Hey Folks

I picked this '08 F250 5.4 4x4 auto trans extended cab short bed 46k miles about a month ago. It's stock except for a K&N air filter set up and Flowmaster after cats exhaust. It's a sweet running machine. What I'm finding though is that sometimes when I shift to reverse (the truck is not rolling of course) it seems to slam into gear. Othertimes it shifts smoothly, as I would expect. I've tried stuff like shifting it with my foot on or off the brake, waiting for the engine to heat up to normal temp before moving, but still it sometimes slams into gear (reverse only) The idle is at 700 rpm or so. This could be nothing but it seems like it's taking a beating.

Dave

This is my first post...

 

Could it be the clunk in the driveshaft? Need to grease the slip yoke?

 

I'd think the slip joint also. My truck shifts into reverse harder than my work van. I dont shift until the RPM's are very very low. In the van I can hit N between and roll a few inches, stop then shift to R. The truck's shifting is much too tight for me to do that. Different years and different motor/trans so .

 

slip joint or u-joint at the rear diff

 

My 05 has done this since new, but it's only when it's cold and idling high. Shift it into reverse and it feels like it's going to spit the drive shaft right out from under it. Once it warms up a little and the idle comes down, it doesn't do it. I've heard this from several other 05 and newer gasser owners as well.

 

my 08 does it as well once in a while. has no pattern to it, truck could be hot or cold.
not a slip joint or u joint problem with mine...seems more like the trans is getting full line pressure shifting into reverse. never bothered me enough to bring it into the dealer though as intermittent problems can be hard to solve, truck would probably go in the front door and right out the back door!