Hello, this is my first post and I have a question.(I tried searching the forums first but, no luck)

I have a 2004 F250 XLT 5.4L FX4 that shifts hard and has a clunk when upshifting from 2 to 3; with the OD on and off. The problem shows up during normal acceleration from a stop. It shifts fine from first to second. If I let up on the gas as I am approaching 35-40 mph (in a 35-40mph speed zone) and there is no load the clunk/hard shift happens. When I am towing my dump trailer or heavy acceleration like entering the freeway that hard shift does not happen. Any help would be appreciated. Thanks in advance.

Best reagrds,
Jon

 

The clunk can be normal if you're transmission is mant for heavy towing. The clutch plates in an automatic trans. are closer in a good trans. to keep from wearing out too fast. Unfortunately until they have some miles on the shifting will act the same with no load. Either that or you could have a pressure problem where a leak occurs under normal conditions but doesn't affect anything when under load. Either way it's usually not substantial unless it worsens. The clutch plates should only get better though. If a pressure leak worsens - get to a shop early (especially if it's warranteed).