87 190DT Transmission

[jgauto]

My 87 190 Turbo Diesel appears to be leaking transmission fluid from the front and rear seals. The vehicle has 172,000 miles on it and is still running strong. The fluid doesn't have any odor and it goes in "R" and "D" instantly. It shifts fairly smoothly. Only in stop-n-go traffic it shifts a little harshly. I inquired at my shop about fixing the leaks and they said it would cost about $600 in labor just to remove the transmission. The shop mentioned that it probably wasn't worth it since the transmission was probably going to go out soon. Is this true? I know of and individual that got close to 400,000 on the original before a rebuild.