The differential lock on my 710B has never worked. After spending the entire morning digging this out of the bowels of the machine, I'm ready to attempt a repair on this differential lock valve. The shaft on the left is frozen. I have the manual and I will follow it in my repair attempt, but I would like any insights from people who have disassembled one of these before - any issues, or pitfalls that the manual glosses over. View attachment 361719
Deere 710B Backhoe Differential Lock Frozen
Started by SLK00115 replies
SLK001New Member#1 mg2361Senior Member#2 SLK001 said: any issues, or pitfalls that the manual glosses over. Click to expand... Nope.
stephenrobinson98741New Member#3 SLK001 said: The differential lock on my 710B has never worked. After spending the entire morning digging this out of the bowels of the machine, I'm ready to attempt a repair on this differential lock valve. The shaft on the left is frozen. I have the manual and I will follow it in my repair attempt, but I would like any insights from people who have disassembled one of these before - any issues, or pitfalls that the manual glosses over. View attachment 361719 Click to expand... If the shaft is frozen, the most likely culprit is corrosion or old contaminated oil gumming things up inside the valve. Take plenty of pictures as you disassemble it and keep the parts in order—some of those springs and spool components can look very similar when it comes time to reassemble. I'd be careful applying force to the shaft. Soak it with penetrating oil and work it gradually rather than trying to drive it out. Also inspect the bore closely for scoring or rust once you get it apart. One thing the manuals don't always emphasize is checking the linkage and actuator side too. Sometimes the valve itself isn't the only problem, especially if the diff lock hasn't worked in years. Good luck—getting that valve out is often harder than rebuilding it! Let us know what you find once it's apart.
SLK001New Member#4 I managed to get the shaft out, but not without destroying it. First, the end broke off trying to twist it loose. Since I now had to make another shaft, there was no need to keep it pristine, so I grabbed it with a pair of Vice Grips. It STILL wouldn't rotate, so I took a high speed die grinder and ground a pair of flats on the shaft. Now, using a 12" Crescent wrench AND a 24" cheater, I was finally able to get some rotation. Mind you, this was all the while keeping it flooded with PB Blaster. Other than the destroyed shaft, the rest of the parts were in excellent condition. It was missing the inner spring that goes inside the larger spring on the pedal side. I've ordered a replacement and pick it up on Wednesday. The spool and the bore are in great shape, too. And I have a bone to pick with both the manual people and the parts diagram people. There are two large spacers that go behind the valve that do not show up anywhere. The only way I found out about them was because one of them fell to the ground. I had to remove the floor plate once again to find the other one sitting on top of some hoses. Next week, I'll fabricate the new shaft and clean everything and finish the rebuild. I should be able to reinstall the valve in early July. It will be nice to finally be able to use the differential lock, especially on hills and in the mud.
Tyler d4cSenior Member#5 #19 is the spacers
SLK001New Member#6 This is the image I've been using. You mean tat there are two places this is shown?
Tyler d4cSenior Member#7 I cant see them on yours the bolts that hold it on are 4 and 5 and the spacers are 19. Where you getting your diagram?
Tyler d4cSenior Member#8 SLK001New Member#9 I've been looking in: 710B and 710C Backhoe Loaders - PC1845 3 TRANSMISSION 3 HYDRAULIC SYSTEM 0360 MECHANICAL FRONT WHEEL DRIVE CONTROL VALVE (710B) https://partscatalog.deere.com/jdrc/sidebyside/equipment/18862/referrer/navigation/pgId/1987755 Even the two valves are different. Yours doesn't have the small inner spring that mine is missing (according to the manual).
Tyler d4cSenior Member#10 Somewhere i seen tge valve updated they probably forgot to add the spacers and bolts to the updayed one or something like that. I ve seen that happen with deere already on other things
smifwalSenior Member#11 i like this stuff, I will compare it kroil but cheaper. Not saying it would have freed up your shaft but it is a better than PB blaster. Also tranny fluid and acetone 50/50 if there is no rubber involved
SLK001New Member#12 I fabricated a replacement shaft. See the old and the new together, below. Here is the valve repaired and reassemblred. I got everything reinstalled and hooked up, only to find out that one of the hoses had a hole in it. And it was the most difficult hose to install (the small hose on the top). It has to be installed BEFORE the valve is mounted, so everything had to come out (you can imagine that I was not happy). But everything finally got installed and the floor plate, seat and floor mat buttoned up. The difference is like night and day with the diff lock now working. Going up a steep hill goes from "I don't know if I can make it..." to "Wow, this thing has power to spare..." Also, being able to operate the machine all day without it vapor locking is a definite bonus!
SLK001New Member#13 Since the machine is operating quite well now, I thought that I would redo the seat, since it was very uncomfortable to sit in. This is the seat I started with: The seat after a new skin: The end result: I didn't take photos of the original seat back, but it was even rattier than the seat bottom. All-in-all, the improvement is fantastic!
HarleyHappySuper User#14 Nice work!
edgephotoJunior Member#15 Nice job!
Welder DaveExpert#16 Great job on the new shaft! Nice when you can make and do repairs yourself and save a lot of money. I've saved thousands by knowing how to weld.