Replacing U-Joints: Do You Prefer a Hammer or a Press?

A Hammer or a Press?


  • Total voters
    91
I have always just used a 16oz ball peen hammer for extraction and install. I use some kind of wood to support the yokes. I usually don't have to pound very hard. I clean up the yoke with a light sand paper to get all of the dirt out and the burs off that might have accumulated. Then I spray a light wd40 or penetrating oil in the yoke. Then lightly tap them back in. I then put the clips back in then tap the corners of the yokes to make sure nothing bound or tight.
 
  • Like
Reactions: KCsTJ
With the right tool and a press, you wont bend the ears. I have had ujoints so corroded that they sound like a .338 going off when they let loose. Oh and what do the drive shaft shops use? I have seen Tom Wood's press...
 
  • Like
Reactions: Brianj5600
You can screw up either way, but a big ball peen hammer and TAP gently with an anvil, huge vise, concrete curb for backing is the cheapest, easiest way.

Using any kind of a press needs real concentration. Use finese, be square, true. You should be able to install with a stubby ratchet, if you need a snipe, you are doing it wrong.

Best, unlimited budget, a full on floor mounted hydrallic press with the correct attachments.

Number One.... Keep everything square.
 
  • Like
Reactions: KCsTJ
What do we do when an old u-joint just won't come out? Tworley and I had to admit defeat on one tonight while rebuilding a pair of axle shafts. We finished one with a hammer, but getting it apart was the biggest fight I've ever experienced doing this. The install was as easy as it should be. The passenger side shaft was worse. We only got the caps off of the inner shaft, but could not get the outer disassembled. Even a vise would not get the caps to move.
 
Last edited:
What do we do when an old u-joint just won't come out? Tworley and I had to admit defeat on one tonight while rebuilding a pair of axle shafts. We finished one with a hammer, but getting it apart was the biggest fight I've ever experienced doing this. The install was as easy as it should be. The passenger side shaft was worse. We only got the caps off of the inner shaft, but could not get the outer disassembled. Even a vise would not get the caps to move.

Were they factory? See my post earlier about the plastic ring they inject. Once you burn it out, the caps move MUCH easier.
 
Were they factory? See my post earlier about the plastic ring they inject. Once you burn it out, the caps move MUCH easier.

Sealed Spicer joints in alloy shafts. We took a propane torch to it and the plastic was essentially burned out. We tried everything on it. Luckily I had a spare shaft to throw in but my next step in a big press to get the old caps out
 
Were they factory? See my post earlier about the plastic ring they inject. Once you burn it out, the caps move MUCH easier.
Factory front axle shafts don't use the injected plastic. At least my 2003's didn't. I've only seen that in the front drive shaft.
 
Mapp will work better than propane. Any joint you have that doesn't have a visible snap ring is probably held in with plastic. Not sure why the factories are doing that, but its pretty common.
Fast and easy and when you have several thousands to do, every little bit helps. A lot more common that folks recognize though. My first car was a 67 Chevy Caprice and the driveshaft caps were retained the same way.
 
I've used all three, but keep going back to a 1.5 lb shop hammer with the appropriate sized socket. I also have 12" long piece of railroad track that I use for an anvil.
 
Open the jaws wide enough to set the yoke on top and let the cap fall through. A large socket as a receiving cup works in a similar way. I don't think I've actually clamped down on anything. At least not recently. The vise is just a hard surface to work on. The back end of the shaft is supported with blocking.
Just replaced the 3 ujoints on the front shaft last weekend. That is exactly how I did it. It also gave me an extra set of hands when reassembling the CV end, but I clamped close to the joint to avoid damaging the tube itself. It mostly just held everything still so I could tap in the new caps.
 
Hammering the caps in is still easier than pressing them in. Even after last night's experience. You're guaranteed to get them in straight.
 
One school of thought says they should almost go in by hand .

I think the Teflon injected factory process is amazing by the way. Pretty smart use of plastic.

Does anyone approach the ones behind the front wheels differently than the rest?
 
How in the world does anyone get the retainer back on the u joints?!?!?! I’m about to throw my rear drive shaft into the front yard. Tomorrow is trash day
 
The u joint retainer. The metal one you have to use needle nose pliers to pry out. They go on each end of the u joint itself. And yea it’s exposed plenty. The issue is, it just won’t go in or fit?? I’m using needle nose to compress it but they get in the way. Any suggestions?
 
I usually stick them in the recess above the cap and then tap them into the groove.