Transmission shudder

my 2002 F150/4.6L/automatic/ 2 wheel drive

transmision shudders when upshifting. Does so at approx. 1400 rpm and 2100rpm.

What is the smartest way to solve this malfunction? Thank you for any consideration of my question.

Does it shudder on all shifts? Is it likely that the shudder is occuring with the torque converter lockup? Post the answers and how many miles are on this transmission.

Also look at the engine and transmission mounts to see if they are intact. Check out the universal joints because a seized joint will cause a shudder.

If this problem is pretty consistant, i.e. you can demonstrate it to someone else, run the truck by a transmission technician. Have him/her ride with you while you demonstrate the shudder. He should scan the computer for any codes; do a line pressure check while the truck is driving and the shudder is present; and maybe do a stall test in forward and reverse.

With his expertese, he can give you options.

Hope that helps. Post back with your progress.

Hello Researcher, Thank you for your time and thoughts. Shudder may come from converter but that is an educated guess made by a friendly mechanic.
There are no codes per my local indi trans man. Vehicle has 93,652 miles at this moment. I ordered it new = 1 owner.
As per your suggestions I’ll get it on a rack & chk. the mounts as well as the universal. Thank you again, kojaks

If the shudder is similar to running over those wake up strips on the side of the highway it’s possible the truck could be suffering from a torque converter shudder. Changing the trans fluid often cures this problem.

It’s a common enough problem that Ford even issued a Technical Service Bulletin about it.

could be low on fluid. if not,change the fluid and filter. maybe add some lucas.

Broken and/or slipping intermediate sprag. (One way clutch) They take a beating. Your trans guy didnt give you any ideas??? Did he drive it yet??
You can check the drive line but usually ‘u’ joint issues are evident at any given time, not just during shifting.

Oh yea, Check with your dealer for any computer updates.


Not Lucas, but maybe Lubeguard MV