I purchased a 96 F-250 5spd back in July with 80K on it. It was a buisness truck that did more sitting than anything else. It had all the service done on it and even had the clutch changed to a LUK. It runs nice on the highway and gets 16 with straight diesel and 18 when Diesel Kleen(gray) is added. My question is about a strange vibe around 1200rpm. When i'm trolling thru a parking lot in third and the RPMs get over 1000. You can see the stick swinging back and forth pretty bad and If I stay at a consistant rpm the truck will start to shake with the vibration. Is this normal? I understand that diesel trucks work on a whole different concept and their is some vibration.

 

welsome to the PSD ranks. sounds like it might be a manual trans specific issue maybe something normal with the clutch conversion. but i don't have any experience with them so hopefully somebody with the clutch conversion can help you out.

 

Definitely not normal. What kind of shape is the tranny mount in?

 

Also, our trucks with the 5sp have a tranny counter balance that hangs down below the cross member. If that's missing, you will have a vibe.

 

I know the weight is there. I'll have to check the mounts this weekend.