axle swap ujoint information

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GreaseDog

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i compiled this information for posting on another site, and thought that it may be useful here as well.
Universal joints:
Swapping a 14 bolt in place of a 10 bolt can get a little tricky to some because of the possible need for a conversion U joint. All 14 bolts that i have seen, both SF and FF, use a Spicer 1350 U joint. With this said, GM doesn't commonly use a Spicer 1350 joint on 1/2 ton trucks, most commonly they use a Saginaw S44 joint. I have however seen Spicer 1310 joints, and the occasional Spicer 1330.

Obtaining a positive ID on the joint isn't hard at all, just pull the joint, and measure it. If by chance you have stock U joints, you'll have to take a torch, and heat the caps up until all of the nylon melts out of the driveshaft and oozes out of the holes. Rather than using a retainer clip like the replacement joints do, GM uses an injected nylon retainer. Now that you've got the U joint out, you can measure it and see what it actually is. Here are the specs of the 4 above joints:

Saginaw S44: Cap diameter- 1.125", Lockup - Internal (clips inside the yoke) 2.556"
Spicer 1310: Cap diameter - 1.063", Lockup - External (clips outside the yoke) 3.219"
Spicer 1330: Cap diameter - 1.063", lockup - External 3.622"
Spicer 1350: Cap diameter - 1.188", Lockup - External 3.622"

Now that you have determined the stock U joint, you can find which conversion joint you need:

Straight Size Joints:
S44 Neapco PN: 2-3011
1310 Neapco PN: 1-0153
1330 Neapco PN: 2-4800
1350 Neapco PN: 2-0053

Conversion Joints:
S44 to 1350 is Neapco PN 2-1153
1310 to 1350 is Neapco PN 3-3140
1330 to 1350 is Neapco PN 2-3050

If by chance you have any other combination, which would be an extremely rare case, you can look up the joints by size here: http://www.aawheel.com/SiteResources...oUniversal.pdf Dimensional listings start on page 260.
 

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thanks good info there

I vote for some glue on this one
 

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Bump. I thought this became a sticky?
 

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conversion

i recently swapped in an sm465 and np208 transfeer case in my 74 k10 then i ran into the problem of the rear u joint as the driveshaft is mid 80s and the rear end is a '74 10 bolt. has anybody ran into the problem befor and if so what did you do? Is there a conversion u joint?
 

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i recently swapped in an sm465 and np208 transfeer case in my 74 k10 then i ran into the problem of the rear u joint as the driveshaft is mid 80s and the rear end is a '74 10 bolt. has anybody ran into the problem befor and if so what did you do? Is there a conversion u joint?

Need to know what joint your new shaft uses, your combo could have had two different sizes depending on what truck it came from. The chart posted at the top will tell you, if you are able to measure your u-joints.
 

HotRodPC

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If the rear end is a 10 bolt, it's not original either. 74's had the 12 bolt rear axles.
 

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