This page will help you determine the information needed to order our Custom Engineered Driveshafts. You will need:
Here’s a quick video made by our good friend and customer Cleetus McFarland on how to measure for a driveshaft (with a nice shoutout to PST at the end).
A note about the video: In the video above, they measure to the BACK of the pinion yoke and take off 1/4”. We ask that you measure to the FRONT face of the pinion yoke and do NOT take 1/4” off. See Diagram N at the bottom of this page and look for the “X” Measurement – that is what you will need to provide us. If you have any questions, please let us know.
Continue reading below for everything that you will need to measure for your driveshaft. If you have any questions, you can always feel free to send us a message or give us a call at 727-442-1711.
The first thing that you’ll need to do is to identify your transmission.
Chrysler – Dodge
727 – 30 Spline 1 11/16″ Seal Diameter
904 – 26 Spline 1 9/16″ Seal Diameter
Ford
C6-T56 – 31 Spline 1 11/16″ Seal Diameter
AOD & C4 & T5 – 28 Spline 1 1/2″ Seal Diameter
4 R 7OW – 28 Spline 1.598″ Seal Diameter
General Motors
T-350 700R4-4LLOE – 27 Spline 1 1/2″ Seal Diameter
T-400-4L80E – 32 Spline 1 7/8″ Seal Diameter
For T-400, 4L80, 4L85 and 6L80 Transmissions: We will need to know if your 32 spline Output Shaft is drilled and tapped (has a threaded hole in the end).
Note: Transmission slip yokes are manufactured with various U-Joint Series. It is important to match Horsepower and Torque requirements to U-Joint Series. For aftermarket transmission applications usually a spline count and seal diameter will identify slip yoke required.
As always, if you need help, you can contact us.
The next thing that you’ll need is to identify is your rear U-Joint. To do that, you’ll need to measure the “Cup Diameter” of the joint, as well as the length of the joint. We strongly recommend that you make your measurement using a set of digital calipers, since deviations as small as 1/16” can call for a different joint.
There are hundreds of Universal Joints sizes (U-Joints) or “Series” to accommodate many different applications of power and desired longevity for your automotive, 4×4 truck or auto racing requirements. However, these 4 series of joints cover most needs.
1310 Spicer Series:
1330 Spicer Series:
3R Saginaw Series:
1350 Spicer Series:
The following diagrams may be helpful to you as well.
If Pinion Yoke has Placement tabs that retain the U-Joint, measure inside tabs. See Diagram D.
If Pinion Yoke does not have Placement Tabs that retain U-Joint, measure from flat of yoke inside to inside. See Diagram E.
If 4 bolt Flange is used on pinion, measure Pilot Diameter and center to center diagonally bolt hole to bolt hole. See Diagram L.
The Driveshaft Measurement is the “holy grail” of the measurements that we need. While a U-Joint or slip yoke can be swapped out, in most cases the length of the driveshaft once built can not be altered (it can only be shortened, and even then it is not always possible). It is very important for us to have the correct driveshaft length measurement before starting production on your shaft. Please make sure that you measure twice.
If PST is supplying you with a transmission slip yoke, then we will need Dimension “X” in the Diagram above. This is the measurement from the seal of the transmission to the face of the pinion yoke/flange. See Diagram N above. This measurement must be made with the car at ride height, and if you have a “rubber boot” on the end of your transmission make sure you measure all the way into the transmission seal.
If PST is supplying you with a transmission slip yoke and pinion yoke, then we will need Dimension “W” in the Diagram above. This is the measurement from the seal of the transmission to the pinion seal.
If you are ordering a 2-piece driveshaft, then we will need Dimension Y and Dimension Z in the Diagram above.
Critical Speed is the RPM at which the driveshaft is computer projected to bend or whip. See below for our Critical Speed Chart, which shows the maximum RPM broken down by length of shaft and by material of the shaft. You will see that there is increasing strength from Steel/Chromoly to Aluminum, and from Aluminum to Carbon Fiber at every driveshaft length. Please make sure that you are building a driveshaft that will withstand the maximum RPM of your vehicle.
View our PST Critical Speed Chart >>
Don’t worry. If you have any questions, you can contact us at 727-442-1711 or send us a message.