Shudder

[01MercGMLS]

I'm having an issue with my 2001 Grand Marquis LS. While I'm on the highway from 50 mph on up if I come to a slight uphill where you have to give just a little more throttle to maintain speed I get a wicked shudder. If I hammer on it the shudder goes away. If I let off the shudder foes away. It also seems to happen in top gear as the torque converter locks up.

Does anyone have any idea what's causing this and how I can fix it?

The car was a 1 owner car. A school teacher that drove it from Jerseyville, IL to St. Louis, MO. It has 157,000 miles on it and is in great shape. I can't fathom an older school teacher running the car hard so I don't think it's transmission damage. Thinking maybe wear or needs a fluid change.

I'm open to suggestions. Any help would be appreciated.

Thanks in advance,
Aaron

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[Gerry24]

I would suggest changing coils, plugs and checking the mass air flow sensor. And let the trouble shooting begin :burnout:

[TORINO]

Could also be an engine misfire, plug or coil. If it is the trans has it been serviced ?

[01MercGMLS]

I've only had the car for 4 months. The CarFax report is immaculate. The original owner was all over the service intervals so I'm almost sure it's been serviced. I'm just not sure how long ago. I'd have to go back and look. I wondered about a misfire but since I'm new to Ford and Mercury (Chrysler guy) I wasn't sure. Do these cars register a cylinder misfire? I haven't ever had a check engine light come on.

A tune up is in my plans but was waiting until next month. Had some unexpected expenses this month.

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[RubberCtyRauder]

MIsifre does not always register a check engine light, I believe it generally a repeat process where the same cylinder must misfire 'x" times over "x" time for it to turn on the CEL. Is the trans fluid correct level, clean and bright red? if it is dark, burnt smelling, past due for service. The factory tuning on these cars (cv, mgm, marauder) is based on gas mileage so the trans has poor shifting parameters by getting to OD asap then hunting for which gear to be in based on rpm etc..Torque converter shudder can happen. Often a fluid change helps, scan for codes even if one is not showing, check plugs, cops..especially if original. dirty MAF, vacuum leak.

[01MercGMLS]

One other thing I've noticed happening to mine and my buddy's car is the IAC howl. They're both the same year and roughly the same mileage. The research I've done says it's hard to get that to go away permanently. It does it while cruising on the highway, sitting at stoplights, and at startup. When it's howling the engine runs at a higher RPM. Could this be causing issues as well?

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[RubberCtyRauder]

clean the iac or change it, they are not expensive..they get dirty with carbon

[01MercGMLS]

clean the iac or change it, they are not expensive..they get dirty with carbonThank you for all your help. I love this car! I just need to get these couple bugs worked out and she'll be good to go.

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[Joe Walsh]

Flush the transmission....
My Mom's 1996 GM had the same problem...turned out to be the OD function in the transmission. It had just under 90,000 miles IIRC.
We changed fluid/flushed the trans and the problem was gone....drove smooth as glass after that.

[BLACKMARAUDER04]

Turn your OD off and test that theory.

[Marauderjack]

Torque Converter shudder.......add one 4 ounce bottle of FORD Friction Modifier......the smelly one for the rear end LSD.......if it goes away you are fine and can do a flush later......it's the same additive that comes in Mercon V fluid!!:beer:

This has worked for me from the Mid-90's in every CV I've had and I had 6 of 'em and ONE GREAT MARAUDER....used it in it too!!:bows:

[01MercGMLS]

Thanks guys... I'll try a flush next week. Today I fixed the annoying intake howl.https://uploads.tapatalk-cdn.com/20180526/42c7ec6b4df05fb18464b02f8bf4f6 12.jpghttps://uploads.tapatalk-cdn.com/20180526/8f4601da64a29072f44cea9342442d 52.jpghttps://uploads.tapatalk-cdn.com/20180526/ad67fa60cfa4206fc616fe9168f000 7e.jpg

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[01MercGMLS]

With the OD off it still does it as the converter locks and unlocks.
Turn your OD off and test that theory.

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[01MercGMLS]

I'm going to buy a 4 ounce bottle of friction modifier today and give that a shot. I'll flush the trans next month and add another 4 ounce bottle. I want to try to make this tranny last.

