Torque Converter
F5ZZ-7902-ARM Torque Converter
F4LY-7902-ARM Torque Converter
F4SZ-7902-BRM Torque Converter



Please use the following repair description for each model described in the OPERATION/DESCRIPTION/TIME section of this TSB article:

Perform electronic transmission diagnostics, replace torque converter, drain and fill transmission (including inspection of filter - replace if necessary), flush cooler and lines. Road test vehicle after repairs are complete.
OTHER APPLICABLE ARTICLES: NONE
SUPERSEDES: 94-14-8
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage



OPERATION DESCRIPTION TIME
952304A 1994-95 Econoline 4.6 Hrs.
952304B 1994-95 F-Series 4X2 4.4 Hrs.
952304C 1994-95 F-Series 4X4 6.0 Hrs.
952304D 1994-95 Mustang 3.8L 5.1 Hrs.
952304E 1994-95 Mustang 5.0L 5.3 Hrs.
952304F 1994-95 5.4 Hrs.
Thunderbird/Cougar 4.6L
952304G 1994-95 5.3 Hrs.
Thunderbird/Cougar 3.8L
952304H 1993-95 Mark VIII 5.4 Hrs.
952304I 1992-95 Crown 4.9 Hrs.
Victoria/Grand
Marquis/Town Car


DEALER CODING

CONDITION
BASIC PART NO. CODE
7902 67



OASIS CODES: 501000, 502000, 504000, 510000, 597997, 703000, 703200, 703400


You may even be under warranty. This sounds the most likely, based on your descriptions.

Good luck.

Take care
~Chris

 

PKRWUD: Man, your just full of bad information aren't you. Just kidding, I am getting very pi$$ed with this as I have spent too much time and the money is starting to climb too. Spent $500 on the new wheels, an adjustment for the new tires $230 and who knows what is too come. I appreciate all your and everyone else's help so far. Had to double check the under load / no load question. It does continue to vibrate whether the transmission is in drive or neutral while going down the road. It also does it in the other gears as well except reverse, don't wish to go that fast in reverse. I am having problems with the motor running right, right now and I have had to use 1st and 2nd quite often to get up to highway speed. Please see post in engines !!

When I had the truck up on the wheel stands and the floor jack under the differential. PLEASE BE CAREFUL WHEN DOING THIS !! I noticed that the wheels had a slight bounce to them so I stopped the truck and took the wheels off to eliminate the wheels & tire combination. Brought the truck back up to speed using weight on the accelerator (won't work in cruise, no load to keep constant speed, just revs), I put my hand on the rear-end (no jokes please ) near where the axle comes out, right beside the differential housing and the differential itself. Nothing was hot, just a luke warm feeling. There was no vibration either while my hand was on the axle. This would lead me to believe that the rear-end shoud be fine. HOPEFULLY !! I then proceeded under the truck, I held my hand on the hanger bearing bracket and it was smooth as well, watch the rubber that surrounds the bearing and didn't see any movement. Watched the driveshaft for visible bounce and there was some. I am under the driver's side of the truck, so the driveshaft is turning away from me. I put my flat hand lightly against the shaft while turning to see for bounce and there was some but not a whole lot. Maybe a 1/4" if that. I ran into a fresh stretch of pavement while under construction and yes it does vibrate while at lower speeds. It is not as bad at highway speeds but it is there. I did notice what felt like a wiggle motion at a slower speed but didn't get the speed as there was traffic problems ahead of me.

Have Fun & Keep on Truckin'
Dean

 

You just mentioned noticing a wiggle motion while at low speed. This may be the rocking / swaying I mentioned in my earlier post. Could well be a separated tire belt. You also said the tires had a slight bounce to them. Another indicator. Again let me suggest rotating the tires front to back. Then see if you pick up some vibration in the front end and steering wheel. You may also find the truck wanting to pull right or left. If it does pull swap the front tires side to side and see if it then pulls to the other side. If this happens you definitely have a separation problem. Happened to me with some Michelins that were fine one and not the next. Granted mine had 50K+ miles but it's a frustrating gremlin to chase.

 

Okay then. If the vibration doesn't go away when the tranny is in neutral, then it is not engine/flexplate/torque convertor related. If there wasn't any noticable vibration while the rear end was raised and the tires were removed, that pretty much verifies it being wheel/tire related. 1MoreFord is correct in his description of a radial belt separating, and I'm starting to think he was correct all along. You can't always trust a wheel balancer, or it's operator, to be able to catch all problems. His suggestion to rotate the tires between the front and back is the cheapest way to find out. If you have another set of tires and rims, you could install them and see as well. If you do determine that it's in one of the rear wheel/tire assemblies, take them both to the facility that installed them for you, and tell them you want them replaced. The proper way to do it is to replace both tires, if it ends up being a tire problem, or just replace the defective rim if it's a rim defect. They won't replace both rear tires, but you should. Especially if there is more than 5k miles on them. Tires and brakes should always be serviced and/or replaced in sets. If you do end up with a bad tire, and they will only pay for one replacement, pay for the other yourself, and have the remaining good tire mounted on your spare.

Take care
~Chris

 

PKRWUD, man I hope that you are right. I really didn't wish to have any of that stuff tore apart.

I really wanted to eliminate the wheels and tires but I do have another set at my parent's place but I won't be there until Monday which is the same day I go in for the engine issues. I will switch out the entire set of tires/wheels to see what happens. If it is gone then I throw the front ones on to see and then the back ones. Man, it will be interesting to see what happens at the shop if they are bad. Brand new wheels and I am on the 2nd set of these tires. These ones don't even have 5,000 kms on them. Thank for all of your help guys and I will report back !!

Have Fun & Keep on Truckin'
Dean

 

Well, like I said above. I changed out all four tires to my other set of OEM aluminum wheels with the Michelin's on them. Smooth as glass, there was a slight vibration but that is probably a balancing issue since I originally took these off last April. So I balanced the chromies which is actual the first time since they were installed new on the chrome wheels. So I guess they would have to settle into place since they are going from sitting on a shelf to a 5000 lb. truck. Anyhow, installed the front two and went for a short drive, didn't feel anything. Went back and installed the rear two. I put these back on in the same location that they were from before I put the aluminum ones on. Went for a drive and it was a much smoother ride but I was getting a little vibration but not sure if that was the road or not. I will be able to tell more once I head back to Windsor tonight. I will report, hopefully good news, tomorrow on my findings and see what I will end up doing depending upon the out come.

Have Fun & Keep on Truckin'
Dean