i have a p71 2006 and sometimes at even speed around 80km/h my car starts to stutter and jump up and down 200rpm if i let go of that gas or give it more throttle it works fine again this happens once every 2days.This also happons almost everytime i go of the throttle completly and coast arond 70-90km/h and when i go on the throttle again the car revs around 200rpms before it takes of.
is it my transmisson? torque converter? or something else?

the car dosen't throw any codes. i have done a pandrop and the oil looks good.

my personal guess is the torque converter since the car dosent do it in higher speed.

Welcome to the forum.I am sure some with more experience than me will chime in eventually.

What happens if you manually turn the O/D off? Any change in 3rd gear only?

With that small of a RPM drop, it sounds like the torque converter lock-up clutch is going in and out of engagement, or slipping very badly.

Agree w/TheShadow. It does in fact sound like TCC shudder. The fix is to change the transmission fluid, taking care to use only an approved Mercon V product.

its the same if i have the od off or on

i will change the transmission fluid this weekend or maybe next weekend . i will post if it helps or not.

Yup, TCC shudder...follow RF_Overlord's advice.

Be advised that depending on how depleted the old fluid is, the effect may not go away immediately. It can sometimes take a short bit of driving.

okay thanks for the advice

I have a 2004 and 2 months back I had similar issues but it would occur every few months and I had weird idle issues even though I did everything I could to resolve the issue from the intake manifold up including buying new various sensors.

Not trying to scare you but my transmission finally gave out at 240k so I got a low mileage used transmission installed and a new torque converter and all the idle issues and engine stumbleing are now gone.

My 1999 had the shudder until I changed the fluid and filter based on advice from this forum. Don't forget a new filter. Get the correct filter and install it by the book. Mercon V fluid. The pan gasket was reusable but since it was twenty years old I replaced it anyway. Reusable doesn't mean forever.

The shudder was most noticeable in high gear while lightly accelerating up a slightly rising hill. Car fully warmed-up.

I thought that I had TC Shudder for a long time. Happened only when at 40, cruising and then going up an incline. Even after doing the JMod, it never went away. ForScan didn’t show any misfires either. So I figured I would live with it until it just breaks completely.

While doing plugs and coils as PM, that literally fixed the issue.. and my spark plugs were really really toast..

Just saying. My 2 cents.

hey i just wanted to let you guys know that i flushed my tranny just over a week ago and its so much better now my transmission has never shifted gears so smoothly before. The car still shudders sometimes but not as often and its definetly not as bad as it was before. So now its perfectly driveable and not as annoying as it wa before.

These hold 13+ quarts, so they need at least 10 fresh quarts for best results.

Al