- Measure cap diameter and span with calipers to identify a u-joint.
- 1330 = 1310 caps on a 1350-width cross.
- 1350 is the go-to upgrade for big tires, lockers and high horsepower.
- Combination u-joints let you mix series at one joint.
U-joint series dimensions
| Series | Cap diameter | Span (across caps) | Typical use |
|---|---|---|---|
| 1310 | 1.062″ | 3.219″ | Most stock cars, Jeeps, half-ton trucks |
| 1330 | 1.062″ | 3.625″ | Factory performance cars, some trucks |
| 1350 | 1.188″ | 3.625″ | 3/4 and 1-ton trucks, high-HP and big-tire builds |
| 1410 | 1.188″ | 4.188″ | Heavy-duty trucks, extreme off-road |
| 1480 | 1.375″ | 4.188″ | Extreme torque and heavy use |
| 1550 | 1.375″ | 4.969″ | Extreme torque and heavy use |
Ford also used "big cap" 1310 and 1330 joints with 1.125″ caps on the same spans. Full chart and printable measuring worksheets: u-joint identification chart.
Series Drivetrain Industries builds
| Line | Available series |
|---|---|
| Custom & performance | 1310, 1330, GM 3R, 7260, 7290, 1350, 1410, 1480 and 1550 |
| Heavy duty | 1610, 1710, 1760, 1810, SPL170 and SPL250 |
| Industrial | 687.50 up to 390.60, including 15C and J1200 series |
How much stronger is 1350?
1350 is the meaningful jump. Its bigger caps and needle bearings make it roughly 37.5% stronger in torque capacity than a 1310. Commonly cited Spicer ratings put the 1310 at about 130 lb-ft continuous / 800 lb-ft short-duration, the 1330 at about 150 / 890, and the 1350 at about 210 / 1,240. Real-world strength also depends on joint quality, whether it's greaseable, and the yokes it's in.
The 1330 "myth"
The 1330 uses 1310-size caps on a wider cross. Some builders argue the longer lever arm makes it no stronger than a 1310 in practice. Published ratings show a modest increase in continuous torque and a bigger increase in short-duration torque. Bottom line: 1330 is a small step up from 1310, and 1350 is the real upgrade.
How to identify your u-joint series
- Measure the cap diameter with calipers: about 1.062″ or about 1.188″.
- Measure the span, the width across the outside of two opposite caps (not counting clips).
- Match both numbers to the table. Can't measure? Text a photo with a tape measure next to the joint to (572) 568-1838 and we'll identify it.
Note: some imports (Toyota, Nissan and others) use metric u-joints that don't match Spicer series. Measure before you order.
When should you upgrade?
- You're running roughly 35-inch or larger tires
- You've added lockers, gearing or several hundred horsepower
- You tow heavy, launch hard, or run a trans brake
- You keep breaking 1310 joints or yokes
Mixing series: combination u-joints
Combination (conversion) u-joints have different-size caps on each axis, like 1310 on one side and 1350 on the other. They let you upgrade the driveshaft while keeping a stock pinion yoke, or match an upgraded yoke to an existing shaft. They're useful, but the joint is only as strong as its smaller side.
Greaseable or solid?
For strength, solid (non-greaseable) joints win, because there's no grease channel drilled through the cross. For off-road rigs that see water and mud, a greaseable joint that's actually greased can last longer. More in bad u-joint symptoms.
Frequently asked questions
Is 1330 stronger than 1310?
Slightly. The 1330 uses the same size caps as a 1310 on a wider cross, which gives a modest strength increase. The 1350, with larger caps, is the substantial upgrade.
How do I know if I have a 1310 or 1350 u-joint?
Measure the cap diameter with calipers: about 1.062 inch is 1310 or 1330, about 1.188 inch is 1350 or 1410. Then measure the span across the caps to tell them apart.
When should I upgrade to 1350?
Upgrade to 1350 for tires around 35 inches or larger, lockers, heavy towing, high horsepower, or if you've been breaking 1310 joints.
Can I put a 1350 driveshaft on a 1310 pinion yoke?
Yes, with a combination u-joint, or by changing the pinion yoke to 1350. The combination joint is only as strong as its 1310 side.
Can you build 1350 driveshafts in Oklahoma?
Yes. Drivetrain Industries in Edmond builds custom driveshafts in 1310, 1330, GM 3R, 7260, 7290, 1350, 1410, 1480 and 1550 series for custom and performance, 1610, 1710, 1760, 1810, SPL170 and SPL250 series for heavy duty, and industrial series 687.50 up to 390.60, including 15C and J1200 series. Call (572) 568-1838.