'93 960 overdrive has started to cycle on/off randomly

Around 45 to 50 mph, under constant load, the transmission cannot seem to
decide which gear to use. The overdrive randomly engages and disengages
every couple of seconds. This happens with the transmission in both economy
mode and sport mode. The car is a '93 960 with 175k miles. The fluid level
is correct. Is anyone familiar with this problem?

 

Could be the torque converter... sound like what my friends Oldsmobile was
doing.

 

As your 960 has covered 175,000 miles has it ever had the ATF changed? In UK
my recommendation has been to flush/replace the fully synthetic ATF every
100,000 miles so that the insides can be refreshed and the filter cleaned
out. There is no overdrive as such. The AW30-40 gearbox is four-speed with
lock-up above 55-58 mph. This could be caused by the W-S-E switching and
connections, or the gear position switch under the car on the gearbox
linkage. Check all electrical connections to the box and the two switches at
same time as carrying out a flush/replace & filter clean. Once that has been
done allow a couple hundred miles for all bad symptoms to clear before
heaving sigh of relief.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).