JD 420 drive shaft u-joints

JDKiotiboys3 · Jul 1, 2012

I need some help on how to get my u-joints out of my 420 drive shaft. Where the driveshaft connects to the transmission , the u joint that's on the transmission is loose ( wobbly ) which in turn vibrates. So , I want to replace that u joint but it seems to be permanently sealed. How do I get that outta there??!!

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Eric Barney · Jul 1, 2012

Are the U-joints available as separate parts? I would not be suprised if you have to replace the entire shaft as an assembly.

zzvyb6 · Jul 1, 2012

Parts list shows cups and c-clips. Pull the c-clips, knock out the bearing cups on the cross (or what's left of them) and pull it apart. New cross(s) come with bearings. Usually lots of needles that can fall out, so be careful !

JD 420 · Jul 2, 2012

I have u joint press it basically is a large C clamp with a hole in the clamp end. You can pick up a cheap one at your local auto parts store. They are made for u joints and ball joints. You can also Use a torch to heat the u joint caps. But before using heat make sure you can get the entire u joint as heat will ruin the old one. Some u joint can be a bear to get out while others seem to slide out smoothly. I have found it is easier to put the drive shaft in a vise weather than trying to it in the tractor. This way the shaft is stable and you won't have to fight it flopping around while your working on it. You can also use a hammer to knock the caps out you just have to becareful not to loose any of the needle bearings.

JDKiotiboys3 · Jul 2, 2012

These caps look like they don't knock out. They look like they would pop outward , not drive inward

JD 420 · Jul 2, 2012

Yes that is correct the whole joint will slide over to push one side of the cap out then push it back the opposite direction to push the other side of the cap out.

JDKiotiboys3 · Jul 2, 2012

ok how do i get the drive shaft of to work on it?

Eric Barney · Jul 2, 2012

JDKiotiboys3 said:
ok how do i get the drive shaft of to work on it?

Since I do not own a 420, and do not have a service manual in front of me, I cannot describe the shaft removal procedure. But, I can tell you: If you have never changed a universal joint before, please find someone who has to help, or do it for you. You should have access to a good work bench with a quality vise mounted on it before attempting this task. You should also be able to handle the pressing of the bearing caps without disturbing the needles, and possibly damaging your new joint assy. A local automotive machine shop will probably change it for you for a minimal charge. Removal of the shaft assembly should be fairly easy, and straightforward.