Driveshaft u-joints

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Jul 30, 2021 | 08:12 PM

Prionus

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Mountain Pass

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Driveshaft u-joints

1982 F350 CC 351W. I noticed that my driveshaft u-joints don’t have a zerk fitting to grease them. These are original to the truck. Do they simply have to be replaced? Or can they be greased somehow? How can I tell if they are bad?

Jul 30, 2021 | 09:28 PM

FuzzFace2

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From: Angier, NC

You dont grease them, till they go bad.

As for how to tell if bad:
Some times when taking off from a start you get a chirping noise bad joint.
When taking off or under a heavy load you can get a vibration.
When looking them over if it has rust leaking out of the caps its bad.
With the truck out of gear and brake set / wheels chocked try and turn the drive shaft be hand checking the joints for play.
Dave ----

Jul 31, 2021 | 12:33 AM

BigBlue2

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Quote:

Originally Posted by Prionus

The original u joints are sealed. They cannot be greased. When they wear out you can replace them with sealed bearing u joints like the originals or greaseable u joints.

Sealed u joints last about 100,000 miles and are maintenance free. Greaseables require a few squirts of grease every 3,000 miles. Properly maintained Greaseables may last for half a million miles.

So pick your poison....

Jul 31, 2021 | 06:47 AM

FuzzFace2

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From: Angier, NC

Another note greaseables are a little weaker joint than non-greaseables.
You ask why is that?
Its because the greaseables are hollow to allow grease out to each cup where the non-greaseables are not hollow.

Its not a big deal to 99.9% but if you have a high HP / TQ motor you put under a heavy load most of the time or do any kind of racing, the weak ones can let go right when you dont want them to.
Dave ----

Jul 31, 2021 | 08:59 AM

Prionus

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Mountain Pass

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Thank you both. I’ll just leave sleeping dogs lie for now. They don’t make noise and are very tight. T18 isn’t hitting it hard either. Good info on the solid versus hollow Dave G. I didn’t know that.

Jul 31, 2021 | 03:52 PM

BigBlue2

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Quote:

Originally Posted by Prionus

With our trucks you don't need to worry about breaking a greaseable u joint because they are hollow. Yeah with a race engine you can probably break any kind of u joint. Heck I've seen drive lines twisted into candy canes.

The sealed ones are also subject to failure, especially when they get some miles on them. I change my own oil, so while waiting for the oil to drain I squirm around on my creeper and grease up the u joints and the steering joints. The original steering joints were sealed too. They only last 100,000 too.

I replaced them all with greaseables and added another 300,000 miles on them and counting.

Aug 1, 2021 | 02:10 PM

BigBlue2

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I saw a video on YouTube about Spicer's sealed u joints. They say their high quality sealed u joints will last the life of the vehicle. They didn't give a mileage estimate with that. Bit if they warrant lifetime as in as long as you own the vehicle it's probably worth looking at a high quality sealed u joint. I'm old school and at the time I replaced my sealed units that was the best option IMHO. I have been happy with that choice because at that time there were no lifetime sealed u joints. My driveline shop recommended the greasable for long life.

Times change, so if you're looking for maintenance free then sealed deserves a look.