car juddered after spark plugs changed

[saifoz]

as I slowly accelerate from the 4gear to 5 gear and RPM is about 2000 to 3000 I felt a judder in the transmission. this has never happened before but i felt it when i got the spark plugs changed

any clues what happend

[abrahim]

Check the spark plugs wires, it may not be properly fixed. Just push all wires by yourself hard enough inside the spark plug mount and check.