From 1966-70, the Bronco came with a Borg Warner driveshaft, from 71-77 they used a Spicer. Both of these styles used constant velocity joints. If you're not sure, don't go by the year because many of the old ones have been upgraded already. An easy way to tell which one you have is to see if your driveshaft uses external snap rings (Spicer). If you can see the snap rings on the outside of the bearing cap, it's a Spicer.
Another way to tell the difference is to measure the bolt pattern on the transfer case yoke. All of our driveshafts are Spicer style and you will need a transfer case yoke if you are converting from the old Borg Warner.
Wild Horses has driveshafts to fit your specific Bronco. The fact is, that while a stock length driveshaft will still work on Broncos with small amounts of lift, it is not ideal because even with a small lift, the driveshaft is not long enough for a proper fit. We keep driveshafts in stock that will fit from stock to 6" suspensions. We would prefer to use the working measurement to ensure you get the right driveshaft. [This is the measurement from the yoke on the transfer case to the yoke on the rear end center of bearing cap to center of bearing cap with the suspension loaded normally.]
The working measurement is not the measurements of the driveshaft itself, but of the distance between the mounting yokes. The working measurement is measured with the Bronco sitting on level ground and loaded as normal. The rear usually measures 33 1/2-36" and the front 23-25". If your measurement falls between one of our sizes, We generally recommend you order the next larger size (e.g. Your measurement is 34" so you would order a 34 1/2" rather than a 33 1/2").
• A lack of maintenance is the number one cause of driveshaft failure. Driveshafts should be greased regularly, including the constant velocity joint and splines.
• A rebuild kit will not fix a driveshaft that has worn-out splines and slip yoke.