on a 99 5.4l v8 with 200k, ive reached a really odd issue with my truck.

when accelerating from a standstill, i feel a vibration all the way to my rear axle similar to a shutter and than goes, but if i was to floor it, it goes away.

also when the truck shifts into overdrive and if i let the rpms drop say from 50 down to 45 and slowly add throttle, the truck jerks a bit wanting to go but demands to stay in overdrive instead of shifting unless i get on the gas.

(this issue only happens at low rpms)

my questions is, what could be causing this. torque converter slipping? bad fuel pump? spark plugs? coil pack?...

where would you begin. (i had the tranny fluid changed along with the filter about 7 thousand miles ago).

currently, Ive got the negative battery disconnected to go into relearn mode. if thats going to fix anything.. (doubt it)

 

i had this issue twice once was it needed a tune up ( new plug wires and plugs) and the second time was the transfluid. sisne you said u changed that id look into possible a tune up. just a thought im sure someone else will chime in with more help.

 

thank you for the insight, hopefully more people will be able to help :/

it could be in need of a tune up. i'm just hoping that its nothing too too major such as my torque converter/ tranny since well. i cant afford a new car. economy's hard so any insight will be greatly appreciated.

 

Checked the U-joints ?

 

whats the best way to check them? should i also grease the slip yoke?

 

With the brakes on shift from R to D - listen for a clunk, Or crawl under and check for play, Truck on level ground and rock back and forth. And the slip yoke wouldn't hurt to be greased from time to time - But a slight miss can cause a very frustrating shudder during acceleration. If its been a while a tune-up might do good.

 

from reverse to drive, yes there is a clunk. more like a slam. my question is would that cause the shutter i feel in overdrive too while im putting a load on my truck? or would that only cause the issue i feel from a standstill.

edit: the clunk and slam starts happening once the truck is warmed up and went on a drive.

 

Bad U-Joints

 

So, the issue I feel with my transmission when its in overdrive and there's a load on it is caused by my bad u joints?

 

the shutter actually goes away once its driven for quite a while.