Kelvin,
U are right that you do not need a overhaul. if it have not start to effect too much on the driving and not slipping, then a "flush" is enough to fix it. did that to all my BMWs and non ..
There is only 1 place that i know who really knows how to do it. Cheh Auto at ulu Kelang. near melawati. the owner also BMW enthusiast drives a M5 E39
Call Roy, 012-2238545. He is not the workshop guy buy supplier of Torco oils. A true blood car enthusiast and willing to be there to guide you through the whole process of flushing.
rough flushing cost.
Lubegard ATF flush 1 bottle - about 100
12 litres of SPII ATF = about 250
12 bottles of Torco ATF = 12 x 80 = 960
Filter kit ard 150
Labour = ard 200.
Time ard 3-4 hours.
the price i indicated is a little on high side. i did mine around 1200 without the filter change 1 year ago.
the lubegard flush is amazing. i cannot imagine that much dirt and build up in my fluids even though i change every 40K.
result is a biting lockup without any slip .. like new. the flush process clears off all the carbon in the valve body and torque convertor.
do call me if u need help.. 012-7177082