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[Marauderjack]

Go for it......it will not hurt a thing and hopefully fix your problem!!:beer:

WARNING......DO NOT SPILL ANY...IT STINKS FOR A LONG TIME!!:shake::eek:

[01MercGMLS]

Go for it......it will not hurt a thing and hopefully fix your problem!![emoji481]

WARNING......DO NOT SPILL ANY...IT STINKS FOR A LONG TIME!!:shake::eek:I'm also buying a long funnel. I don't even wanna smell this crap.

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[Merc-O-matic]

Change AT fluid
New Mercon V
Shudder should go
away.
Had same problem
with my '97 GM.

[01MercGMLS]

My only concern is... I am not a mechanic extraordinaire. I tend to have my work done at shops or by friends. I'm not sure that is a job I can do in my driveway safely. If I'm taking it somewhere it would be a quick lube place that will hook it to the machine. That's $100. I'm also not sure that they are going to use the correct automatic transmission fluid. I'm willing to try the friction additive to get it to stop. I don't have the money to do the $100 change right now. If it will stop shuddering long enough for me to save up the money... Like 1 month from now... I will do the change then.

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[Marauderjack]

As long as your fluid is fairly clean and glazed friction surfaces are the problem the Friction Modifier will fix it in just a few miles and it will last quite awhile......if it doesn't fix it you'll know you have bigger problems!!:cool:

Ford Techs in Charlotte used to recommend the Friction Modifier treatment first and if it worked you could do a flush later........inexpensive experiment that WILL NOT HURT A THING!!:beer:

[RF Overlord]

Your issue is most likely the infamous torque converter clutch shudder. Adding the friction modifier will certain help in the short term, but it is a bandaid. If the FM additive is depleted, then so are all the other additives in the AFT that protect the transmission. Best course of action is to get a complete fluid exchange, using Mercon V only. Do not let anyone tell you they use some "universal" fluid with an additive to "make it into Mercon V".

If you can't find a shop that will do a complete fluid exchange and replace the filter, dropping the pan and changing the filter is very simple, even for someone not "extraordinaire". If you can change the oil in the engine, you can do this. No special tools needed, just a 10mm socket.

[Marauderjack]

Bob.....it may be a Bandaide but I've seen it work for a couple years IF the fluid is not burned!!;)

Like I said....it's an INEXPENSIVE way to find out if clutches are glazed....heck I put a bottle in my Marauder every 15K miles......NEVER a problem!!:bows:

[01MercGMLS]

I'm putting it in tonight then driving 53 miles to work tomorrow. I'll know very soon if it fixes the issue.

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[RF Overlord]

'jack, I didn't mean to disrespect your suggestion. It's a good way to see if the issue is caused by depleted fluid or if it's something unrelated to the transmission.

[01MercGMLS]

My parts store didn't have the Ford friction modifier. They pointed me this direction. It seems to have fixed the issue.https://uploads.tapatalk-cdn.com/20180527/426a1fe9f79169cad61e7bf93220b5 6e.jpg

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[Marauderjack]

Glad it seemed to work but I wouldn't recommend using that!!:shake:

Get the OEM Ford FM from your Ford Parts counter!! :beer:

[01MercGMLS]

I figured that. I'm going to have the fluid changed this coming Friday. I'll put the original Mercon V in it and call it a day.

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[Marauderjack]

You should be good to go with fresh fluid....glad it wasn't anything serious!!:beer:

[FordNut]

Why not get parts and service at the Ford dealership?

[01MercGMLS]

I don't want to pay the exorbitant labor rates when I can do the work myself. I have a buddy that used to own a shop that knows exactly how to do this stuff. He's going to help me out. Free labor.

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[FordNut]

I was just referring to your comments comparing the correct friction modifier vs whatever the parts store has, or the quick lube fluid change that may not use the right fluid vs the Ford dealer's service dept that knows which fluid to use.

[01MercGMLS]

I get it. Sorry. The reason I don't go to a Ford dealership is because the one near me sucks! I was told by my mechanic buddy this would be a good alternative. If this didn't fix the problem there would be bigger issues we would have to delve into. This fixed the problem so he recommends changing it with Mercon V by doing a pan drop and filter change as well.

