dcairns560 6 #1 Posted July 11, 2021 My tractor is a 1977 D160 Automatic. I used it yesterday moving dirt with the loader for several hours and everything functioned perfectly. Today I backed out of the barn with no issues, then after moving forward several feet, the rear wheels locked up. I was able to back up a few feet and again they locked up. Once it locks up, if I try and push the motion control lever further, it sounds like hydraulic cavitation. I made sure the push valve was closed and tight. I opened the push valve to push it back to the garage, again after a few feet in either direction the wheels lock up. If I jack up the rear end, the wheels spin just fine. The fluid is clean and full. Not sure if my issue is in the transaxle or the pump. Any thoughts? Share this post Link to post Share on other sites
pfrederi 17,739 #2 Posted July 11, 2021 Most likely transaxle if it locks up with the tow valve open. Maybe a broken Differential bolt that is getting jammed under the bull gear. Do not force it as you may crack the transaxle case... Manual will help you click fuzy picture 3 Share this post Link to post Share on other sites
stevasaurus 22,739 #3 Posted July 11, 2021 When you jack up the rear end and turn the wheels...one wheel should spin in the opposite direction. All that tells you is that the gears inside your differential are OK. It does not tell you anything else, because you are not turning the bull gear of the differential itself. So, what Paul is saying is a very possible choice of what is going on. I would take off the guard and drive belt and try turning (by hand) the input pulley counter=clockwise and see what happens then...with the tow valve open and with it closed. If it locks up, you're already on your way to dropping the transaxle to open up. By turning the input pulley by hand, you will not brake anything and you will know that Paul figured it out. 1 Share this post Link to post Share on other sites
pfrederi 17,739 #4 Posted July 11, 2021 15 minutes ago, stevasaurus said: When you jack up the rear end and turn the wheels...one wheel should spin in the opposite direction. All that tells you is that the gears inside your differential are OK. It does not tell you anything else, because you are not turning the bull gear of the differential itself. So, what Paul is saying is a very possible choice of what is going on. I would take off the guard and drive belt and try turning (by hand) the input pulley counter=clockwise and see what happens then...with the tow valve open and with it closed. If it locks up, you're already on your way to dropping the transaxle to open up. By turning the input pulley by hand, you will not brake anything and you will know that Paul figured it out. Steve d160 wouldn't have an input pulley... Also he coould try turning both wheels in eh same direction when jacked up and listen for any strange noise 2 Share this post Link to post Share on other sites
stevasaurus 22,739 #5 Posted July 11, 2021 No input pulley Paul??? Now I know why I try to stay out of "D" Threads...I know nothing about them. 3 Share this post Link to post Share on other sites
pfrederi 17,739 #6 Posted July 11, 2021 5 minutes ago, stevasaurus said: No input pulley Paul??? Now I know why I try to stay out of "D" Threads...I know nothing about them. They are there own "special" breed. 1 Share this post Link to post Share on other sites
daveoman1966 3,751 #7 Posted July 11, 2021 My C-160 Auto had the same 'lock-up' symptoms. Problem was one of the differential bolts worked loose, then got sheared off...locking the the internal gears when the tractor rolled fwd/bkw just a short distance. The issue here is a gear problem...not hyd pump related. HOWEVER...I also bet that the hyd pump and motor have...or have had...steel metal filings...from that broken bolt...get into the soft BRASS machined surfaces causing damage. Inasmuch as you'll need to split the gearbox to repair the diff, it'd be a good time to rehad the ENTIRE hyd system...Pump and Motor. 3 1 Share this post Link to post Share on other sites
Pullstart 62,878 #8 Posted July 12, 2021 If I haven’t already, Sorry about your misfortune. The fellas who have commented here can practically rebuild these transmissions blindfolded with both arms bound behind their backs... they could help you along every step of the way 1 Share this post Link to post Share on other sites
dcairns560 6 #9 Posted July 12, 2021 Thanks for the replies gentlemen. Got the transaxle just about ready to pull out. Hope to have it apart tomorrow and figure out the issue 3 Share this post Link to post Share on other sites
Achto 27,575 #10 Posted July 12, 2021 Following along to see what the out come is. Share this post Link to post Share on other sites
WHX?? 48,815 #11 Posted July 12, 2021 Sounds like Dan is preparing himself for possible D problems. 1 Share this post Link to post Share on other sites
pfrederi 17,739 #12 Posted July 12, 2021 (edited) 8 hours ago, dcairns560 said: Thanks for the replies gentlemen. Got the transaxle just about ready to pull out. Hope to have it apart tomorrow and figure out the issue If you have any questions please ask and let us know what you find. Good Luck pulling the hubs they can be a bear. D200 Hub pulling... Edited July 12, 2021 by pfrederi 2 1 Share this post Link to post Share on other sites
