Own 2008 3500 cummins diesel, changed transmission fluid and filters 2 weeks ago, now in the mornings temp. around freezing, when put in gear truck takes off normal and then lunges forward like grabbing 2nd gear. Backing up one morning put in reverse truck began to roll back it locked into gear and acted like it would if you dropped the clutch on a standard and then killed the motor. Have also had problems with floating between 1st and 2nd gear, but all happens in the morning and is fine after truck after truck warms up. Any ideas on problem?

 

Welcome to the forum!

Are you sure that the filters are seated properly? This causes many issues on the gas trucks.

 

Tightened the twist on filter 3/4 turn past snug. Flat filter tube slides into rubber bushing, one screw holds it inplace. Fluid is reading maybe 1/4 of a quart low.

 

Also pulled codes this morning and came up with PO732

 

The o-ring seal is usually the one that causes problems on the 545RFE. Not sure about your trans. Sounds like the same set-up, though.

That code is thrown when the PCM thinks that the transmission is slipping because the input shaft speed and output shaft speed differences are of tolerance to the high side.
Could be from the filter sucking air, or an internal problem.