Bad Tranny Fluid???

[BrowneBlue]

I don't want to drag you through this topic again, but I got to thinking more about it and talking to a guy today that has had some experience with this. As you may recall I have a 1967 D200 with 318 and NP435. It grinds some sometimes when I shift. I've done the exterior homework: New Clutch Master Cyl, New Slave Cyl, New line, adjusted and bled. When it's cold out (below 20) before it warms up it will shift smoother. After a mile or two it will start to grind again occasionally. I know it has oil, but is the oil bad or the wrong kind? The guy I was talking to today suggested that the oil could break down and be bad thus allowing it to grind like this. Does that sound possible? I'm about to take it to a shop for a new clutch so I want to do one more bit of homework first. What oil should I be putting in it? Thanks,Scott

[dakotadave]

i put 90W gear oil in mine.

[EGroscup]

Bad fluid could be a contributer. Had the same problem on a guys diesel bunny truck. (VW Rabbit). The manual said that the transaxle had a factory lifetime fill and never needed to be changed. 100,000 miles later it got very hard to shift when warm. New oil was the fix. Go figure. Erik

[nfury8]

I would change the fluid just to play it safe. Couple quarts of 90w will not cost ya much,
and it is just good maintenance. You might also throw in a bottle of STP oil treatment.
My dad swears by the stuff on his old 4 speeds, and it did quiet down my transfer case a bit.