'98 4wd in Auto mode constantly engages/disengages when accelerating

[Robert]

I have disconnected my transfer case shift solenoid, thereby forcing it into 2WD. I will report back after a couple of tanks on my mileage results. I still don't think it will have any affect since only 4% torque goes to the front wheels unless they slip. Here in Phoenix, that doesn't happen too often unles I leave the pavement.

 

[KMac]

Jon,

I would appreciate knowing what TSB that is. My '98 does the exact same thing and I want to get it fixed.

Thanks.

 

[Kinnish]

Tonite I put back on my stock rims and wranglet TA's or whatever and took off my 31BFG with MT Classic II's and wow, the transfer case engaging isn't as noisy engaging with Control-Crap. I'm with all of you I want to get it fixed. I'm guessing ford can do something major about this but my next thought was to get rid of that transfer case all together and go with the BW-1354 mechanical instead of the BW-1354 eletronic shift which is what I think we have right now. This will be more of a chore than I want but something needs to be done. Jot017's switch that he put on the Torque on Demand (yellow wire on the GEM) is a great solution but that wire is so tight in there it might be a stretch for me to splice it . Personally I would just like the manual transfer case because anything such as the control-trac that is that noisy can't be something that was designed very well. I can't see mercedes putting something in their vehicles that makes a loud noise and a thump, its rediculous what Ford has done. I'm sure you know what I'm saying......

 

[Jon_Herr]

TSB

I'll get the info on the reprogramming.

For people using big tires, I would try the fix with / without big tires.

Side wall flexing might be enough to cause automatic engagement of even the 'fixed' gem.

I would like to know what you find out after it's re-programmed.

Jon

 

[Jon_Herr]

TSB # and description

From: "http://flatratetech.com"

This description only talks about problems when turning, I know from personal experience that it will also take care of shuddering under acceleration.

Jon

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Article No.
97-21-15 SHUDDER OR BINDING SENSATION - IN TIGHT TURNS WHILE VEHICLE IS IN 4X4 AUTO MODE - VEHICLES BUILT THROUGH APRIL 1997
TRANSFER CASE - SHUDDER/BINDING SENSATION IN TIGHT TURNS WHILE VEHICLE IS IN 4X4 AUTO MODE - VEHICLES BUILT THROUGH APRIL 1997

Publication Date: OCTOBER 13, 1997

LIGHT TRUCK: 1995-97 EXPLORER

ISSUE:
A shudder or binding sensation in tight turns while in 4X4 Auto Mode may be experienced on some vehicles. The shudder is due to a high torque output from the clutch in some transfer cases.

ACTION:
Recalibrate the existing Generic Electronic Module (GEM) if the GEM is identified with engineering part number F77B-14B205-BB. The revised calibration commands a lower torque which allows the transfer case clutch to engage smoother so shudder or binding should not result. Refer to the following Service Procedure for details.

SERVICE PROCEDURE
Using Service Bay Diagnostic System (SBDS) machine, use the latest software release to recalibrate the GEM to command a lower minimum torque level from the transfer case. Follow the instructions below:

Select "Body, Chassis, Electrical" from the SBDS Main Menu.
Enter the Vehicle Identification Number (VIN) of the vehicle being serviced and continue to the "Body, Chassis, Electrical" menu.
Select "Module Reprogramming" under the "Category" scroll box, and "Module Reprogramming" under the "Tool" scroll box.
Follow all on-screen instructions, continue to "Module Reprogramming Procedure" screen and select "GEM Module, Shudder in 4X4 Auto Fix, 4X4 Auto Fix."
Again, continue and follow all on-screen instructions until the GEM module has been reprogrammed.
A copy of the log can now be printed to document what has been done to the vehicle.
If the new calibration does not satisfactorily resolve the concern, refer to TSB 97-3-14 for additional corrective actions.

OTHER APPLICABLE ARTICLES:
97-3-14

WARRANTY STATUS:
Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME
972115A Reprogram Generic Electronic Module (GEM) Using Service Bay Diagnostic System (SBDS) 0.4 Hr.