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[Marauderjack]

Ford OEM FM was about $6.00 a bottle last time I bough it......I bet the parts store stuff was more expensive!!:confused:

https://www.tascaparts.com/differentials-friction-modifier-4-oz-cm-19546-a1?parent=1033

[01MercGMLS]

I don't think it was that much more. Maybe $7. I was referring to having the Ford dealership do the work. As far as the parts or fluids... I will get those from the Ford dealership if I have to.

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[01MercGMLS]

Since there isn't a Ford dealership in my town and I'm pretty partial to giving people who run businesses in my town the business... I tend to go there.

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[RF Overlord]

Despite its name, Dr. Tranny Instant Shudder Fix is not snake oil. It's actually highly regarded on BITOG. Glad it helped prove the issue is simply worn-out fluid.

If you're not going to have a complete fluid exchange performed, at least install a drain plug (https://www.summitracing.com/parts/BMM-80250) in the pan so you can do drain & fills more easily in future. There's no need to replace the filter after the initial replacement. I recommend doing at least one additional drain & fill the next time you change the oil in the engine.

[01MercGMLS]

I'm not sure if the previous owner ever changed the filter. I figure better safe than sorry.

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[Agent2006]

Dr. Tranny Instant Shudder Fix

I got this stuff from NAPA and used it in my 2000 GM, works great for awhile 10,000 miles or more then I had to add some more : 139,000 on it at the time. Be careful, when you snip the end off the vinyl tube to get ready to pour it it is dark red and really runny don't spill it and it stinks don't spill it on yourself. But works great.

I seem to remember Dr Tranny was around $7 bucks

[01MercGMLS]

It did work and you are right about the smell and the mess. My biggest issue was trying to figure out how to get the little tube down to the fill hole without spilling all of it.

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[HotRaud90]

Not to hijack your thread, sir, but I have also had the torque converter shudder as a nagging issue. I know it's the torque converter causing the issue because I don't get the hesitation in power delivery or shudder when I'm not in OD. It only happens when I'm in OD. All power delivery from engine to tranny in 1st, 2nd, and 3rd is smooth. If I'm not careful in how I hit the gas while in OD, I get one hard shudder upon acceleration.

A couple years back, I did a complete flush of the system as many are recommending here. I did it @ 93k mi. I followed Marauderjack's advice using the bottle of friction modifier. Ever since then, I have dropped the tranny pan every other oil change and exchanged 4 qts of fluid. The flush and friction modifier helped substantially for some time, but that was it - just for a time and then it returned. Very frustrating. Do I have a bad torque converter that need to be replaced? Or do I need to look into another flush not even 30k miles later? I'm at 120k now.

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[RF Overlord]

During the flush at 93k and your subsequent pan-drops, did you use Mercon V fluid?

Since you say you do a pan-drop every other oil change, for God's sake save yourself from the ATF bath each time and install a drain plug. Makes it WAY easier and cleaner. Also note that it is not necessary to change the filter after the initial change.

[01MercGMLS]

During the flush at 93k and your subsequent pan-drops, did you use Mercon V fluid?

Since you say you do a pan-drop every other oil change, for God's sake save yourself from the ATF bath each time and install a drain plug. Makes it WAY easier and cleaner. Also note that it is not necessary to change the filter after the initial change.What he said. Lol

Trust me when I say this... These guys know their stuff.

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[HotRaud90]

During the flush at 93k and your subsequent pan-drops, did you use Mercon V fluid?

Since you say you do a pan-drop every other oil change, for God's sake save yourself from the ATF bath each time and install a drain plug. Makes it WAY easier and cleaner. Also note that it is not necessary to change the filter after the initial change.

Yes. Mercon V used every time. Haven't had an ATF bath...yet! I plan on a drain plug for the next time I drop the pan.

Good to know about the filter. It has only been changed once, as far as I know. What's the reasoning behind not changing it more than once?

