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Dave Park · 05-13-2011, 06:27 PM

Hi all,

My F150 FX4 (5.4L) 83K miles has a transmission problem. It's the common "torque converter lock-up" problem - a shudder like driving over rumble strips or rough road as the torque converter shudders into lock-up at 45-50 mph.

I have dropped the pan and replaced the fluid and filter - it's not possible to replace the fluid in the torque converter as it doesn't have a drain plug (none after 2004 do) - so I repeated that process three times. This way I have swapped out 87.5% of the fluid.

There is no unusual debris in the pan - nothing on the magnet, with 1000 miles between each of these changes.

This hasn't resolved the problem at all.

If I accelerate harder (to force unlocking) or if I hold the accelerator and activate the brake, there is no vibration, so therefore it is strictly a torque lockup issue and not a transmission or driveshaft-balance issue.

I'm not looking forward to dropping the tranny to replace the torque converter, but it's a big, heavy job and I'm not up to it right now.

Does anyone know the 4R75E transmission well enough to tell me a chain of what else to look at? I have searched F150 forums with little new advice beyond "change the fluid, or change the converter"...

Stuck!

RBolton · 05-13-2011, 07:01 PM

If it's a "common" problem then there should be a "common" solution. I don't know much about Fords but usually in this day and age the first thing to check for is a software update. Your Ford dealer should be able to tell you if there is one that addresses this problem.

There are different schools of thought on changing the fluid versus exchanging the fluid. A fluid exchange usually replaces close to 99% of the fluid and will sometimes correct issues like this. But chances are your three changes were enough.

war eagle · 05-13-2011, 08:55 PM

The only luck I have ever had resolving torque converter shudder is a fluid flush where the transmission cooler lines are hooked to a machine that has a large fluid reservoir that allows all of the fluid to be exchanged with the transmission at operating temperature and engine running.

Doing a drain and drop of the pan just won't get all of the contamination out of the fluid. Doing it 3 times is better but still for a 4R75E with a 13.9 qt capacity and assuming 7 quarts with a drain and drop of pan and 3 cycles, the transmission still has over 12% old fluid remains in the system.

Best wishes in resolving as the shudder is an aggravating condition.

Steve

Dave Park · 05-13-2011, 09:45 PM

Aggravating is an understatement. I feel I cannot tow with this truck. I have driven it so little recently because of this. I have always taken care of the fluids and used name brand full synthetics, and the transmission gets a 25k change and filter.

The shudder seems to have been caused by a transmission additive "Lucas Oil's Automatic Transmission Fluid Conditioner" which was added without my consent. I follow the adage that you don't treat the fluid, you replace it. The shudder started within days of that "service"...

I understand there is some kind of sensor or relay that operates the clutch. Does anyone know if it is accessible without dropping the whole transmission, or if I should just bench the transmission, replace the torque converter, the relay/controller/whatever and/or the sensor? Or is there some other way the converter determines when to lock up and activates? I've seen the drawings or videos about the principles of its operation, but they gloss over the specifics of how it locks up in a 4R75 family transmission...

ROBERTSUNRUS · 05-13-2011, 10:04 PM

Hi, while I was still working at the Ford dealer this concern was fixed like this: (1.) Instead of doing a trans service at 30,000 miles, Ford reduced it to 21,000 miles. (2.) Replace all of the fluid and filter. (3.) Drive for at least 500 miles. [not towing] (4.) If shudder stopped, you're OK. If not, replace torque converter.

Just changing the fluid is not enough; You have to put some miles on it.

Dave Park · 05-13-2011, 11:41 PM

Okay.

Should I disconnect the battery to force the computers to retrain?

war eagle · 05-15-2011, 12:51 PM

Dave - I think disconnecting the battery is worth a try to retrain the adaptive controls for the transmission. Whether you disconnect the battery or not, Bob is right - you need to drive the truck and see if the shudder doesn't improve. At the Ford Truck Enthusiast forum, there is a retired Ford Transmission Engineer (Mark K.) who is a wealth of knowledge and may be able to help with the details of the electronic and hydraulic control systems - you might post a question in the correct forum area and see what he has to offer.

