My wifes 97 T Bird with v8 auto shudders under acceleration. I'm at a loss. Only does it during an easy take off and sometimes while increasing speeding for passing. My old 77 F150 just keeps on trucking though. Help appreciated.

 

From what I have read, that is a typical symptom of the torque converter lockup clutch slipping, aka Torque Shudder.

When you are in cruise mode the converter is locked and doesn't have a lot of stress on it so it doesn't slip. When acclerating hard or decelerating, I read, the converter unlocks so no shudder. But when the clutch is locked and under light acceleration, it will shudder. My F250 did this at about 40 to 60 mph under light acceleration, felt like driving on grooved roads.

The shudder inder light acceleration was my symptom along with intermittant hard shifting.

Usually requires a new converter and probably a rebuild of the tranny. Sometimes can be cured with a fluid change. Sometimes the bandaid additives will fix it for awhile.

The first step is to drop the pan and inspect the fluid for color and smell and see what particles are in the bottom of the pan.

Fluid should be red to dark red. Not black, brown or pink. Should have a nice chemically smell, not a burned smell. The pan should have maybe a teaspoon of pepper like flakes(clutch material) and maybe a light fuzz coat on the magnet(usually at the bottom of the pan and looks like a donut or square.) If you see metal chunks say bigger than rice and more than just a 2 or 3, then you have some heavy metal wear somewhere.

Like I said sometimes just dropping the pan and fluid change, including the converter can sometimes "fix" this problem.

If torque shudder continues, eventually you will need a rebuild since it is a symptom of slippage which creates heat which is bad for auto trannies.

Good Luck,

Jim Henderson

 

Thanks Jim. Will pull the pan this week and check it out. Had car since new and only has 93 k on it. Alan