At JE Reel Driveline, we are widely recognized for building rugged custom Jeep driveshafts. However, our 40+ years of racing passion and technical expertise extends across all automotive fields—including muscle cars, hot rods, drag racers, and everyday all-terrain vehicles.
Getting an exact measurement is absolutely critical. Two identical vehicle models can require completely distinct driveshaft lengths due to factory configurations or aftermarket modifications, such as adding a suspension lift kit.
Fortunately, finding your precise measurement is simple, stress-free, and only requires a standard measuring tape.
Critical Step Before You Start: Check Your Ride Height
Before crawling under your vehicle, ensure it is resting at its normal ride height on its suspension (either parked on its wheels or sitting on a drive-on hoist). Do not take measurements while the vehicle is lifted on a bumper jack or frame-anchored jack stands. An unloaded suspension stretches the distance and will alter your final length calculation, causing severe fitment issues later.
How to Measure Your Driveshaft in 4 Simple Steps
Step 1: Identify Your Setup & Measurement Endpoints
Your starting and ending points depend entirely on how your driveshaft connects to the vehicle’s transmission, transfer case, or differential. Look closely at your current driveline setup; you will be measuring between one of three common attachment types:
- The center of a universal joint (U-joint)
- The flat face of a transmission or transfer case flange
- The tip of the output tail shaft/spline extending from the transmission
Step 2: Choose Your Specific Vehicle Application
Select your vehicle style below for the exact instructions required for an accurate measurement:
🔹 Option A: How to Measure a Jeep or 4×4 Driveshaft
If your 4WD driveline features a traditional yoke setup on both the axle and the transfer case, you will perform what is known as a “center-to-center” measurement.
- Locate the front U-joint (at the transfer case) and the rear U-joint (at the axle yoke).
- Hook your tape measure directly over the center of the front U-joint.
- Stretch your tape to the exact center of the rear U-joint. This center-to-center distance gives you your overall running length.
- Note: If your system uses a companion flange instead of a yoke, simply measure from the flat face of that flange to the center of the opposing U-joint (or to the face of the second flange if you have two).
Option B: How to Measure a Car or Muscle Car Driveshaft
When measuring a vehicle with a slip yoke that slides directly into the transmission tail shaft, your process changes slightly depending on the parts you currently have on hand:
- If you HAVE the transmission slip yoke: Slide the slip yoke completely onto the transmission output shaft splines until it bottoms out. Pull it back out roughly ¾ inch to 1 inch allow for normal suspension travel. Measure directly from the center of that transmission yoke’s U-joint to the center of the rear differential’s U-joint (or flange face).
- If you DO NOT have the transmission slip yoke: Measure directly from the flat tip of the transmission’s output tail shaft housing to the center of the rear U-joint or the flat face of your differential flange.
Step 3: Double-Check Your Numbers
Measure twice to save time and frustration. Write down your exact specifications. If you are upgrading to a high-performance part like a heavy-duty 1350 driveshaft, even a fraction of an inch matters to achieve a perfectly balanced, vibration-free power transfer.
Step 4: Submit Your Specs to a Driveline Specialist
Once you have written down your dimensions, you are ready to build. Take these metrics to a trusted shop to have your custom steel, aluminum, or carbon fiber driveline precision-engineered.
Need Expert Help?
Speak to a Driveline Pro
Don’t risk guessing on your custom measurements. With over 140 years of combined technical expertise, the team at JE Reel will ensure your custom build fits perfectly the very first time.
Call Us: 909-629-9002
Email Us: contact@jereel.com