Steve

Dave Park · 05-16-2011, 02:33 AM

I've driven the truck 250 miles since then. There was an immediate slight improvement in the behavior - it happens across a smaller speed/rev range and feels a bit less severe - but in 250 miles of driving the behavior hasn't changed any further.

I haven't forced the computer to retrain yet. It has also been suggested that I replace the filter again now the flush/cleaning process is almost complete - since the new filter will have trapped all the gunk loosened by the detergents in all that new Mercon V.

Tomorrow. I will also be checking the MAF sensor and check/clean the EGR valve.

I'll keep you all posted.

pappy19 · 05-19-2011, 12:23 PM

You might also consider adding a Transgo tugger Shift kit to the tranny and also consider a Superchip programmer. The shift kit is around $100 and the programmer is around $300, both will dramatically improve your shifting and should eliminate your shudder. The $400 expense is alot less than the $1500 for a new converter and $2500+ for a new tranny. I have both on my wife's 2007 Lincoln LT(a glorified F-150) and it tows like a champ. For additional safety I also added a Summit Racing external tranny filter for another $40. One can't be too careful when it comes to tranny's.

Pap

withidl · 05-19-2011, 01:47 PM

Quote:

Originally Posted by Dave Park

Aggravating is an understatement. I feel I cannot tow with this truck. I have driven it so little recently because of this. I have always taken care of the fluids and used name brand full synthetics, and the transmission gets a 25k change and filter.

The shudder seems to have been caused by a transmission additive "Lucas Oil's Automatic Transmission Fluid Conditioner" which was added without my consent. I follow the adage that you don't treat the fluid, you replace it. The shudder started within days of that "service"...

I understand there is some kind of sensor or relay that operates the clutch. Does anyone know if it is accessible without dropping the whole transmission, or if I should just bench the transmission, replace the torque converter, the relay/controller/whatever and/or the sensor? Or is there some other way the converter determines when to lock up and activates? I've seen the drawings or videos about the principles of its operation, but they gloss over the specifics of how it locks up in a 4R75 family transmission...

Dave, I was a Lubrication Engineer with Texaco Lubricants Co some years back so I have some very good knowledge in this matter.

The clutch packs and bands in an auto box are EXTREMELY sensitive to any modifications of the transmission’s fluid friction characteristics. Transmissions are designed to operate with hydraulic oils/fluids formulated to VERY specific friction characteristics, i.e. even though the oil lubricates and cools the transmission, it also has friction additives which affect the rate and smoothness at which the clutches and bands are applied. Even a VERY slight change in these friction characteristics will cause what you are experiencing.

The "Lucas Oil's Automatic Transmission Fluid Conditioner" which was added without (your) consent IS the problem. What has happened is the Lucas additives have contaminated / changed the oils friction characteristics and have probably impregnated the clutch and band materiel.

Your only real recourse is to do a very COMPLETE flush and filter change of the transmission; drive the vehicle a few hundred miles and if that doesn’t mitigate the problem do a 2nd COMPLETE flush and filter change. As the Lucas additives are diluted the problem will probably gradually abate.

Harleyyat · 05-19-2011, 01:50 PM

I have a 96 Merc Grand Marquis and these cars are notorius for torque converter shudder. I had the fluid changed and all was okay for maybe 5000 miles and then it started again. I found that O'Reilly's sells a product especially for shudder. It is called Lubegard - Dr Tranny Instant Shudder Fix. It really works in the Merc. I put it in and voila, no shudder. The quantity is so small that I don't drain any fluid, just add it to the tranny. It's good for about 10000-12000 miles.