DEALER CODING
BASIC PART NO. CONDITION CODE
7A195 42

OASIS CODES:
303000, 508000, 703000, 703200

this one should do the trick
TSB # 97-21-15

--------------------
Warren Johnson < ==== thank this guy!
Airlake Ford Mercury

 

[briantf]

Very interesting stuff for a 98 owner

We got the straight-arm (straight-finger, perhaps?) from two different dealers about this issue. I can confirm that the stock 235 Wilderness tires on a stock 98 XLT had this problem - it's not a function of taller tires / sidewall flex.

The first dealer spent Ford's money cleaning the flash off the sensor ring and cleaning it off under warranty, then verifying that it was a TSB issue that had not yet been resolved (reprogrammed GEMS unit for shuddering under moderate acceleration to 45 MPH). Called several times about the fix, they never admitted it existed.

The second dealer initially said, oh yeah, we have to download it from Ford, that takes a long time. Called back twice, oh - not here yet, really slow download, we'll wait for the CD-ROM blah blah blah. NEW shop management comes in trying to unburn bridges, they said your tires are too loud (BFG AT KO) for us to hear the problem, go away. Of course i tried to get them to come here and look it up, but the search engine was down that instant in time (oh well).

I'm sure it doesn't do the CV's any good, nor the U-joints in the drive shaft. Almost 70K now, will definitely look into the yellow wire bypass. Maybe then my wife can get a good burn out on the way to school.

Thanks again,
Brian in CA

 

[Jon_Herr]

Bummer

There's real meaning to the phrase:
"You just can't get good help these days."

Good luck!

 

[Jim F]

Jon_Herr

I am a little confused, you refer to your 98 as AWD but the TSB referes to 4x4Auto mode. Do you have an AWD or 4x4 Explorer?

Also, has anyone gotten any hesitation from Ford on performing this TSB on a 98 4x4?

I have had this shutter ever since my 98 SOHC 4x4 was new and felt it was not normal. Mine seems to do more noticeably when pulling a hill when you can't get a run on it. In other word make a left turn onto a street that is fairly steep and the front shutters as if the front wheels are pulling faster than the rear. No, I know what you're thinking, I have 3.73 front and back. There doesn't seem to be any tire wear so I've just put up with it. I am glad to see the TSB and will attempt to pursuade Ford after the 4th of July.

One other thing I have tried which confuses the issue a bit. If I switch into 4Hi right before pulling the hill but after straighting out, the shutter is still there. I would think by lock the transfer case the shutter wouldnot be there. But on second thought, this shutter may be normal for dry pavement hill pulling and should not be there in auto when the front should not be engaging that much. I understand that more power is transfered to the front on heavier acceleration under 35MPH, maybe climbing a steeper street is casuing more power to transfer causing the shutter. Does this TSB increase the threshold before the power transfer starts or will I still have the shuter after the TSB is performed? I have felt the shutter on flat surfaces at times but am unable to determine what the circumstanses were.

Anyway, thanks for posting the TSB.

Oh, by the way, does anyone have access to the related TSB, 97-3-14, that this TSB references?

Thanks

 

[Robert]

Your Explorer will shudder if you put it in 4x4 High on the pavement and then make a sharp turn. That is normal as the stress tries to relieve itself, just before expensive parts break. I wouldn't advise putting it in High (or Low) on the pavement unless you have very deep pockets. The thing I noticed was you said it felt the same in High that it did in Auto. This points to the front end getting power when it shouldn't. Ford shouldn't give you any grief about applying the TSB to cure the shuddering. There will be a one hour labor charge (about $72) though if you aren't under warranty. TSBs aren't applied for free unless you are under warranty. Only a recall is done at no charge after the warranty.

 

[Jon_Herr]

Clarification...

> I am a little confused, you refer to your 98 as AWD
> but the TSB refers to 4x4Auto mode. Do you have
> an AWD or 4x4 Explorer?

I'm sorry, I was mixing terms. I have and 'auto' setting which to me means AWD, since you cannot truly take the vehicle out of 4 wheel drive.

The shuddering I'm describing occurs when traveling in a straight line in auto mode. It has nothing to do with intentionally entering 4 wheel drive on pavement and making turns. Doing so is a bad idea as stated by the previous post.

