during a cross country trip in my '77 245, my transmission(m-46) had been slowly leaking without my knowledge. At a home of a relative when I was just 400 miles away, it started making some very subtle, almost harmonic noises which I brushed off at first. Then came a smell of perhaps burning ATF, and I pulled off to see what was the matter. Fortunately I had my tubing I use to fill the transmission, as it was completely dry. At that point, I was unable to use my reverse gear. The car would almost move, you could feel it pull, but then would slip with a horrible grinding. Also at that point, in forward gears, if I attempted to use the engine for braking, the output would turn faster than the input, and the engine would have to 'spin up' to the level of the wheels when the gas was reapplied before it would add any acceleration. I am 90% sure the problem is in the overdrive and not the transmission. The reverse problem comes and goes, but the forward gear problem persists. I don't know much about the internal workings of the overdrive, but suspect the unidirectional clutch. Any thoughts on repair vs replacement vs rebuild (of overdrive) would be appreciated.

wrc