RetroMower 349 #1 Posted November 6, 2019 Finally got time to put my tranny back together yesterday and it went really well. New needle bearings and seals went in as well as the new main bearings from the gracious mr Lowell. I dont have a press and i really didn't want to hammer them in so I used a trick of freezing them. Went in snug with a few persuasive taps. The gasket for the case I ordered was off though. It seemed to be smalll in all directions. When put over the two dowels all the bolt holes were slightly off. I figured being a thin cardboard gasket it had shrunk over time and a little water mist fixed that. It swelled up and fit perfectly. Now its all back together and I'm in need of some reassurance. The lable on my tractor says it calles for 10w30. I have an automotive background and thats an odd transmission oil. After looking at some older threads this does seem to be the case for my 90-1136. Some older models used ATF fluid. My question is the capacity and does the hydro unit AND the transaxle share the same fluid? 1 Share this post Link to post Share on other sites
Pullstart 63,096 #2 Posted November 6, 2019 Here is a link where @pfrederi told me the whole system uses 5 qts. If it had ATF, use ATF. If it had 10W30, use 10W30. Both types were used in the transmissions (hydro and transaxle are one unit), so it’s advised to stick with whatever was there. 3 Share this post Link to post Share on other sites
JoeM 7,874 #3 Posted November 6, 2019 10W30 is fine it is more of a hydraulic oil system and the motor will lubricate those rear end gears just fine. I lean toward synthetic for better heat dissipation but it is not necessary. I get the full synthetic at Rural King, $15 for 5 qts. 1 Share this post Link to post Share on other sites
RetroMower 349 #4 Posted November 6, 2019 Thanks, 5 qts it is. Now obviously the transaxle gets filled through the dipstick but Im guessing the top plug on the pump should be removed and some oil added there for priming and to prevent dry start up and damage Share this post Link to post Share on other sites
oliver2-44 9,861 #5 Posted November 6, 2019 The system will not drain completely and once you pull that plug more could drain and it will let air in system. I've done 3 oil changes on my C-160 Sundstrand and have been lucky and have not had to bleed it. I drain the transaxle, then pull the filter and immediately put the new filter on. I prefill my filter before I put it on, which makes installing it a bit messy. I put the rear end on jack stands when I first start it and work the motion control lever forwards and backwards. My thought is with it lifted up the pump is having to do minimal work so its possible easier for it to prime. If it were dry for a moment, then its not working hard, and the internal surfaces are at least coated with a film of oil from prior operation. If the rear wheel don't start turning in a couple of forward/backward movements of the motion lever, then I would consider priming it. I'm interested to hear what other say/do! 1 Share this post Link to post Share on other sites
RetroMower 349 #6 Posted November 6, 2019 The entire system is bone dry. When I separated the hydro unit from the transaxle, I drained the transaxle and I removed the plug from the bottom of the pump where it bolts to the transaxle. Whatever was left inside likey drained out on my bench when I had it apart and was cleaning decades of goo and grass off the fins. Share this post Link to post Share on other sites
oliver2-44 9,861 #7 Posted November 6, 2019 Since it's bone dry, Yes I would prime it. @daveoman1966 can you share any advice on priming and bleeding air out of this sundstrand if needed.. Share this post Link to post Share on other sites
