I inherited grandpas 1650 diesel. After some much needed services she was up and running. How ever 5th and 6th gears would only grind. Would not even slip in with the engine off. I only use it around the place to blade the driveway and such. Well now after 5 years she is down to only 2nd and low reverse. Seems the synchronizers are wearing out. The short question, is there any transmission parts out there or is this a matter of used parts only?