Should I be greasing my U joints?

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cruiser

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Mopar Family: I should probably know this by now, so forgive me for asking. I just noticed that both ends of the drive shaft in my 1974 Duster (225 auto) have Zerk fittings on the universal joints. Looks like each universal joint has two of these grease fittings. I can also see how grease has been flung out from the U joints and has collected on the underside of the car next to the joints. I cannot find anywhere in either my factory shop manual, or my owner's manual, where it says to grease these fittings. So should I be greasing them the way I do all of my front end components? If so, how frequently? How can I tell when they're full of grease, as I don't want to "over grease" them? Thanks.
 
If they have zerks , they need to be lubed periodically. I usually grease every zerk every other oil change.
 
Yes, you should grease the zerts. If overfilled, it will come out through the rubber dust cover on one of the 4 caps. You can tell when it's getting close to that. They don't need to be greased very often but they need grease.
 
Yes, you should grease the zerts. If overfilled, it will come out through the rubber dust cover on one of the 4 caps. You can tell when it's getting close to that. They don't need to be greased very often but they need grease.
Thanks. I'll grease them. It's likely that sometime in the car's past that the U joints were replaced. Did these cars come from the factory with greaseless U joints?
 
The more often you do it the longer it will last. Obviously it will make more of a mess. But keep in mind that a lot of U joints don't even have grease fittings and they have a decent life span.
 
Break out your Factory Service Manual and go to the maintenance / lube section.

Lots of info there
 
The more often you do it the longer it will last. Obviously it will make more of a mess. But keep in mind that a lot of U joints don't even have grease fittings and they have a decent life span.
Yeah, that's the weird part. As I mentioned, the FSM doesn't have any guidance for greasing U joints. That's why I suspect that they came from the factory with non-greasable U joints.
 
You might be surprised after 50 years those greaseable U-Joints could be going bad, flat spotting the cross shafts.

You can take the rear U-joint off the rear end and work it by hand and see if you can feel any roughness. Then carefully pull off one of the bearing caps and check the crossshaft for indents from the roller bearings.

Same with the front yoke. Pull it out of the tranny and run it through the motions to feel for roughness.

Not that bad to just replace them, then you know they are good.
 
Replace them with new non-serviceable ones, aka that don’t have a grease fittings. One of the first things that should be done when buying a car. I learned my lesson in my ram. I old man the owns the drive line shop we use, only uses non-serviceable, as he said every time a broken u joint comes in it is a serviceable aka grease-able one. Here’s my cardon, aka front drive shaft of my truck..

FE07B0ED-34C5-498F-9296-BDBCA7DBE206.jpeg
 
I only use the Non greasable ones in our carss.
I believe they are stronger in my experience with both!
 
There's no such thing as non serviceable or non greaseable U joints. Every single one can be greased with a grease needle up under the rubber boot. I've done hundreds through the years.
 
Moog is what I have used in the past, don't know if they are still available today.
 
Precision, Spicer are what I use.
Typical napa stuff.
Usually 1 maybe 2 greasings are all they get and go 200k+.
I'd use an air gun to dust off grease boogers or just run a rag over it.
Its always a good idea to take a spin up the driveway or block n back then clear/wipe any grease off. Gives it a chance to push out any unnecessary amount.
 
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I would agree with Moog had they not gone global a few years back. Here's what that means exactly. Of course as is obvious, it means they are no longer necessarily made in USA. They might be, but chances are not. Also and even worse, now they are subject to all of the reboxing that parts stores are notorious for. You may order a Moog and it will come in remarked in a "Master Pro" or some other cheap bullshit brand box. That's how they all do it now. I recommend finding a heavy duty truck parts house and getting the bonafide Dana Spicer joint. It will come in a Dana Spicer box and BE a Dana Spicer joint, with the Dana Diamond on the joint, so you know what you have. Yes, it'll cost more, but you'll get a good U joint.
 
Replace them with new non-serviceable ones, aka that don’t have a grease fittings. One of the first things that should be done when buying a car. I learned my lesson in my ram. I old man the owns the drive line shop we use, only uses non-serviceable, as he said every time a broken u joint comes in it is a serviceable aka grease-able one. Here’s my cardon, aka front drive shaft of my truck..

View attachment 1715955992

I prefer greaseable joints. It's when you don't grease them you will have a failure but that's just my preference. I grease them once a year.
 
Put a “grease-able” and “non-greaseable” side by side and look at the design of the caps, bearings and grease disk in the caps. The the cap seals are different and how they handle holding the grease. Also the weak spot in where they drill the hole for the zerk fitting. I’ll never use a “grease-able” one again after loosing the prop shaft in my truck as seen in my other post. But to each their own…

Spicer LV U-Joints Outperform the Competition!
 
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Have the best of both worlds; buy the non-greasable, then drill out one of the caps and install a zerk. I've seen a few like that.
 
I get the spicer non-graceable on everything. They're not hollow down the center so they're stronger...
 
Have the best of both worlds; buy the non-greasable, then drill out one of the caps and install a zerk. I've seen a few like that.
You'd have to install a grease fitting in all four caps, because the non greaseable joints have a solid body with no grease passages. That's why I use a grease needle under the boot of each cap.
 
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