Autoc120 11 #1 Posted June 28, 2019 I have a 74 c120 automatic and I was mowing the other day and it started to slow down so when i went to grab lever to bring it back to neutral it stayed locked forward and before I know it I'm flying backwards in reverse. I was mowing a hill is it possible that the pump reversed because of slow rpm? I turned the pressure release knob to see if I can free it up but nothing pulled cover and everything looks okay. Any help would be appreciated thanks 2 Share this post Link to post Share on other sites
953 nut 55,777 #2 Posted June 28, 2019 Sounds frightening! When it came to rest would the tractor go in either direction under power? Will the hydraulic lift work with the engine running? If the lift works but it will not move it could be an axle came out of the differential. Share this post Link to post Share on other sites
Autoc120 11 #3 Posted June 28, 2019 The lift works and I have reverse only wide open with the lever stuck forward Share this post Link to post Share on other sites
953 nut 55,777 #4 Posted June 28, 2019 Sounds like a problem with the linkage to the motion control. @daveoman1966 or @pfrederi may chime in with good information. Share this post Link to post Share on other sites
daveoman1966 3,762 #5 Posted June 28, 2019 Me thinks you broke the NYLON CAM # 5996, But, something caused that to happen. It MAY also be that the lock-down tab on the LEFT side is broken, causing the fricton contorl apparatus to fail. OR... or...or... it could be any one (or more) of several things. Also look under the tractor and see if the FRAME PLATE is broken where it bolts to the transmission. This is a repaired frame plate, but you'll know a broken plate when you see it...also very common. 2 3 Share this post Link to post Share on other sites
Autoc120 11 #7 Posted July 4, 2019 Thanks for the help it was a little of both. Frame is broke and it must have flexed enough to pop the shifter out of its guide. Guess I have some fab work to do 1 Share this post Link to post Share on other sites
JCM 9,401 #8 Posted July 4, 2019 @daveoman1966 I have heard you have incredible knowledge on hydro transmissions, I got that little tip from @Stepney when I met up with him recently and he credits that knowledge to you. 1 Share this post Link to post Share on other sites
Autoc120 11 #9 Posted July 5, 2019 Better pic now 1 Share this post Link to post Share on other sites
daveoman1966 3,762 #10 Posted July 5, 2019 3 hours ago, JCM said: @daveoman1966 I have heard you have incredible knowledge on hydro transmissions, I got that little tip from @Stepney when I met up with him recently and he credits that knowledge to you. Yer' makin' my head swell up... lol. I have rebuilt many of the Sundstrands with good success. What are you asking me??? 1 Share this post Link to post Share on other sites
squonk 41,337 #11 Posted July 6, 2019 Yup your frame done broke. I had a similar issue years ago with a hydro. The little allen screw in your pic had backed out. Share this post Link to post Share on other sites
daveoman1966 3,762 #12 Posted July 6, 2019 I am in n/w PA at zip 16433. Me thinks I have a complete frame if you come and get it....freebie, or the scrap yard. Share this post Link to post Share on other sites