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[RF Overlord]

The filter in the transmission is only there to catch wear materials generated during break-in...generally accepted to be 10,000 to 15,000 miles from new. After that the rate of wear material generation drops so low as to be inconsequential. Also, there is a magnet in the pan to collect any ferrous wear material. This is why it is recommended to change the filter (and clean the magnet) with the first fluid change, but not necessary again after that.

Since the transmission is essentially a sealed unit, there are no concerns about ingestion of particles through an air intake, nor are there any concerns about combustion/blowby contaminants or fuel dilution such as exist in the engine.

[HotRaud90]

Good stuff. Figured as much, and your knowledge confirms it. Thanks.

Back to my question about the flushing, now that I've clarified I use Mercon V and I've done a flush and a couple of fluid exchanges: time for another go at the flush with friction modifier (last one was 27k mi ago) or look deeper into possible TC issues? Is the TC the place I need to look if fluid changes are not helping?

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[RF Overlord]

Send a PM to 88grandmarq...he's the transmission guru here. If you are using Mercon V, and have done so since the flush, you shouldn't be experiencing shudder due to depleted fluid in such a short time. It *may* be a torque converter issue.

Just for the sake of completeness, verify you are actually experiencing TC shudder by doing the following little test:

Leave O/D on. When you start to experience the shudder, keeping your foot steady on the gas, use your other foot to gently tap the brakes, just enough to light the lights. If the shudder stops immediately, then you likely have TCC shudder. If it does NOT, then you may have a misfire.

[HotRaud90]

Send a PM to 88grandmarq...he's the transmission guru here. If you are using Mercon V, and have done so since the flush, you shouldn't be experiencing shudder due to depleted fluid in such a short time. It *may* be a torque converter issue.

Just for the sake of completeness, verify you are actually experiencing TC shudder by doing the following little test:

Leave O/D on. When you start to experience the shudder, keeping your foot steady on the gas, use your other foot to gently tap the brakes, just enough to light the lights. If the shudder stops immediately, then you likely have TCC shudder. If it does NOT, then you may have a misfire.

I'll see if I can get a hold of 88grandmarq. He does know his stuff.

I'll try that test tomorrow. However, I predict it will be very hard to do. The "shudder" I'm experiencing is one singular bucking motion. It is not multiple hiccups or shuddering. Since it is one quick buck, I don't know if I'll be able to properly diagnose using that test.

I've seen many people, including guys on Ford truck forums, say that it can be related to a bad COP or the plug itself and can commonly be misdiagnosed. Ugh...

[RF Overlord]

The "shudder" I'm experiencing is one singular bucking motion. It is not multiple hiccups or shuddering. Since it is one quick buck, I don't know if I'll be able to properly diagnose using that test.

I've seen many people, including guys on Ford truck forums, say that it can be related to a bad COP or the plug itself and can commonly be misdiagnosed. Ugh...Ah-HA! That "one quick buck" sounds familiar. Back in 2013, Mary had a very similar effect with her Marauder...I likened it to a "sneeze"...it almost felt like someone had turned the key off for just a fraction of a second and right back on again. Long story short, after trying everything everyone could think of, I ended up removing the 30,000-mile Autolite 104 spark plugs and replacing them with NGK 4177s, at Marty's suggestion.

Bingo. Problem went away. She sold the car to SergntMac in 2016, so I don't know if the problem has recurred since, but I don't believe so.

Funny thing is, the Autolite plugs all LOOKED fine.

[HotRaud90]

Ah-HA! That "one quick buck" sounds familiar. Back in 2013, Mary had a very similar effect with her Marauder...I likened it to a "sneeze"...it almost felt like someone had turned the key off for just a fraction of a second and right back on again. Long story short, after trying everything everyone could think of, I ended up removing the 30,000-mile Autolite 104 spark plugs and replacing them with NGK 4177s, at Marty's suggestion.

Bingo. Problem went away. She sold the car to SergntMac in 2016, so I don't know if the problem has recurred since, but I don't believe so.

Funny thing is, the Autolite plugs all LOOKED fine.Hmmm. Interesting. I would never guess plugs because I replaced them about 30k mi ago. Worth looking into. Thanks for letting me know about your experience.

