The 5k shift point is your kick down solenoid. Either your kickdown switch under the accelerator pedal is stuck or the solenoid in the tranny is stuck.

Unplug the switch under the pedal first and see if the symptom goes away.

If that does not work, try (while driving) engaging the kickdown switch a few time and see if energizing the solenoid will unstick it.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)