1993 500sel/s500

123,331

the only records i have is for engine oil changes, i dont have any records on work done to the transmission

i bought the car in july 2005 with +121,000 miles this problem occured right after the odometer tunrned to 123,000 on the freeway. i cant explian exactly what happened at that time because my brother was drivng it when this first happened. but i can say what i have experinced.

the car seems to have a transmission problem

when im in the freeway my gear dosent seem to want to change when im doing about 80 mph and rpm is around 4000, which seems pretty high to me.

some other times when driving in the freeway, im not sure at exactly what rpm level but my rpm jumps up from one low level to a high level back down to what it was. i dont know if this is called a transmission slipiage.

i was told by a local oil lube shop that (does not specalize it mercedes) i just need to change my transmission filter and do a flush.

does anyone know if there is a possibility that it might be the transmission filter or anything else like some knind of sensor? im just tring to avoid even thinking about a trip to the dealer to replace this transmision.

im not to sure if this is my 3rd or 4th gear or passing gear.

if there is any other info that is needed to determine this problem let me know.

any info or suggestions would be helpful

thanks in advance