daveoman1966 3,751 #13 Posted July 12, 2021 While you have this D torn down, I'd urge you to examine the internals of the HYD MOTOR for damage or wear. If you find wear or internal damage, it is likely that the Hyd Pump likewise suffers....since the Hyd Motor and Hyd Pump have common fluid (ATF), and that the soft brass internals are nearly identical. Lastly, since the D is 45+, it is bound to need attention tot he Hyd Drive overall. I have two .pdf files that I've developed to help you restore the Sundstrand power system. SUNDSTRAND Piston-Piston PUMP & MOTOR Refurb.pdf D SERIES ALL LIST (3).pdf 1 Share this post Link to post Share on other sites
dcairns560 6 #14 Posted July 12, 2021 Got the transaxle out and the case split apart about 3/4". I can see a broken bolt laying down in the bottom. Need to get a puller from work so I can get the hubs off and take it the rest of the way apart. Is the case gasket available for purchase anymore? 1 Share this post Link to post Share on other sites
daveoman1966 3,751 #15 Posted July 12, 2021 If you can get the cases halves far enough apart, reach in with a couple long box-end wrenches and remove the 3 or 4 remaining bolts holding the differential together. With those bolts out, you completely separate the gearbox cases, then take the L/R axles to a hyd press to get the hubs off. 2 2 Share this post Link to post Share on other sites
pfrederi 17,739 #16 Posted July 12, 2021 Don't try a regular 3 jaw puller on those hubs unless they move easily. The hub flange is very thin compared to the length of the hub. Either pull from behind or as daveoman suggests take the differential apart to get the axle out then use a press. Lowell at wheel horse parts and more has the case gasket you need. Absolutely do not use RTV little bits of that stuff can get into acceleration valves https://wheelhorsepartsandmore.com/ Share this post Link to post Share on other sites
dcairns560 6 #17 Posted July 12, 2021 2 hours ago, daveoman1966 said: If you can get the cases halves far enough apart, reach in with a couple long box-end wrenches and remove the 3 or 4 remaining bolts holding the differential together. With those bolts out, you completely separate the gearbox cases, then take the L/R axles to a hyd press to get the hubs off. Not having any luck getting the hubs off. I don’t see any bolts inside that I could remove. Do you happen to have an exploded view of the transaxle so I know what I’m looking for? Share this post Link to post Share on other sites
WHX?? 48,815 #18 Posted July 12, 2021 Download that manual Paul has posted above. It has a IPL. 1 Share this post Link to post Share on other sites
pfrederi 17,739 #19 Posted July 12, 2021 It isn't easy to get to them. but there they are. I pulled my hubs (you only have to get one). Not easy but nothing working on a D series is... 1 Share this post Link to post Share on other sites
dcairns560 6 #20 Posted July 13, 2021 Thanks for the additional pictures, I did download the manuals you shared earlier I just must have missed the section on the axle. I got one of the hubs off... and destroyed it in the process . The rest of the bolts were not very tight either, and I can see where there was a crack in the bottom of the case that someone had "fixed" with jb weld . Luckily I have an identical parts tractor so this evening I removed the transaxle from it. Are these loose bolts a common occurence on these models? Just wondering if I should pull the other axle apart to check them or just stick it in there and run it. Im assuming that the washer in my picture goes where all the needle bearings go? 1 Share this post Link to post Share on other sites
daveoman1966 3,751 #21 Posted July 13, 2021 This is the schematic from the Toro MPV. Gearbox of the D-160. The washer in your above pic is the THRUST WASHER (4-29B) and is on the short side of the 46-tooth gear (4-29A). 1 Share this post Link to post Share on other sites
daveoman1966 3,751 #22 Posted July 13, 2021 For schematics, go to: https://lookup3.toro.com/partdex/index.cfm?xCaller=Toro Enter D-160 as model, then clik SEARCH. A model listing will appear...then clik thru the ASSEMBLY DRAWINGS for schematics of the tractor. 1 Share this post Link to post Share on other sites
dcairns560 6 #23 Posted July 13, 2021 10 minutes ago, daveoman1966 said: For schematics, go to: https://lookup3.toro.com/partdex/index.cfm?xCaller=Toro Enter D-160 as model, then clik SEARCH. A model listing will appear...then clik thru the ASSEMBLY DRAWINGS for schematics of the tractor. Thats an awesome resource, thanks! Share this post Link to post Share on other sites
pfrederi 17,739 #24 Posted July 13, 2021 I would open up the new transaxle and replace all the differential bolts with Grade 9. 1 Share this post Link to post Share on other sites
pfrederi 17,739 #25 Posted July 14, 2021 You will need to replace the O rings and special washer between the manifold and hydro motor. PM me your address I will send you a set... Share this post Link to post Share on other sites
