How to measure driveshaft length with slip yoke Chevy?

To measure the driveshaft length on a Chevy that uses a slip yoke, determine the distance between the centerlines of the front and rear universal joints. This center-to-center measurement is the key dimension when ordering a replacement shaft, and you can obtain it with the shaft in place or by removing it for a precise,Hands-on measurement.

Understanding the slip-yoke setup

Many older Chevy rear-wheel-drive trucks and full-size cars used a two-piece driveshaft with a slip yoke at the transmission tail where the front half slides in and out. The length you need to order is based on the center-to-center distance between the two U-joints (the front one at the slip yoke and the rear one at the opposite end). Modern or later-model vehicles may use a single-piece shaft or a different slip mechanism, but the core idea remains: center-to-center length is the critical spec, not just the housing length of the slip yoke.

Chevy configurations to know

For Chevrolet trucks and many older cars, the common setup is a front slip yoke connected to the transmission tailshaft and a rear universal joint that bolts to the differential. When replacing a driveshaft, vendors typically request the center-to-center length (between the two U-joint centers) and the U-joint size, plus confirmation of slip-yoke type and spline count if applicable.

Tools and safety

Before you start, gather the right tools and take basic safety precautions. A clean workspace, a helper, and clear lighting will help you avoid mistakes and injuries.

• Tape measure (preferably steel for accuracy)


• Marker or chalk for marking centerlines


• Straightedge or ruler


• Flashlight or work light


• Chocks and jack stands or ramps for level height


• Socket/wrench set to remove the driveshaft if you choose to take it off

Using the right tools and a safe setup reduces errors and prevents injury while you take the measurement.

In-vehicle measurement: measure with the shaft installed

These steps let you measure without removing the driveshaft, which is convenient if you’re trying to confirm a length for a replacement while the shaft remains in place.

1. Park on a level surface, engage the parking brake, and chock the wheels. Make sure the vehicle is cool and secure before you work.


2. If possible, jack up the rear of the vehicle just enough to relieve load on the driveshaft, then support the driveshaft with a strap or friendly helper to prevent sagging.


3. Identify the front U-joint centerline (the joint near the transmission slip yoke) and the rear U-joint centerline (the joint near the differential).


4. With the driveshaft oriented along its natural line, measure from the center of the front U-joint to the center of the rear U-joint along the driveshaft’s axis. Use the marker to keep your measurement straight and aligned with the shaft.


5. If the slip yoke is extended or retracted, note the measurement at the shaft’s current position. The slip yoke will slide during operation, so use the length at a typical ride height and neutral position for a replacement reference.


6. Record the length in inches (to a tenth or hundredth of an inch if possible). Repeat once to confirm accuracy.


7. Compare your measurement to the shaft you’re replacing or ordering. If your vehicle has multiple driveshaft pieces, you may need to measure each segment’s center-to-center length separately and verify assembly fit.

Accurate center-to-center measurement with the shaft installed reflects the real operating length the replacement must achieve. If access or clearance is poor, removing the shaft for measurement can yield a clearer result.

With the shaft in place, your measured length should guide you toward the correct replacement. If you cannot access the centers easily, removing the driveshaft makes the measurement cleaner and reduces the chance of error.

Alternative method: measure with the driveshaft removed

If you prefer a direct measurement of the two U-joint centers, remove the driveshaft and lay it on a padded surface. This method eliminates in-vehicle interference and allows a clean center-to-center measurement.

1. Secure the vehicle and support the transmission with a mount or stand if needed, then disconnect the driveshaft at the rear U-joint or slip yoke end.


2. Mark the centerlines of both U-joints on the driveshaft, using the cross centers as reference points.


3. Place the shaft on a flat surface. Measure straight along the shaft from the center of the front U-joint to the center of the rear U-joint.


4. Record the measurement in inches with as much precision as possible. Double-check your marks and re-measure to confirm accuracy.

Measuring on a flat surface often yields a more repeatable result, especially if the vehicle’s chassis or exhaust interferes with a clean in-vehicle measurement.

Interpreting the measurement and ordering a shaft

The critical dimension to relay to suppliers is the center-to-center length between the two U-joints. In many cases, this is referred to as the “overall length” of the assembled driveshaft. When you order, also confirm:

• The U-joint size at each end (e.g., 1310, 1330, etc.).


