What is difference between 1310 and 1350 joints?

The main difference between 1310 series and 1350 series is size and strength. The 1310 series joint is what you would expect to find stock in most Jeep or small trucks. A 1350 series joint/shaft is what you might find in many full size trucks. While it's not 100% accurate, you could say that a 1310 is a "half ton" joint and a 1350 is a "one ton joint".

What are U-joints?

U-joints are flexible connectors in the drivetrain that allow the driveshaft to rotate at different angles while transmitting power.
Upgrading the u-joints also means that all of the yokes and most other parts of the shaft are upgraded to bigger, stronger, parts.

1350 U-Joint: Pros and Cons

Pros: Significantly stronger than 1310 U-joints (about 37.5% more torque handling). Ideal for heavy-duty rigs.
Cons: More expensive, potentially slightly less flexible than 1310s

When to consider upgrading to 1350 U-joints:

Front or Rear: Because the rear shaft is the primary shaft and does most of the work most of the time, it usually needs to be a little stronger than the front. Because of this, we have slightly different recommendations for the front and rear shafts.
Large tires: 35-inch or bigger create more strain.
High horsepower: More power stresses the drivetrain.
Upgraded drivetrain: If your axles and/or transfer case are bigger and stronger than what came stock in your vehicle your drive shaft should be upgraded accordingly.
Aggressive driving: "Send it" mentality increases the risk of breakage.
Weight: Heavy rigs (especially overland builds), or towing puts more stress on components.
Gear ratios: Numerically low ring and pinion gear ratios (3.29, 3.56, 4.10, etc) mean your drive shaft is spinning slower and with more load than if you have numerically higher gear ratios (4.88, 5.13, etc), which increase the speed and decrease the effort required from the drive shaft.
Rigorous off-roading: Steep angles and harsh terrain need stronger parts.
Future upgrades: Build with growth in mind.

Other factors to consider:

Shaft Angles: Short wheelbase = steeper angles, where the flexibility of a 1310 could be better.
Drivetrain component strength: Match the driveshaft to the rest of the system. Sometimes this means moving up in size, sometimes this means sticking with the stock size.
Cost: 1350 setups cost more, and might require new yokes.

The bottom line:

If you're pushing your rig with the factors listed, a 1350 U-joint upgrade offers greater durability and peace of mind. However, weigh the cost difference and specific needs for your vehicle.

Get a more detailed explanation by clicking here .