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datzenmike

U joint replacement

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A squeak, increasing with speed, like Mini Mouse at orgasm is a sure sign that one or more U joints has gone dry on your truck. (or car) Soon after, the needle bearings will break and or seize briefly, sometimes producing a 'ping' sound, not unlike a light hammer tap on the hollow drive shaft, when under load. Sometimes the U joint won't do either but, will go directly to loose, causing the drive shaft to move off center and wobble. That's a lot of weight spinning around under there, and it only takes a little slack, to cause a lot of vibration. As the vibration increases, so does the wear, and the needle bearings will fall out. It's only a matter of time until the trunnion (the cross shaped thing) wears a hole in the bearing cap and ruins the yoke or worse flies apart. You do not want 30 lbs of violently spinning metal coming loose just a foot away from your valuable <em>parts</em>.

Keep your U joints greased and inspected for wear (looseness) every 3-4 months. Some are permanently sealed (don't last any longer, maybe cheaper) get replacement ones that you can grease.

To inspect, I leave in neutral, raise one rear wheel and grab opposite sides of the yoke and try to twist in opposite directions. Next i push and pull at right angles to drive shaft rotation. Don't be shy, really lean on it! There should not be ANY looseness in the U joint itself. Rotate the drive shaft and inspect for any damage such as dents or worse a wobble. A dent doesn't mean it needs replacing but it does indicate that it was hit pretty hard and may have bent the shaft. Don't mistake the rear end gear lash as looseness. The shaft should turn smoothly with no binding, squeaking or roughness. Look for oily discoloration around the bearing cap seals, a sure sign that grease is leaking out.

OK we have located a possible candidate for replacement so mark the yoke so you can re-assemble it in the same relation. First remove the 'C' clips or split washers. A screw driver works but they sometimes fly out, so be careful. A new joint should have replacement ones, USE them! A little WD-40 is good now.

Copy%20of%2000270011.jpg

Well, you can use a vice with two different size sockets... or, give the yoke a few smart raps with a hammer and the inertia of the trunnion and the other yoke will drive the bearing cap out. Flip over and do the other side. Wear ear plugs and don't hit the shaft pipe, only the solid yoke. A 4-5 lb hammer works best! When the second cap is half way out there may be enough room for the trunnion to fall out. That's OK finish driving the cap out with a punch, or twist out with pliers.

Copy%20of%2000270012.jpg

Two caps are off and you can see the row of needle bearings and the grease seal. Now do the other half.

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A vice works best for assembly. Be sure that the needle bearings don't fall out of place and get crushed, check constantly until well started. One side will always finish going in before the other.

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As soon as one side is far enough in, install the NEW 'C' clip to hold it. Yes, I'm reusing the old clip because I wasn't replacing the joint, only the yoke for one with a longer spline (bottom photo) You may have to tap the other cap in against it to make enough room for the other clip. Here the left side is in and being clipped so it won't pop out while pressing the other side in.

Copy%20of%2000270015.jpg

Well, surprise! This little piggy has gone dry for whatever reason and water has rusted it and worn marks into the trunnion. Squealed like a pig. Sometimes the bearings fall out in in chunks. A U joint with a grease nipple will flush out water and any dirt and keep fresh grease in there.

Copy%20of%2000270013.jpg

For $5 get the rear tranny seal and replace it any time the shaft is out.

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Remember: "Don't Bogart that joint" get it replaced before it smokes you!

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Nice write up Mike.

Your tech notes on drive shaft angle and vibration is pretty too.

Goes hand in hand with this I think.

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Thanks Mike for the good article and especially the great pics. This will sure help on my next u-joint job. I sure won't be guilty of letting one bite me in the rear-end again. I know the true meaning now of the old saying (an ounce of prevention is better than a pound of cure)! Dan

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A squeak, increasing with speed, like Mini Mouse at orgasm is a sure sign that one or more U joints has gone dry on your truck. (or car)

what i wanna know is how do you know what noises minnie mouse makes at orgasum :lol::lol::lol:

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hey man can you put the pics up again? looks like they're "moved or deleted"

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I've P/Md Thomas, who was kind enough to replace the auto transmission pictures in the Drivetrain 'sticky' for me. This was totally my fault. Thank you again Thomas.

 

Hopefully the U-joint pictures will be up soon.

 

mike

 

edit: Wow, up faster than I could wright this!!!!!!!

 

BTW I wasn't Mini's first...... but I sure spoiled her for Mickey.

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I've P/Md Thomas, who was kind enough to replace the auto transmission pictures in the Drivetrain 'sticky' for me. This was totally my fault. Thank you again Thomas.

 

Hopefully the U-joint pictures will be up soon.

 

mike

 

edit: Wow, up faster than I could wright this!!!!!!!

 

BTW I wasn't Mini's first...... but I sure spoiled her for Mickey.

