U joint grease nipple size

does anyone know the grease nipple size of the U joints? Someone broke two off.

1/8"PTF does that sound correct?

1/8-27 is typical on 1610s.

Whats a 1610s?

319cssb said:

Whats a 1610s?

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LMTV/FMTVs use a u joint typical to part number 5-279X or something along those lines. It is a 1610 series joint. If a u joint is a 5-280X like 5 tons M809/939 series trucks have from the transfer case to the front tandem then it is a 1710 series joint. All other joints on a 809/939 series truck at 1610 joints with the 5-279X joints.

1610 series joints usually measure 5.3 to 5.40" across the entire width of it. Cap to cap outer. Typical part numbers 5-279X,M279X,P333,CP16N

1710 series joints measure close to 6" across cap to cap outer typical part numbers 5-280x, M280X, P334, CP17N

1810 series joints measure 7.5" across cap to cap outer.

Added a torque chart for good measure. Also a picture of a 1710 full round yoke vs a 1810 half round yoke for comparison

Another dead give away on telling joint sizes is that a 1610 series joint you would use a 1/2" socket to remove the end cap bolts. 1710 series joints take a 9/16" socket

How ironic I run across this post. I’ve been looking and pricing u joints for my truck wasn’t sure of alt part numbers used.

Now I feel reassured that I was looking at the right parts.


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Man of few words

M1081 LVAD

pontiac62 said:

How ironic I run across this post. I’ve been looking and pricing u joints for my truck wasn’t sure of alt part numbers used.

Now I feel reassured that I was looking at the right parts.


Sent from my iPhone using Tapatalk
Man of few words

M1081 LVAD

Click to expand...

The M279X meritor is cheaper on ebay than anywhere else. However it is a 100,000 mile lube interval joint so for these trucks it would last it's whole life.

Thank you, I'll remember that when I replace the u-joints

The U joint grease fitting size is 1/4" not 1/8-27. I think 1/8 is the size of the fitting by the slip joint