John Deere 450c dozer transmission issues

[SChunter1991]

I am the proud owner of a john deere 450CC Dozer sn #: 195007T with unknown hours and unsure of machine history. I have changed the transmission fluid(used tractor supply john deere equivalent), cleaned the screen and replaced the filter I noticed fluid inside the bell housing when making the adjustment after fluid change. I believe I may have over filled the transmission as the level appeared high on the dipstick. I drained fluid out until it was at the proper level. I used a boroscope to inspect inside the housing and there appeared to be 2-3” of fluid in the bottom of the housing. I then dropped the skid plate and cleaned out the drain port at the bottom of the bell housing. After getting the fluid level right I haven’t noticed anymore accumulation of fluid in the bell housing.

I went through the HLR adjustment and found the pressure to be low. I removed the pressure control valve cap and found there were already shims stacked in side the cap. I was only able to add one shim and still get the threads to catch. After adding the shim the pressure was in range per the spec. I then went back through the HLR adjustment procedure. Initially, the machine would push and shift great. Both tracks would spin when pushing against an immovable object. However after running the machine for approximately 20 minutes it became weak and unable to push much of anything. The shift also became sluggish. I have used the machine several times and each time it performs the same. Strong initially, then progressively weaker. What else do I need to look at?

[Jim B]

Welcome to the Boards.

You may have some seals starting to fail. Cold oil can hide some leakage. As the oil and components warm leakage will increase. The other thing is a pump that is worn generally drops off as it warms. If you leave the gauge in place does the oil pressure change as it warms up?