clueless 2,974 #1 Posted July 8, 2016 Pick up a 1977 B80 8sp the other day, drove to far and paid to much, but down here that the way it is. Anyway runs and drives good, I'm in the posses of cleaning it and replacing a few things. Plan to drain trans and put new fluid in, read that some of you run some diesel through it first, diesel oil or fuel? Chris. 2 Share this post Link to post Share on other sites
JoeM 7,871 #2 Posted July 8, 2016 I use kerosene, 3 quarts, running for 10 minutes on stands. drain it out while all the dirt is suspended. I have had to run through twice. don't be surprised if you find a seal or two leaking. I raise the front wheels 18inchs or so to get a good drain. I've done this twice with no issues. 4 Share this post Link to post Share on other sites
rmaynard 15,419 #3 Posted July 8, 2016 (edited) The 1977 B80 is a great machine. Diesel fuel or kerosene will work well to flush the transmission. First, remove the plug in the bottom of the transmission. It is a 1/4" allen-head plug. The transmission holds 2qts. You will have to lift the front of the tractor to get all the oil out (hump in middle of case). After flushing, refill with a good gear lube. Get a new boot for the shifter to keep water out in the future. I add oil through the shifter hole. It's faster that way. Walmart house brand 80/90 or 85/140 will work fine. Edited July 8, 2016 by rmaynard 5 Share this post Link to post Share on other sites
Terry M-(Moderator) 2,175 #4 Posted July 8, 2016 Well said Bob.....Though be aware when flushing with kerosene as it could leak out the seals . I had this happen on a 65 lawn ranger. I was cleaning up...but when I drained the kerosene and refilled with Gear lube , all was well again with no signs of leakage. Maybe Lucky? Just my 2 cents 3 Share this post Link to post Share on other sites
KC9KAS 4,741 #5 Posted July 8, 2016 I had to drain & re-fill (with Kerosene) 3 times on a C-120 recently to get it cleaned up! 1 Share this post Link to post Share on other sites
Spike957 0 #6 Posted July 19, 2016 Is it OK to use this diesel/kerosene method also on a hydrostatic such as on a 516H? Share this post Link to post Share on other sites
JoeM 7,871 #7 Posted July 19, 2016 I use automatic trans fluid in the hydro's. I think the kero doesn't have good enough lubrication for the hydraulic pump and motor. Share this post Link to post Share on other sites
Racinbob 11,035 #8 Posted July 19, 2016 I believe @Spike957 is talking about flushing a hydro with diesel fuel. I'm not up on hydros but something it telling me that it wouldn't be a good idea. I'm curious if others here have done that. 1 Share this post Link to post Share on other sites
Spike957 0 #9 Posted July 19, 2016 (edited) The atf sounds like a better idea. So what fluid did the hydrostatics have in them from the factory… Atf? 80/90? 10/30? Edited July 19, 2016 by Spike957 Spell checker mistake Share this post Link to post Share on other sites
pfrederi 17,643 #10 Posted July 19, 2016 Do not flush hydros with Kerosene. Way to thin. What fluid was in there?? Older ones had AtF (cherry Red) Later had Motor Oili 10w-30 or 10w-40 (tan). Both work. If you want to switch over you have to flush 2-3 times with the new stuff you want to use. Not worth it in my book. i change out and stick with what ever was in there. (they all work OK) Share this post Link to post Share on other sites
Spike957 0 #11 Posted July 19, 2016 Thanks- it looks like it is the 10w30. And although it's quite low on the dipstick, it's surprisingly clean! Share this post Link to post Share on other sites
Jerry77 1,218 #12 Posted July 20, 2016 Spike - I have a 516H and everything I have been reading about it says to use 20w motor oil.....tractor supply is the only place I know of that carries straight 20w... I'm sure some of the more knowledgeable guys will have the correct info....welcome to red square... Share this post Link to post Share on other sites
