I have a 1994 f150 with 300 6cyl and automatic.when under load going up hill or just accelerating a little i get this horrible shudder.does this sound like my torque converter.

 

Might want to look into the coil packs, unless you have a distributor and plug wires. I've had that prpblem and it ended up being one of my coil packs. It shuttered really bad while under a load.

 

try changing the plugs

 

Does this happen when you power brake the truck? If so then it would be a misfire and you're on the right track. If not, it sounds like a u-joint.

 

hmm I havent ever had this issue but what about when you hit a hard bump does your headlights kick off then back on real quick? Thats the issue I have

 

I replaced coil,plugs,wires,cap and rotor,fuel filter.As a matter of fact i replaced the wires twice with no change.

 

This sounds like the classic torque converter slipping. Change your fluid asap and use Mercon V. This is a very common problem with that vintage transmission. I had the same problem with my 95 Mark VIII lincoln that used the 4R700W and changing the fluid fixed it and the problem did not reoccur in the next 70k miles before trading.

Your vintage truck should have the torque converter drain plug, so you can drain everything yourself.

 

Definitely flush the converter. You may want to/need to replace the harmonic balancer as it will cause the same vibration at certain RPM ranges.