• Slip-yoke type and spline count on the transmission tailshaft (to ensure compatibility with the front half).


• Whether the shaft is a full-length, single-piece unit or a two-piece with a slip joint, if applicable to your model.

Having clear photos or measurements helps a supplier match the correct shaft and avoids fitment issues. If you’re unsure, bring the old shaft as a reference or consult a pro shop for a precise measurement.

Summary

For a Chevy with a slip yoke, the essential measurement is the center-to-center distance between the front and rear U-joints. You can obtain this by measuring the shaft in place or by removing the shaft for a clean, straight measurement. Always confirm U-joint sizes and slip-yoke specifications with your supplier, and consider having a professional verify the measurement if you’re unsure. With the correct length and proper fit, you’ll restore proper drivetrain alignment and vibration-free operation.

How far should a slip yoke stick out?

A slip yoke should stick out approximately ¾ to 1 inch at ride height, ensuring there is enough spline engagement for stability while also allowing for suspension travel without bottoming out. For some applications, particularly those with significant suspension travel, a longer engagement of 2 inches or more is necessary. 
This video explains how to measure for a custom driveshaft and set up the slip yoke: 1m2CarProsYouTube · Apr 22, 2023
Key guidelines for slip yoke engagement

• Minimum engagement: Always maintain at least ¾ to 1 inch of spline contact to prevent vibrations and ensure stability. 
• Maximum engagement: Avoid pushing the yoke too far in. It should not bottom out on the transmission tailshaft, as this can cause damage, especially when the suspension is compressed. 
• Adjust for travel:
  • Street cars: ¾ to 1 inch is typically sufficient for street cars, especially if they are low to the ground. 
  • Off-road or high-travel vehicles: Vehicles with a lot of suspension travel require more engagement, sometimes 2 inches or more, to prevent the slip yoke from coming apart or bottoming out during suspension compression. 
• How to measure: Push the yoke all the way in, then pull it back out by the desired amount (¾ to 1 inch) to check your clearance and engagement. 
• Check for leaks: A leak from the seal could indicate the yoke is being pushed in too far, so monitor for this. 

Where do you measure driver shaft length?

I pull the tape measure out. And I put it at a similar angle pull the club to the tape measure. And see what the nearest round number is here it's normally pretty close. This one is 38.

How to measure a 2 piece drive shaft?

I prefer measurements from center of u-joint to center of hanger bearing mount holes and then from center of hanger bearing mount holes to center of u joint or flange plate on the rear end.

How do you measure a slip yoke drive shaft?

To measure driveshaft length with a slip yoke, you need to measure from the center of the rear universal joint (U-joint) on the transmission to the center of the U-joint on the differential, after the suspension has been loaded and the slip yoke is in its operating position. To do this, first push the slip yoke into the transmission to the point where it is fully compressed, then pull it out ¾ to 1 inch to create your operating position. Next, use a measuring tape to go from the center of the transmission's U-joint cap to the center of the differential's U-joint cap to get the final measurement.
 
This video shows how to measure a driveshaft with a slip yoke: 33sMonster TransmissionYouTube · May 24, 2019
Before you start

• Load the suspension: Ensure the vehicle's weight is on the suspension. You can do this by having the wheels on the ground or placing safety stands under the axle. 
• Compress and set the yoke: Push the slip yoke on the transmission end all the way into the transmission. Then, pull it out ¾ to 1 inch to establish the correct operating position. 

Step-by-step measurement

1. Measure from transmission U-joint to differential U-joint:
   • Place one end of a rigid tape measure on the center of the U-joint cap on the transmission's slip yoke.
   • Extend the tape measure to the center of the U-joint cap on the rear differential.
   • Record this length accurately. 

You can watch this video to see an example of measuring from the U-joint to the differential: 1mSpeedway MotorsYouTube · Jan 16, 2023

1. Verify U-joint and yoke sizes: 
   • Measure the width of the U-joints and the diameter of the U-joint caps to confirm the sizes. This is necessary for ordering a new driveshaft. 
2. Record all measurements:
   • Write down the final driveshaft length and all other measurements, such as the U-joint and yoke sizes, to provide to your driveshaft supplier.