Help Needed: Drivetrain Shudder in OD

[HotRaud90]

I've recently discovered a shudder/stumble/lurch that feels like it's coming from the drivetrain of the car. I have narrowed it down to when the car is in OD. If I'm coasting at speeds around 40+ in OD with my foot off the gas pedal and then give the pedal a slight stab, the car bucks slightly from the drivetrain area of the car, and then it continues to accelerate as normal. It's not a bone jarring buck, but it's enough to worry me. If I push down the pedal very gently and evenly, I don't experience the problem.

I did some testing and it seems the only time it happens is in OD. I hit the OD button and kept it in 3rd and tried to replicate the symptoms that appeared in OD, but everything seemed fine. I would slightly stab the throttle in 1st, 2nd, or 3rd from a coast and it was nothin but smooth, even acceleration. The car shifts gears smoothly as well.

It's not a COP related issue as I changed all of them with plugs ~6k mi. ago. I also recently did a drop pan, drain, and fill for the tranny less than a month ago and I had done another 12k mi before that. I also cleaned the throttle body thoroughly this past weekend so it's not a sticky throttle body issue where it lags before it opens.

Any experience or advice on this issue?

[fordnut02]

My 97 Explorer just starting doing this , its a converter problem,

took it to My transmission man , He said change fuild it out in bottle of Ford Friction Modifier 4.5 OZ

[fastblackmerc]

Sounds like converter shudder. Drain & refill fluid.

[Louisianimal]

Exact same thing here

[8UWITH6]

Shudder fix from napa. Red tube 4 oz or so. Instantly takes care of this issue on Fords IF it is the torque converter causing your particular issue. For 7 bux its worth a try.

[BAD MERC]

I'd also park on level ground and rock the car back and forth in park. Watch the upper rear control arm bushings for slack.

[HotRaud90]

Sounds like converter shudder. Drain & refill fluid.

Seeing that I've done a couple of pan drop and fills in the past 12k mi or so, do you think I could get by doing a pan drop and fill every oil change until I've got practically all fresh fluid in the system? Unless I'm missin somethin here, that seems better than payin $140-$150 to get a tranny flush and fill.


Shudder fix from napa. Red tube 4 oz or so. Instantly takes care of this issue on Fords IF it is the torque converter causing your particular issue. For 7 bux its worth a try.

I was thinkin about takin a look at this. Maybe I'll use it as a temporary fix until I can get more fresh fluid in the system. I also saw Lube Gard which is supposed to be a more long term solution to tranny and shudder problems.

[HotRaud90]

Also, is it possible that the O/D band/clutches are goin bad in the tranny? Reason I ask is that I only really experience the problem while in O/D.

[Shornaday]

My 03 Grand Marquis did the same thing. Had the local ford garage change the fluid, but that didn't work. Next changed the Torque Convertor, that didn't work. However the Torque Convertor they put in was bad so they changed it again. Finally all was good.

[8UWITH6]

I have "fixed" or I guess I should say seen real world results on a 01 Harley F150 with 149k miles and an 08 Ford Edge with 230k miles. It eliminated the torque converter shudder those customers immediately. And they understand it is not a repair just allowing them to go farther with what they have.

http://www.napaonline.com/p/BK_7652969

[HotRaud90]

I think I might look into Ford Friction Modifier as well. Seems to be recommended by Ford techs and such. Seen multiple instances where people fixed the problem with some friction modifier. I might use some lubegard or shudder fix for now, then put in the recommended friction modifier once I get the full system drained and filled.

I'm wondering if it would be ok to do pan drop and fills until I've swapped in practically all new fluid.

[HotRaud90]

Although I did add a bottle of Ford friction modifier and noticed a difference in the right direction, I am still getting the shudder from the tranny. While not as bad as bad as before, still there. Probably fixed 25% of the problem by what the seat of my pants is tellin me.

What I've found is that the problem only exists in O/D AFTER the TC locks up. Could this be my TC going bad? I've thought about changing all the trans fluid in the system to see if that helps, but the last couple times I've done a drain and fill while dropping the pan the fluid has been a nice tone of red with no indication of burning or bad deterioration. In the 30k mi I've owned it, I've dropped the pan and put in new fluid twice (Castrol Mercon V). I'm hesitant to throw in 13-14 quarts of new fluid and that not fix the problem. Any way to really test to see if a bad TC is the problem for sure?

[Marauderjack]

FORD Friction Modifier works well for TC shudder....may take a 100 miles or so and a second bottle won't hurt......been doing this for years especially in the late 90's!!:beer:

I always add it to my Marauder when I replace the fluid in the pan every 30K miles or so......never a hint of shudder and I have over 265K miles on the OEM TC!!:bows::D

[HotRaud90]

It has been close to about 1k mi since I added the modifier. No complete resolution yet, although the FM did help slightly.