Staked in Ujoint replacement how-to

Discussion in 'Modifications And Maintenance' started by Chux, Aug 28, 2018.

  1. Chux
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    Chux Well-Known Member

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    Alright, new ujoints in my '04 Outback, and it rides like butter. So nice.

    Got these joints from AutoZone:
    [​IMG]
    20180105_175646
    by Numbchux, on Flickr

    Here's how:


    1. The joint before I started, you can see some of the 8 little "stakes" being deformations in the outer yoke holding the caps in.
    [​IMG]
    20180827_192114
    by Numbchux, on Flickr

    I've seen 2 ways to do staked in joints (generally, not specifically Subaru), one is to grind the stakes out, and the other is to just use a press to push through them. In my experimenting on other shafts, it takes an enormous amount of force (easily the most I've ever done on my little 12 ton HF press), so I opted to grind first.

    High speed metal cutting bit on the dremel does a pretty good work down in the corners.
    [​IMG]
    20180827_192401
    by Numbchux, on Flickr

    While I had it out, I used the dremel to make a few light marks on the yoke and the shaft itself to ensure the orientation when it came time to reassemble.
    [​IMG]
    20180827_192552
    by Numbchux, on Flickr

    2. Then over to the press, make sure to support the other end of the shaft pretty well.
    [​IMG]
    20180827_192748
    by Numbchux, on Flickr

    3. Once it's pressed off to one side, the stakes become really clear (some of these are ground down, some are un-touched).
    [​IMG]
    20180827_192926
    by Numbchux, on Flickr

    4. Flip it over and press it back all the way through to flatten those stakes. Then lay it with the opposite yokes supported (a vice works best for this), and pound on the yoke so those cups can be pushed out beyond the ears. Don't pound on the thin part at the top of the ears, and don't pound on the shaft tubing itself.
    [​IMG]
    20180827_193255
    by Numbchux, on Flickr

    5. Flip over and repeat the other way until those cups are pushed as far out of the yoke as possible. It should get to the point where the cross of the ujoint can be removed from the yoke (if those cups are damaged, you might need to sneak a punch passed the cross to push the cup out further, just make sure not to damage the yoke).
    [​IMG]
    20180827_193408
    by Numbchux, on Flickr

    6. Then pound the cups out the rest of the way:
    [​IMG]
    20180827_193515
    by Numbchux, on Flickr

    Rotate the shaft 90*, and repeat steps 1-6 to remove the other 2 caps, and remove the joint completely.

    7. Now switch to a softer dremel bit (wire wheel or sanding drum work well) to clean up the inside of the yoke, you want to smooth everything out without taking off really any material. You'll also want to run a flat file across the inner surface of those ears, as the new joints will be held in place by snaprings against this surface.
    [​IMG]
    20180827_195537
    by Numbchux, on Flickr

    8. Now to start preparing the new joint. The four cups need to be removed from the center cross, inside those cups are needle bearings which have to stay in place, and the only thing holding them there is grease. They *should* be pregreased with assembly lube for this purpose, but I don't trust it, so I hold the caps in place by hand and gently pump some fresh grease through them:
    [​IMG]
    20180827_194557
    by Numbchux, on Flickr

    9. Then pull the caps off. You'll notice I removed the grease zerk from the one cap to protect it from damage, this is optional, but IMHO a good idea.
    [​IMG]
    20180827_194833
    by Numbchux, on Flickr

    10. Put the cross in the middle of the yoke, and one of the caps in from the outside. You want to hold the cross inside the cap as tight as possible as you press on it to help keep those needle bearings in place.
    [​IMG]
    20180827_194903
    by Numbchux, on Flickr

    11. Then press it in well past it's final resting place. This simplifies putting on that snapring, and aligning the opposing cup.
    [​IMG]
    20180827_201328
    by Numbchux, on Flickr

    12. Put the snapring on the one cup, then put the opposite cup from the other side, and again slide the cross into the new cup as you press it in. This is a bit tricky, as you have to get it pressed in far enough to get the second snapring on, but you don't want to put too much pressure on the bearings to damage them (although, the cross should bottom out in the cups before the needle bearings bear the brunt of the weight)

    Back to step 10 to finish the other half of the joint, taking care to reassemble in the same orientation that you started with.

    Install the grease zerk (if you removed it), and grease.
    [​IMG]
    20180827_203215
    by Numbchux, on Flickr

    Now flip the shaft and do it all again at the other end.

    Install in the car, and enjoy!
     
  2. JasonoJordan
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    JasonoJordan Well-Known Member

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    Nice work! Did you run into any balance issues at all? I would not expect you to but well subaru.
     
  3. Chux
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    Chux Well-Known Member

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    I was a bit worried about that, as the new joint has to be perfectly centered in order to maintain balance, and since the new joint is centered in a different method than the old one it seems completely possible that it would be different.

    That said, I put about 5 miles on it, all at 70+ mph, and it was buttery smooth. Planning to put about 700 miles on it this weekend, I'll have a pretty good idea by then.
     
    JasonoJordan and tangledupinblu like this.