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644E Deere with a clunky rear end pivot.

fast_st · 2019-06-03 12:03

So since it arrived, this 644E would make an awful racket if you filled the bucket right to the top and then drove down some road bumps too fast.. With the help of a bottle jack the other day, picked up the tail and when the weight came off the rear axle, it dropped about 1/2 to 5/8 where the rear is held against that big bracket behind the axle. So the parts listing looks like there's a big fat pin and a bushing perhaps inside the rear housing. Is it possible that I could have all the damage contained to the bushing and pin or can things get outside of that? In its previous life it wasn't too well maintained but now we can get it some mechanical love. It looks like drop the fuel tank shield, Jack and crib and that cross bracket should slip right on out for something like likely weighs north of 500 pounds. Just wondering if there are any trends to watch out for, wrecked cases etc.

Replies16
  1. #1mg23612019-06-03 19:06

    It would be easier to remove the axle than mess with the fuel tank shield. Remove the shield and the fuel tank will still be in the way. Those axles are fairly simple to remove. Just a few hoses, driveshaft and the hardware for the oscillation on the forward and rearward side of the axle. And a really big transmission jack . If you have a big enough spreader bar you lower it with a hoist from above attached at the outer most ends of the axle.

  2. #2Theweldor2019-06-03 19:30

    And...Yes. The wear can get outside of the bushings. But you never know for sure until you get it apart.

  3. #3fast_st2019-06-03 21:42

    Well, dont have a diff lock so just the brake hose. Dont really have a trans Jack, just a pair of 20 ton bottle Jack's and a lot of white oak cribbing, (after a 6x6 pt was turned to splinters, had a white oak sawn into blocks.) Mostly want to take the pressure off, unbolt and raise it up enough to overhaul it. Leave the tires on for spacing off the ground.

  4. #4Nige2019-06-04 06:10

    With 1/2 to 5/8 of vertical movement I think it's likely that the wear will have gone way past the bushing and well into the diff housing and/or the trunnion supports. Usually the fibre bush that goes between the two is only about 1/8 to 3/16 thick. If it's not been greased regularly prepare yourself for grief when it comes apart. Depends on what's available tooling-wise, but for preference we'd lift up the rear of the loader far enough to roll the complete axle out backwards from the machine with the tyres still on it, then pull everything apart once it was clear of the machine. 2nd choice would be to remove the wheels then place a steel plate on the ground under the machine. Lower the complete axle assembly down on to the plate then skid it out sideways. Either way I'd suggest to get the axle assembly right out from under the machine so that you can work on it.

  5. #5fast_st2019-06-04 07:32

    Hmm, I like you less now Nige truth hurts I suppose! I know the forks on the Kubota M70 will just ever so barely lift the front axle as we had the whole unit mostly stripped before, didn't realize at that time the rear bushing was hosed but we overhauled just about everything else. I'm trying to remember where the CG was, but we can crib it near the rear axle on the frame itself. Perhaps order all the parts, get it pulled down and if the housing is tweaked, then give the local welder/line bore guy a call. we can turn a bushing without too much fuss to bring it back into tolerance. Someone did a center bushing where the hole wasn't round, bushing just shattered and made a mess.

  6. #6Nige2019-06-04 09:19

    I'm just trying to prepare you for what I think you're going to find when you tear it apart. Believe me if it is on the floor and away from the machine and you find damage to the hard parts you're going to be thinking "Thank god we pulled this thing right out of the machine" instead of "Now how the ***k do we get this POS out of where it is so we can work on it?" Another thought. Don't entertain any thoughts of putting a sleeve on the pin or inside the trunnion. Welding and boring is the preferred way to go unless you would like it to end up like the photos below. That's the nose end of the diff BTW.

  7. #7kshansen2019-06-04 10:08

    Like Nige says don't go into this job thinking all it needs is a quick "slip in a new bushing and have it out the door by the afternoon job". An extra hours work up front can save several hours of grief down the road. Not to mention the safety considerations of trying to work in a cramped location. Not familiar with the 644E but know all the Cat loaders I ever touched there were two bearings/bushings, one in the rear of the axle and one in the front around the pinion housing. So just because you are seeing slop at one point the chance that is the only one with wear is not going to be the case!

  8. #8Nige2019-06-04 10:40

    Back to cribbing at the Point of Balance. We used to be able to get 994's on the ground fully assembled without using a crane. Basically we cribbed under the front and rear frame for assembly as shown in the photo. When the machine was complete it only needed a small amount of weight in the bucket to get the rear end off the stand so that the stand could be dragged out. Once the rear wheels were on the ground it was a simple matter of jacking the front end up using the bucket to get the front stand out. Is something like that feasible to remove your rear axle using cribbing rather than steel stands..?

  9. #9fast_st2019-06-04 11:42

    I thought filling the grease gun with JB weld was a great idea! .. .

  10. #10fast_st2019-06-04 11:45

    Was this close with only the center section of the rear axle in the machine, would have been primo to find the problem while in this neighborhood, scooped out a lot of metal powder that came from the brake backer as the disk ground against it.

  11. #11fast_st2019-06-04 11:47

    Like at this stage oops, my first undercarriage rebuild on a loader, missed one detail

  12. #12fast_st2019-06-04 12:35

    Nige, if I could borrow your 994, that would make this job pretty easy! Lots of steel plates and white oak cribbing.

  13. #13Nige2019-06-04 12:53

    Have you got something like a forklift that you could reverse into the bucket as ballast..? Also if you think about it, crib under the front frame like my photo above and unbolt the rear axle trunnions from the frame and have some ballast in the bucket - she should pivot around the cribbing as easy as.........then crib the rear frame way up in the air and roll the axle out from under it. Job done.

  14. #14fast_st2019-06-04 18:18

    Sadly no forklift, is a 4.5 to 5 yd bucket, a bit oversized for the machine but it does have the extra rear counterweight.

  15. #15Bls repair2019-06-05 19:01

    You guys must live in bad neighborhoods . I’ve seen cars jacked up and tires taken but never loaders

  16. #16fast_st2019-06-05 21:13

    seriously badass neighborhood!