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[HotRaud90]

Ah-HA! That "one quick buck" sounds familiar. Back in 2013, Mary had a very similar effect with her Marauder...I likened it to a "sneeze"...it almost felt like someone had turned the key off for just a fraction of a second and right back on again. Long story short, after trying everything everyone could think of, I ended up removing the 30,000-mile Autolite 104 spark plugs and replacing them with NGK 4177s, at Marty's suggestion.

Bingo. Problem went away. She sold the car to SergntMac in 2016, so I don't know if the problem has recurred since, but I don't believe so.

Funny thing is, the Autolite plugs all LOOKED fine.Overlord, just coming back around to this after thinking about it some more. Do you recall when that "buck" took place? Was it across all gears and rpm ranges? Mine only occurs in OD when the RPMs are sub 2100. This translates to about 45-60 mph after the TC has locked up. Just want to check with you to see if you can remember if your experience was similar or different. Thanks.

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[RF Overlord]

If I remember right, it occurred mostly when the throttle was opened after coasting. I only got to drive the car around town a couple of times and never on the highway. Mary may remember more details.

[HotRaud90]

If I remember right, it occurred mostly when the throttle was opened after coasting. I only got to drive the car around town a couple of times and never on the highway. Mary may remember more details.Gotcha. That's when mine happens as well. OD, coasting around 45 - 60 (i.e. after TC has locked up), and opening the throttle after the coast. Maybe you can get some additional details from Ms. Mary and let me know? Thanks for your helpful input.

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[01MercGMLS]

So... here's a question for you guys... I've seen a few posts referencing the Dorman Tranny Pan and none of them sound good. Is there something wrong with the Dorman Pan...?

I need to do a pan drop but I don't want to have to drop it every time I change the tranny fluid. So... I've been looking into a Dorman Pan with a drain plug. I figure it's easier to just put a different pan on that already has a plug rather than drilling the original pan and installing a plug.

Any insight would be appreciated. Thanks in advance.

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[RF Overlord]

The only thing I see about the Dorman pan is that the drain plug is on the front of the little well, where the Ford "U-Haul" pan has it on the back side. Does that matter? :dunno:

Honestly I use the B&M universal drain plug on all my cars. It's only $10 and all you need is to drill a ½" hole.

[01MercGMLS]

The only thing I see about the Dorman pan is that the drain plug is on the front of the little well, where the Ford "U-Haul" pan has it on the back side. Does that matter? :dunno:

Honestly I use the B&M universal drain plug on all my cars. It's only $10 and all you need is to drill a ½" hole.Good info. Thank you sir!

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[BUCKWHEAT]

I would suggest changing coils, plugs and checking the mass air flow sensor. And let the trouble shooting begin :burnout:

Agree. Common issue.

[01MercGMLS]

Agree. Common issue.Been there done that. Shudder remained. Added a tube of Dr. Tranny... gone. Still need to do a tranny fluid change.

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[Invective]

Don't know if this issue is related to what I've experienced or not. The thread did capture my attention though.

Back around 2001, I modded a '98 Mustang GT at 22k miles with the 4R70W. Gears, driveshaft, shift kit, girdle cover, TC, CAI, underdrive pulley, custom tune. A day or two after completion, I experienced a shudder, stumble and stall at low speed. Restarted the car and it ran fine. Tuner stated to keep him informed. Car ran flawlessly until I crashed it at 101k miles in 2011 - complete tuneup at 96k miles a year or two earlier.


Fast forward to 2018. My '04 bone stock Marauder with 41k miles just came out of MartyO's shop with nearly identical mods. Not long after leaving the hotel in Hiram, GA this past sunday the Marauder experienced nearly identical symptoms although it didn't stall - car regained its composure and I completed the remainder of my 230 mile trip flawlessly.


My thinking in both incidents is the ECM is/was adjusting to its new operating parameters?

[01MercGMLS]

Mine was just old transmission fluid. I bought this car from a dealer but I'm the second owner. The carfax showed all the maintenance records and they were flawless. The only thing I didn't notice until later is there was no mention of a transmission flush. I added Dr. Tranny and the shudder stopped. Shortly after that I did a fluid change. Still no shudder.

Yours may well be a computer issue related to the new programming.

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