48re overfill ?
 

I had a service done with a new solenoid and fluid put in .....my ? is the service people put in 2-4 qts too much fluid and now I have a qrease line after 2000 miles of driving above the front universal joint under the bed of the truck...Is the tranny slinging out the fluid or is there a seal where the driveshaft goes in or? there are no visible leaks under the truck?

How do you know they put in 2-4qt too much? That's like saying "I drank about a gallon of beer last nite, but I lost track after the 4th pint."

48re overfill
 

It is a stock pan and it's 8-10 inches above the dipstick full mark

Is that running in Park N or Drive? Your output seal is leaking Easy fix but may be caused by overfill! I check in Drive, hot and level ground.

48re overfill
 

I ck it running hot in park (where is the output seal and how hard to fix diy) truck has 227,000 and is time for ujoints 5.9cummins

It's right at the end of the tranny when you pull the driveshaft out that's the seal!

That is the reason it is showing over full. The trans needs to be checked hot, idling, level in NEUTRAL!!!! Read the dip stick instructions.

The front pinion seal leaking is not unusual. Have to mark the nut position, pull the flange to change the seal.