Mine was an 88 or 89. It had the cummins, and the unable to see transmission display. It had a 14 foot MB, which was a little too big for the machine. It was my daily driver from 1998, to 2012. I think it had like 28000 hours on it. It used to put oil out the vent for the transmission when driving at full speed. They put a tank on the back of the cab, ran the vent line to the bottom of it, and put the vent cap on top. It would catch the oil, and allow it to drain back when you slowed down or stopped. It never let me down. I like my 2011 Volvo. Same MB system, a bit more plastic for wear parts, but it is the king of codes. I farted today, and it gave me a transmission code. If you look under the front of the circle gear, there are 2 gears that turn the circle with the cranks and pistons. In between the 2 is a thin gear for timing. If you never grease anything else on the machine, keep that greased up. If it gets worn. The bearing, not the gear. It will f up your timing, and the circle will start jamming