How to spot a bad U-Joint

[ISX]

I compiled this video to better explain how to check U joints. Think I pretty much explained everything in the video. If you take them apart, use a dead blow hammer, NOT a regular hammer, you can bend the yoke and then the U joint bearings will not line up. Sometimes it becomes necessary to use a regular hammer but be extra careful where you hit! Make sure you put threadlocker on the 8mm bearing caps, mine have come loose on me and I have heard reports of the same thing happening to others. I found a very detailed website if you want to learn more about all the driveshaft components. http://www.pirate4x4.com/tech/billavista/PR-shaft/

http-~~-//www.youtube.com/watch?v=959Jhv3JWcA

I will make a video taking them apart this afternoon, just in case someone wants to know how.

[Mopar1973Man]

Not bad... But you need more sun on your legs... Seriously... That will be handy for the noobs here on the site. The only thing I add to the inspect is with a whole shaft segment out I would try to twist at each joint back and forth feeling for movement (slop) ans during you pivot movement pay attention to the feeling of movement. Is it loose and gritty or is it firm and smooth...

[ISX]

Yes the play will tell you something is wrong. It shouldn't hardly have any at all. When mine went out, the grease had all washed out. There was nothing but rust powder, no bearings whatsoever. The only reason I caught it was because you would hear a lot of popping, which was the bigger particles of bearing fragments being smashed. Like I said, 2wd will not notice anything, it barely uses any bearing movement because it is so straight, so the only way to check is like I did in the video. Other than the popping mine had, I couldn't tell a difference, but you see in the video where I pryed the U joint out of the yoke and it hit the ground..when the u joint was bad, I had to do a pullup on the driveshaft with all my weight to get it to come down. I thought it was still in the yoke, nope, bearings were just that bad, but I never noticed it while driving, because of the straight shot.

Don't give me that crap! There is a big tan line where my shoes are.

--- Update to the previous post...

Alright here is how to tear it apart. I do have one of those double Ujoint things here like this one that I can tear apart if you guys want to see how those tear down..

http-~~-//www.youtube.com/watch?v=huePbcN65JU

[Mopar1973Man]

Actually the best way to actually do all u-joint is with a press. Most of us don't have one but a press is the best way to do it... Double cardian joints are fun to do... I would do a video on that if you could I'm sure someone here will need to change them soon.

[ISX]

The best way is with the biggest hammer you can safely swing! Presses take too long to mess with, but are definitely the best way. A hammer puts a ton of force on it for a second, when a press only puts the amount of force needed on it, plus you can center it and get things to make the force balanced and yadda yadda, but yeah nobody has one, and a deadblow does a good enough job, just takes some time. You just always have to be keeping an eye on what you are hitting, the ears of the yoke won't bend that easily but you still must be very aware of them. Also have to make sure the needles are staying in place, if one falls out and you start beating it into place, you will probably mess the bearings up and have to find another. On a side note, when you buy new u joints, you get everything but the driveshaft, meaning everything I took off of that driveshaft in the video (bearing caps, the joint the caps go on) all are replaced. You don't reuse one or the other, so as long as you take precautionary steps on keeping the driveshaft and yoke in good shape, the joint itself can be taken out by some pretty *constructive* means depending on how easy the caps are to remove.

[guesswho512]

good videos. do you (or anyone else) have information such as part#'s or weight capacity? what brand were your greasables? what about that center supported bearing? i assume that you take the grease boot off and separate the 2 shafts?

Launch shudder is a vibration that occurs at first acceleration from a stop. Shudder vibration usually peaks at the engines highest torque output. Shudder is a symptom associated with vehicles using a two-piece propellershaft. To decrease shudder, lower the center bearing in 1/8 inch increments.Use shim stock or fabricated plates. Plate stock must be used to maintain compression of the rubber insulator around the bearing. Do not use washers. Replace the original bolts with the appropriate increased length bolts.

are there any shims there stock? i dropped the shaft for better access to the fuel tank when i installed my airdog. maybe they didn't go back in? i am trying to find and fix a vibration that is at low rpm. i can't tell if its rear tires or driveshaft problem thanks for the help

[ISX]

Not sure on any numbers or weight stuff. I think the new ones I got were neapco or spicer. Can't remember which one they were able to find a cross reference for.

Your right on the center support bearing removal.

There are no shims there stock, on mine anyways, just 4 bolts. The only shudder I get is the clutch grabbing too much when I am taking off.

Does it vibrate when you are moving and push the clutch in? Have you tried putting the front tires on back and vise versa? Any difference as you are hitting the brakes?

--- Update to the previous post...

The double cardan joint I have has plastic retainer thingers. You have to heat them up and melt it out then they will come out. It is still a good joint so I don't want to tear it apart. I used another one yesterday, took it apart to see if it would even come apart, all the caps fell off and needle bearings fell out so I can't really use that again lol.

I did find a very good tutorial on how to do it though. http://www.mallcrawlin.com/forum/showthread.php?t=7478