I have just begun experiencing some jumping in my 99 F150 4x4 4.6L. Normally this happens when I am at a low rpm with the automatic transmission shifting from 2nd to third (going up a hill). I have not experienced this with a higher rpm. I also hear a click underneath the truck when I am slowing down from about 25-30mph to a stop. Could this be a sensor??? I have never towed anything with this truck and it has about 45,000 mi. Thank you for your help.

 

Don't know if this helps, but have you checked your fluid level lately?

 

Yes it's fine. Thank you tho.

 

my 1997 started doing the same thing (slight chattering vibration). it was noticed the most when going up a hill or bridge just before downshift. i took mine to the local atlas transmission shop and had the transmission serviced including all the fluid and filter. the problem went away. about a $70.00 fix, not bad for the normal repair prices of today.

i hope this will help, it surely did for mine,

mike