If I implied that TSBs should be applied for free then that's my mistake. My dealer did it for free as a 'by the way' while reprogramming for a steering groan TSB. ( I was not charged for the PCM reprogram either.)

While Ford's policy is to not do these 'firmware' upgrades for free, it varies from dealer to dealer.

I am fortunate enough to have a dealer that only charges for the big repairs - and I continue to support them for that reason.

Good luck!

Jon

 

[Robert]

Ford will reprogram the PCM at no charge for up to 80K miles. It and the catalytic converter are covered for 8 years/80K miles due to emissions requirements. That was the warranty my PIA dealer invoked when they reprogrammed my PCM at just over 50K miles. Unfortunately the Control Trac is controlled via the GEM and not the PCM. Reprogramming the GEM at no charge after the warranty has expired was a jesture of good will. You are fortunate to have a dealer near you that understands customer service.

 

[TPLYNCH]

Re: Clarification...

Originally posted by Jon_Herr
> I am a little confused, you refer to your 98 as AWD
> but the TSB refers to 4x4Auto mode. Do you have
> an AWD or 4x4 Explorer?

I'm sorry, I was mixing terms. I have and 'auto' setting which to me means AWD, since you cannot truly take the vehicle out of 4 wheel drive.

FYI - The V8's are the only true AWD as power is distributed to the front and rear wheels at all times. On the Control-Trac Auto, from a start, 5% of power is sent to the front wheels. After your speed exceeds ~30MPH, the system automatically sends 100% power to the rear wheels only, hence the Auto 4x4 is not AWD.

 

[Jon_Herr]

> After your speed exceeds ~30MPH, the system
> automatically sends 100% power to the rear wheels
> only, hence the Auto 4x4 is not AWD

Doesn't seem right, my engagement problem was occuring all the way up to highway speeds (75 MPH).

 

[Kinnish]

I just recently put a switch on the torque-ondemand wire on the GEM and wow ...what a difference...I love driving it now. I would highly recommend it


NO AUTO 4x4NOW...and 2WD Low

 

[Jim F]

Robert

I didn't say I pup it into 4Hi then make a turn. I said i put in 4Hi after making the turn and traveling straight up the paved street hill.

I have an extended warrenty with Ford so it should only cost me $50, but I have a few other things for them to check. I'm also considering having Ford do the first CA smog check just in case there are problems.

TPLYNCH

The facts I have been able to gather states that the auto 4WD switches to 2WD after exceeding 35MPH.

Jon_Herr

What is this steering groan TSB you had done? I had a left turn grunge sound that Ford fixed by replacing parts of the rack assy. The power steering does make some weird vibrations on the steering wheel at time and seems to cause the engine to change idle when stopped at a light. Is it possible to post the TSB content? Thanks

 

[Jon_Herr]

Steering TSB and parts

The TSB number is 98-21-1.

It involves replacing the high pressure side power steering hose and installing a bracket to stabilize the exhaust.

New steering hose part number:
F87Z3A719JA price: $109.94
Bracket part number:
F87Z5K249AA price: $81.13
U Bolt for Bracket:
F87Z5A231BA price: $13.45
total: $204.52

What I'm told by Ford is the steering pump sets up a harmonic vibration in the exhaust system that can be felt through the steering wheel and vehicle body.

That's what mine does - I haven't implemented this fix yet due to it's cost. I'm beyond my warranty and this is a mechanical TSB that would cost about $350 to have Ford do it. Parts alone are $204.

Not to mention that $81 for a stamped steel bracket is a bunch of @#$!.

I'm going to go the junkyard route as soon as possible.

If you compare a newer explorer '99 and up you'll see that the high pressure hose is this updated hose. Basically they made the rubber part a little longer so that where it clamps to the power steering pump bracket it is holding on to rubber and not steel.

The extra rubber probably also moves the harmonic frequency down into another range that is less likely to react with the exhaust.

Also - they re-program your PCM to make the engine spend less time in the 'sweet spot'. That's all I have done so far...

 

[Mascman]

This is the switch I installed.

I found it at Radio Shack. Since I don't smoke I removed the Cig Lighter and installed it there. It blends in well if your looking for something other than a toggle switch.