Hi,
I have a 1999 F150 Lariat 5.4 42k
I have a clink or thump when I take my foot of the gas the trans tries to drop to 3rd. I'm travelling at 46mph and 1200-1400 rpm.

It makes a noise as if I was trying to start off in 3rd of a manual
transmission. Thump thump.
Dealer changed fluid etc...... still does it.

ps. the service engine light is on. but may have no connection



Help

 

I have the same thing in my 97 with 70K miles. When I cruise about 42-43 mph under part throttle, it clunks and feels like somebody is hitting the truck from behind. If I try to hold the speed, it will do it repeatedly every second or so in no regular pattern. If I increase speed or reduce speed, it will settle into gear. Also it may be in my head, but I think I feel more vibrations in other gears as well.

 

It's the same thing... I had the transmission flushed and
filled micron v. It still does it but not as bad. I also get the feeling that it's not riding right. I had an Expedition do the same thing. But it was leased and I dumped it.

 

greg66,

I changed the egr pressure sensor valve.
It was quite easy... this allowed the engine to rev a little higher
at shift points and.... so far no thumping
The sensor was $62.00

 

Thanks for the reply. I've gotten a lot of help from dirtyd0g (on this forum I believe) and it looks like my problem is a converter clutch issue. I had flushed the fluid, drained the torque converter, and still had the problem but not as bad - just as you said. After explaining this to dirtyd0g he sent me some instructions on modding two holes in the valve body, plus I have a new torque converter and some 1-2 accumulator springs to install... I hope to try all of it this weekend.