Hi i have an old michigan 85A which seems to power forward but wont always go in reverse. I have checked the convert pump pressure and working fine, checked all the ports on the control valves on the top of the tranny, the drive shaft between the converter and tranny is working fine. All the oil levels are correct and fluid shift between hydraulic and trans is not occuring, have taken the top cover off trans and blown all ports out can hear clutches engage all bar reverse so took the bottom cover off screen looks clean and able to move what i think is reverse gear from parts diagrams from minpar. Will have to pull clutch covers off as i can see it will be the double clutch cover? Does any one know what sort of pressure the clutch should have from those 10 springs. Will investigate clutch plates discs today for wear?
What are you getting for reverse clutch pressure? Depending on what transmission that you have. T-75A idle with hot oil all clutches should read160-200 PSI R300 should read 180-200 PSI 2420 trans 180-220 PSI. Could be a seal ring on the clutch shaft or a crack in the shaft between the oil passages. The 10 springs are seperator springs to push the clutch piston back when it is disengaged, 50 to 60 Lbs total. make sure that they all go back in the same location.
Problem found I assume oldseabee thanks for the info. Clutch pressures seem all right now, after dismantling the reverse clutch i found an old O ring peice stuck in the release ball in the clutch plate housing hence why it would work sometime and not others i suppose. All the seals seem to be doing there job. Ihave blown the ports out with air to ensure no further contaminants are in the system and will put the machine back together today and see how it goes. Everything else seems to be running as it should be.