are simple. Does it have a clip on the outside of the cap that holds
it in? The clip and the cap looks like this on an outside clip. So
on your yoke there’s a grove for this snap ring, or clip.The
cap has a smooth machined surface all the way to the seal.
clips, or inside lockups, have a groove for the snap ring to seat
in machined into the cap itself and the yoke has no groove, just a
flat machined surface for the clip to lay against, keeping it centered.
They look like this:
7260, and 7290 are the 3 major inside clip U joints.
the most part N3R, or S44, is Chevy. 7260 and 7290 are Dodge. Notice
a N3R and 7290 are only .066 difference in their lockup. So instead
of trying to measure these, just look at your truck and ask yourself,
Dodge or Chevy? Simple.
is the smaller of the Dodge U joints. Even with a tape measure, we
can measure the difference between 2.125 or 2 1/8, and 2.622 or 2
5/8. So is it a big Dodge U-joint or a little Dodge U-joint? Measure
CAP & LOCKUP 1310 & 1330 SERIES
hard part always seems to be the cap size. Those fancy sticks that
everyone makes always confuse me, so I started looking for a nice
common object that most people have in their basic tool chest. I discovered
that a 3/4 inch, 1/2 inch drive socket fits into the hole on a yoke
that holds the cap of a 1.063 cap. A 13/16 socket does not. So, if
your 3/4 inch, 1/2 inch drive socket fits into the hole above the
clip of your outside clip driveline and a 13/16 doesn’t, it’s
your tape measure and eyeball the lockup. If it measures a little
less than 3 1/4 it’s 1310. If it measures a little more than
3 1/2 inches it’s 1330.
CAP & LOCKUP 1350 & 1410 SERIES
but what about 1350? For the cap, take a 7/8-inch, 1/2 inch drive
socket and see if it fits. Eyeball the lockup with a tape. 3 1/2 +?
the cap on a 1410, use a 7/8” 1/2” drive socket and a
tape measure on the lockup. The lockup should measure just short of
the caps are the same, only the lockups differ.
CAP & LOCKUP N3R & 7960 SERIES
caps on the N3R and 7960 are about the size of a 13/16 inch 1/2 inch
drive socket. inside clip, of course.
the lockup, as stated earlier, for the most part N3R, or S44, is Chevy.
7260 and 7290 are Dodge. Notice a N3R and 7290 are only .066 difference
in their lockup. So instead of trying to measure these, just look
at your truck and ask yourself, Dodge or Chevy? Simple.
CAP & LOCKUP 1480 SERIES
cap on a 1480 is an easy measure with a tape at 1.375 or 1 3/8"
and looks just plain huge compared to all these others. Use a tape
on the lockup as well.
light duty truck people have just recently started using these 1480's.
have gone to various auto part stores, and it seems that even if it
is an inexpensive foreign set with thin walls on the socket, it will
still get you in the ballpark. So here’s my Dimensions Breakdown:
if this is too Neanderthal for you, then buy a silly caliper and ride
on. This is the easiest I’ve seen. Don’t knock it till
you’ve tried it. Driveline shops speak a different language
than normal people, and it helps when you call them to speak it also.
Once that barrier is overcome, everything gets easier.
far as measuring the driveline length itself, the industry standard
is the center of the cap of the U joint on the end yoke of the differential
(arrow 3), to the center of the cap of the U joint on the transmission
or transfer case (arrow 1). If you have 2 end yokes on your rig, try
to point them both up before measuring (like the diagram). Measure
from the top center of one to top center of the other one.