Shudder I'm reverse only.
 

I have a 2003 f150 4.6 with the Triton v8. When I put it in reverse it shudders like crazy when I got the gas, it doesn't shudder when I let it idle while in reverse. Also I put it in 4wd high and it still did it in reverse, when I put it in 4 wd low it did not shudder at all? I have already replaced tranny fluid and filter and topped off the rear differential fluid, any ideas because I am stumped.

You'll need to get your transmission serviced.

It was just in a shop and they can't seem to figure it out, I recently bought it and it has an extended warranty so they are going to fix it but they don't know what the issue is. It just had it's tranny fluid and filter changed today and the topped off differential fluid after pulling the cover off the pumpkin to inspect it

It's going to take more than a transmission flush and a filter. That is likely the clutch pack going out.

thank you, I will bring that up to the dealer. I hope that is it because I'm tired of searching this issue