Question

Most probable cause for rough shift into reverse 740il with 5hp30? so far I have cleaned the range switch, rebuilt the valve body using the zf 5hp30vbk upgrade kit, new oil and filter and substituted a spare transmission module. have found one case where it will shift properly into reverse----start cold (60 degrees in Arizona) drive a couple miles turn engine off, restart 5 minutes later and it will rather consistently give a soft smooth shift THE FIRST TIME TRIED ,BUT ROUGH ON ANY IMMEDIATE ATTEMPTS AFTER THE FIRST !!! One of my first thoughts was a sticking accumulator but when I disassembled the valve body it was clean and all of the spools and accumulators and bores were as new, no signs of damage anywhere.There is one thing that I am not sure is significant but I will describe it in the hope that it has been confirmed by experience that it can contribute to this fault----with key on, but not running you can read the shift position on the dash for each lever position,and they are all correct. If you move the lever from either side of R very slowly toward R THERE WILL BE A VERY SMALL AMOUNT OF TRAVEL WHERE THE SIGNAL WILL DROP OUT (NO SHIFT POSITION READING).If this is not normal operation of a range switch then perhaps the computer interperts the drop out as a signal to revert to the emergency mode in which case a rough reverse shift is to be expected !!Sure hope some expert has direct experience with this. I am getting worn out thinking about it. THANKS FOR YOUR HELP

Edited by XXXXXXX on 3/23/2008 at 1:34 AM