 

 

THANKS MAN! you rock

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mann my 620 viberates like hell and it sounds like something is scratching near the transmission but not sure if it is the u joint help please:)

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Probably the rubber isolation ring around the hanger bearing has rotted off. Take a look under there. The drive shaft is made of two pieces with a U joint at each end and one in the middle. Just forward of the middle U joint will be a wrap around support on the drive shaft. Between the support and the drive shaft is a rubber doughnut inside a thin metal ring that looks like this on the rear side :

 

http://i138.photobucket.com/albums/q251/datzenmike/620driveshaft003Large.jpg[/img]"]620driveshaft003Large.jpg

 

... and like this on the front side:

 

http://i138.photobucket.com/albums/q251/datzenmike/620driveshaft002Large.jpg[/img]"]620driveshaft002Large.jpg

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Sweet writeup!! I'll be using this info for sure!! I've done them, but the method of hammer on the yoke instead of the cup...nice!!

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be sure to get the greasable u joints to prevent yourself from doing this again!!!!!!!!!!!!!!!!!!!!!!!!!!!!! grease them every oil change or when you check your oil or tire pressure!!!

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Thanks Datzenmike and crew for a very informative and helpful writeup with photos. Is the rubber donut still available at the auto parts stores? The problem I have is not any squeaks or consistent drivetrain vibration ('77 620 KC), rather a clunking noise when I'm lugging up a steep hill. Under light load driving conditions everything is fine. I have crawled underneath, but couldn't detect any slack, but I didn't do as thorough an inspection as Datsunmike describes.

 

Dan

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If you get the greasable kind, there's a specific way to put them in. The load has to rotate and basically, compress toward the fitting.

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I have to replace a couple of U-joints on the 510

Which reminds me....need another vice, the last one snapped...

Cheap China crap...lol

 

ds7.jpg

 

ds8.jpg

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I'm not sure if you'll see this since it's an older thread, but I'll post it separately if no one see's it.

 

So I'm replacing the U-joints on my 1978 B210 GX 5 speed.  They were well past the squeak stage and had moved into the vibration stage.

 

I'm having difficulty getting the right replacement U-joint.  Oreilly's is usually my go-to for most stuff.  The only 1978 Datsun they have in the book was a 110.  I believe the part number for the U-joint was 393 or maybe 392.

Anyway, we ordered it and it is just a little too big.

The ends of the U-joint are the right size for the yokes, but they don't come in far enough to get the retaining rings on because the center of the U-joint is beefier than the original.

 

My question is 2-part:

 

Does any one know the correct U-joint to get for a 1978 B210 GX 5-speed front and rear on the driveshaft?

or....

Since the bigger U-Joint fits, but can't be secured by the retaining clips, what if I just spot well a little on the outside of the yoke to keep it from coming out?

I'll have to take really good care of it since I'll never be able to replace it again.  (at least not very easily)

 

Thanks for any info!

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My B-210 had the pressed in and staked in place, non replaceable U joints. Is this the case here? There will be no clips or the groove to hold them. If you look into the ends, to the bearing cap, you can see that something square has been pressed in to displace metal and hold the U joint in place.

 

A shop can drive them out and cut new grooves for the clips. This was certainly one of Nissan's bone head moves to make a high wear part totally non replaceable by the owner.

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My B-210 had the pressed in and staked in place, non replaceable U joints. Is this the case here? There will be no clips or the groove to hold them. If you look into the ends, to the bearing cap, you can see that something square has been pressed in to displace metal and hold the U joint in place.

 

A shop can drive them out and cut new grooves for the clips. This was certainly one of Nissan's bone head moves to make a high wear part totally non replaceable by the owner.

 

Like many new cars... ^^

 

Some of these have this plastic shit that holds them in.. then you just need to torch them out. Then you can replace. Not sure if Nissan used this design.

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My old '79 Cutlass was this way. Rather than heat I just 'shocked' them out in the usual way with a hammer. The grooves (at least) are there and new clips with the replacement U joints fit right in. I don't know of Nissan being this smart.

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My U-joints are replaceable.  They look similar in design to the photos at the beginning of this thread.  They have the very same type of semi-circular clip holding them in, but the U-joint itself looks to be smaller.

I took some pictures.

 

Here is the replacement I received partially installed.  I am holding the old one next to it to show the difference in size.  The old one and new one have the same size of outer roller diameter, but the over-all width of the U-joint is smaller on the old one.

fc5929e2-6022-4752-8470-c011b2ff6df6_zps

 

 

Here is the Newer one in the Yoke.  It sort of fits, but when it's in the middle of the yoke, I won't be able to get the clips on.

d6fceeb4-ce80-4447-9478-3abd9603db79_zps

 

 

And so I'm wondering if I can just weld the ends of the roller caps a little bit to keep the U-joint in place?

Here is a picture.  I would weld just a little bit on the outside of the roller and the yoke next to where my thumb is:

e061a191-0cfa-4a79-8c1f-8159a865a154_zps

 

 

Welding scares me for two reasons, I might not get the U-joint centered as well as the clips would, which might make it vibrate.  Also, I am worried the weld would damage the roller.  I am not worried about replacing it in the future.  I don't plan to put THAT many more miles on the car.  (knock on wood).

 

Obviously, the best solution would be to get the correct U-joint, but I have not been able to find a part number anywhere for it.

 

Any recommendations?  There are some other parts shops I can try, but I reckon they will have the same incorrect on listed.

 

Thanks guys.

Mike

 

 

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No welding. You will never get it exactly in place and the drive shaft will wobble and vibrate. Find the correct ones for it and preferably with a grease fitting to make them last longer.

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