JD 7520 Trans Problems Update

Deere7520

New User
1975 4wd 7520. I changed the trans oil in the tractor and filter and the old oil smelled burnt and was almost water like. There wern't any metal filings or other junk in it. It still heats up in low range. I drove it less then 1 mile empty and it was hot. I am almost sure the heat is coming from the transmission and not the torque converter. The axle housings weren't very hot until where they connect to the trans, and the rockshaft piston area wasn't very hot this time. I could hold my hand on the torque converter but not the transmission. There is a hydraulic chattering noise that I could hear. I plan on letting it cool overnight and trying it in high range tomorrow. It still seems weird that the tractor won't power itself in 8th gear it will just stall it right away. I got it into 8th one time going down a hill but then on the flats the rpm will just fall off and slow down until I have to shift down. If anyone has any ideas let me know.
Thanks
 
Well for one thing there is no torq converter,,Now about the stalling in 8th,,is it 8th only?? How about 7th or 5th ?, some thing is differently gaulding ,,be careful taking it out,,it may not come back!!Try 7th and 5th to see if it binds up,,normally it's on the top shaft..I fear that your gonna need to take it down and inspect thing till you find the trouble,,and it should be obvious..The lube pump could be failing to start all this...
 
It's hard for me to say that it is running fine in the other gears since I'm not really used to this tractor. I haven't owned it very long and finally have a chance to use it. It is very strong in low gears 6&8 seem to be the worst but 5&7 seem fine. I guess I'm still thinking cars to call it a torque converter instead of divider. I guess I'll have to take the cover off and take a look inside. Just a curiosity question if this trans rear end would go poof, is there anyway to fit a 8430 or 8440 series quad range to this?
Thanks
 

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