Won't go, then does and slams your head into the headrest..(j/k about the last part)

[ecaps]

Specs:
1999 4.6L XLT A4WD


All,

I've got an issue with my Expy, but not sure what to search on to even look for answers. Lately, when I'm stopped on an incline (pavement) or in 4-Hi/Lo when creeping up a hill (offroad/dirt/mud/etc..) the truck will seem to disengage the driveline and act as though its in neutral. The engine RPMs increase and then a few seconds later it has always "engage". It's especially noticeable on pavement because it seem the tires chirp and it feels like the AWD has kicked in.

Other than that there isn't any shifting problems when driving at highway speed and start/stop through towns.

Just wondering if anyone has had any similar issues? I've also noticed the gear selector is sloppy, not sure if that's related.

FYI: I have done proper maintenance. Transmission fluid, Transfer case fluid, and all u-joints have been changed within the last 2000 miles.

 

[Bowesmobile]

Do you know what your trans. temps are like when this happens? Sounds like something could be heating up and releasing pressure.

 

[ecaps]

Not sure what the trans temp is as I don't have a gauge for it.

However, I don't think it's temperature related since it has happened after it's sat overnight and when I've driven it all day. The only consistent factor I have noticed is it happening if the vehicle is on an incline and I've either come to a complete stop or going < 5mph and climbing an incline.

 

[Copper93]

Is the transmission fluid full and clean? Sounds like it is low on fluid and the incline caused the fluid to flow away from the pickup/filter.

 

[JUST4FUN]

Agree with copper ,trans should be warm and on a flat surface and running in park then check