Lubegard 19680 - Dr. Tranny Instant Shudder Fixx | O'Reilly Auto Parts

ibgl6 · 05-19-2011, 03:32 PM

I have a 99 surburban and mine seems to shudder when coming to a stop would that also be a torque converter problem or do I just need a trans. rebuild it does have a 150,000 miles on it....SAM

withidl · 05-19-2011, 04:34 PM

Quote:

Originally Posted by Harleyyat

I have a 96 Merc Grand Marquis and these cars are notorius for torque converter shudder. I had the fluid changed and all was okay for maybe 5000 miles and then it started again. I found that O'Reilly's sells a product especially for shudder. It is called Lubegard - Dr Tranny Instant Shudder Fix. It really works in the Merc. I put it in and voila, no shudder. The quantity is so small that I don't drain any fluid, just add it to the tranny. It's good for about 10000-12000 miles.

Lubegard 19680 - Dr. Tranny Instant Shudder Fixx | O'Reilly Auto Parts

If an auto box is maintained basis mfg. specs, and not subjected to abuse (i.e. shock loading, over heating), there should never be a need for "snake oil" additives.

r carl · 05-19-2011, 04:57 PM

I would be contacting Lucas.

pappy19 · 05-19-2011, 05:34 PM

You should also frequent www.bobistheoilguy.com as this is the premier oil site for all types of oil questions.

Pap

Dave Park · 05-19-2011, 06:53 PM

I just wanted to add that I am a firm believer in regular transmission fluid changes, and that this is the cheapest, best maintenance for your tranny. Simply put, if I was to think of adding an additive, it is better to just replace the fluid.

The only problem with the F150 is that the torque converter doesn't have a drain, so replacing ALL the fluid is a little more complicated.

I have tried to replace it at the transmission cooler to do a full flush, but have not worked out how to disconnect it. I have identified which is the IN and OUT line to the cooler though (the IN line warms first, and the OUT line is cooler when there is airflow through the cooler).

I will look at the additional filtration option mentioned several posts above.

I just want you all to know that I deeply appreciate all your advice/comments.

Airstreamer67 · 05-21-2011, 01:19 PM

Dave, I installed a $10 oil drain plug in my Ford's auto transmission pan. This allows an easy oil drain of about 7 quarts of oil, or about 50% of the total capacity. I change the transmission oil about every 30,000 miles or less, and occasionally change the filter.

I would recommend that you install such a drain, and change the oil again. Fresh oil is a known antidote to converter shutter in Ford transmissions, although, of course, nothing can be guaranteed.

Baseman · 05-21-2011, 01:41 PM

I had a 96 Ford, it required a special tool to disconnect the trans cooler lines at the radiator. It was less than 10 bucks at the parts store. It was 2 silver bars rivetted together in the middle with split cylinders on the ends. You wiggle it into the groove around the trans lines at the radiator and the line just slips out. Be carefully not to lose the o-ring on the end of the line.
The little tool was in the Help section.

Dave Park · 05-25-2011, 01:48 PM

I have now driven 400 miles, and I can report that yes, the torque converter is locking up better than it used to and that the behavior is about 40-50% better than it was.

I will repeat with another fluid change after the 500 miles, and see where that leaves me.

slowmover · 05-25-2011, 02:11 PM

I'd try some Auto-RX. Have used it in numerous family vehicles in all systems. It does what it says it will do.

Use according to directions and have fluid changed via machine. It generally takes several quarts more than ATF capacity to finish the job.

A shop using a Clore Automotive T-Tech machine is also recommended as the machine "uses" the vehicle pump, NOT adding any pressure to the system. (I bring my own fluid).

T-Tech

I've oil analysis reports on one vehicle -- bought new and only serviced by me -- where synthetic was used after break-in and ARX showed improved wear numbers when used after 60k.

Fluid changes on this truck was the first thing I did after purchase, and ARX was used in all systems prior to change-out (again, according to directions).

I would also recommend the use of SCHAEFFER'S #204 ATF(if compatible).

(And glad to see you posting again).

.