Understanding Drive Shaft Measurements For Lifted Suspensions

Any time you add a lift to the suspension of your truck, it's important to ensure that the entire drivetrain maintains the geometric angles required to keep the truck handling properly. If you're installing the lift on your own, chances are good that you're familiar with most of those components, including the drive shaft. Here's a look at what you need to know about how the lift affects your drive shaft and what you can do about it.

What Happens To The Drive Shaft When You LIft Your Truck?

Your truck's stock suspension is based on precise geometric angles so that every component connects in the right place and responds appropriately without getting bound up. When you add a lift to the suspension, it changes that geometry. If all of the components, drive shaft included, aren't addressed, you may find that the geometric angle is altered and the truck doesn't handle correctly. In some cases, it can cause the drive shaft to bind, which might destroy the shaft.

How Do You Fix The Problem?

The only way that you can fix an ill-fitting drive shaft after you lift the suspension is to install a new, longer drive shaft. You can order a new shaft when you order the suspension lift if you want to, but if you forget or aren't sure what size you'll need, you can measure for it and order a custom drive shaft after you've got the lift installed and you know how the geometry is altered.

How Do You Measure The Drive Shaft?

Raise the truck with a jack and position some jack stands on each side of the axle shaft, just inside the wheel. Lower the jack to secure the truck on the jack stands, that way it is stable while you work.

Start by measuring the distance from the transfer case U-joint to the rear axle differential. The drive shaft will connect on both ends. For an accurate measurement, you need to start with the flat edge of the transfer case U-joint and measure straight to the flat portion of the differential, maintaining the straight line between the two. If you're not familiar with some of the specific terms, the differential is the large ball-like component in the center of the axle. You may have heard it referred to as the axle pumpkin, too.

You'll also have to measure the distance between the caps on the U-joint, too. Start at the outer edge of the cap on one side and measure to the opposite edge of the cap on the other side. You'll need that distance to ensure that you get the right width. Measure both U-joints, because you'll need to know the specifics on both the transfer case end as well as the axle end.

Armed with those dimensions, you can work with a custom drive shaft manufacturer to craft one that will fit properly and maintain your suspension's integrity and control. Contact a local company, like Jons Shafts and Stuff or a similar location, for more tips and info.