By on January 20, 2010

Marquis-Mark and the funky bunch

Jeremy writes:

Hello Sajeev, I have a 1993 Mercury Grand Marquis that I picked up from a family member a couple years back. I registered the car in my name with only 37,000 miles on the clock, it now has just over 51,000. The car was garage kept for years. I have updated the fuel filter, spark plugs, tires, air filter, and the regular oil changes.

After driving the car for a while I noticed the transmission shifted with a slow “shudder” from 3rd to 4th gears. The transmission seemed to shift smoothly under light acceleration but mild to brisk acceleration is accompanied by the transmission shudder.

I checked around online and found that this is not an isolated case. In fact, Ford released a TSB on the issue with this transmission. The TSB stated the transmission fluid needed to changed to handle the problem. I took the car in to an Ammaco last month for the fluid and filter swap. I picked up the car for a test drive and the transmission shifted without the shudder. Within a couple of hours the shudder was back.

I am completely lost on this issue. I do not know if the transmission shop dropped the ball on the fluid swap or if the transmission might be shot. You help is greatly appreciated!

Sajeev Replies:

And here I thought the mighty-mighty Marquis was completely bulletproof! Every website has the Ford Panther Chassis faithful blogging to that effect.  Of course, Ford’s less-than-stellar tranny track record since the dawn of automatic overdrive transmissions is common knowledge, even to the fanbois.

Luckily this problem has a quick fix, especially at your mileage: damage to the transmission’s hard points aren’t likely. Yes, you needed the switch to Mercon V ATF (Mercon III was from the factory) but sometimes that isn’t enough to fix the shudder. Because there’s no miracle cure in a bottle.

Well, except when there is. Ford had a similar transmission problem with Explorers circa 2004 (rough engagement into drive). They couldn’t use the Mercon V excuse again, after 10-ish years of using it at the factory, so they recommended a friction modifier: in this case, a bottle of Lubeguard Red.  People on various Fat-Ford forums agree, and I my mother’s (former) Lincoln Aviator absolutely loved to shift after the dealer added it.  Or so I remember.

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18 Comments on “Piston Slap: Friction Modification for The Mighty-Mighty Marquis?...”

  • avatar

    So…. What’s the quick fix then, if not the one in the bottle? Because it sounds like Jeremy already tried that…

  • avatar

    Take it to a Lincoln-Mercury dealer and see if they can figure it out for $200.  If they recommend a new transmission forget about it.  Instead, drive it carefully and forget about the shudder.  Before long you will have learned to live with it.

    • 0 avatar

      Every time I took an old American car to its respective dealership service department, I felt like I was overcharged and disrespected.

      I finally told ’em to FOAD when a salesman was allowed to put a new (1993) Continental sales brochure inside my 1983 Continental before they gave it back to me. Hence my first purchase of a Helms (not Haynes) manual.

      More to the point, this moment was the genesis of the Piston Slap series. It just took a while to get the rest of the system working. :)

  • avatar

    I’ve owned two Mark VIII’s with the same problem.  If the Mercon V tranny fluid doesn’t fix the problem, there is another possibility.  The most likely is that you have an ignition problem ( bad plugs, wires, coils ) that “feels” like a tranny problem.  This sometimes will manifest itself as a shudder during the 3-4 shift.

  • avatar
    cRacK hEaD aLLeY

    Most DeSade owners shudder while they drive , so the resulting harmonics cancel each other out. If you wait long enough, your problem will be solved.
    Over-maintaing  your Marquis-De Sade is so, so wrong.  At 51 clicks it does not want new plugs and fuel filter and all this new crap. Save that for the GT2.  The less you mess with it, the more stable it will be.  And the transmission is shifting, so it’s working. And that is good. Switch off the hearing device.  Ease off a bit just before the shift point – as if you just remembered you forgot to take your stroke medication. Helps tremendously.   As a last resort, leave it  in 2 instead of D with the hearing device still off.

  • avatar

    As long as it looks better than the one in the pic, try switching fluid, and start looking for transmissions shops that cost less than the dealer but are still trusted.  (Ask around.)  You could have your local Pep Boys read the codes of the engine and give you a diagnosis too, just to make sure it’s not desperately in need of a tuneup or something like that.  Codes don’t always make the check engine light come on.

  • avatar

    It’s probably coming from the torque converter clutch as it tries to go in and out of lockup in the top gears. As others have suggested, try completely flushing it and refill with Mercon V. If that doesn’t work, then the damage is done and it will need a torque converter.

    Edit: on an unrelated topic, speaking from experience: don’t try pushing the oil change intervals on these early 4.6L mod-motors…I don’t know how many of these I’ve seen sludged by 50-60k with verified oil changes every 5K miles. Unless you run synthetic, I wouldn’t push one of these engines more than 3K between changes.

    • 0 avatar

      I agree on the oil change intervals.  I err on the side of caution and change oil every 2500 – 3000 kms on my early mod motor.  Plus I live in Saskatchewan where you’d have to be crazy to observe the 5,000 km (yes, I know it reads 5,000 mi. above) interval, especially in winter.

  • avatar

    Check the EECIV codes for trans codes. 628 is a common one, indicating weak pump pressure and impending doom. If you can get a trans made after 98 they fixed the problem with the valve body that causes it.

    There are other codes but 628 is a famous one. Rebuilding requires new parts as the old ones self destruct. Changing fluid, or different fluid can’t fix a bad design and BTT Ford  realized their mistake it had been out a few years.

    I could be wrong of course but it costs 30 dollars for a code scanner and can answer a lot of questions.

  • avatar

    My answer was truncated.  Fix is in the works…

  • avatar
    Don Gammill

    FYI, You don’t need a code scanner to pull codes from most Ford EEC-IV PCMs like this car has.

    Any older Panther-specific (or early-’90’s Ford-specific) Haynes repair manual will provide clear instructions on how to jumper two of the pins on the diagnostic harness connector so that any/all codes will flash on the Check Engine light (just carry out the prescribed brake/throttle/steering wheel inputs per the procedure and count and record the number of flashes to get the code number).

    I’ve done this for years with several pre-96 Ford vehicles and have never had a false code (even when some very expensive generic scanners did give completely false codes).  If you know what you’re doing, you can even prompt some of the diagnostic routines this way (i.e. cylinder balance test, etc.).

  • avatar

    Just to reiterate the edit to the blog: a bottle of Lubeguard Red is known to fix this problem on the 4R70W transmission.

  • avatar

    I had a 95 Cougar v8 that ate spark plug wires for lunch. They are cheap and easy to change (fortunately). The back plugs on both sides cross over to the distributor on the opposite side. (two distributors, front side up on top) The wires are stupidly long. The problem manifests itself as a shudder which is virtually indistinguishable from tranny shudders. In fact, the first time it happened most people said it was that. After more miles and years, i began to detect it immediately each time and could correlate it to a damp period. When the tranny finally did get weak, it felt as if i were doing a burnout at a green light (but the tires weren’t slipping obviously).

  • avatar

    Wow, I was about to recommend Lubeguard Red based on my recently departed GMarq.

    Yes, it helps.

  • avatar

    Go get it checked out for any cruise control switche recalls..

    Lord knows they have issues going back 20yrs.

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