Inside Snap Ring Universal Joints and Yokes
Inside snap ring components come in a few sizes for automotive applications. They are found in older GM, Chevrolet, Dodge products and some imports. The yokes and universal joints pictured are for reference only and your parts may look a bit different than these specific parts, but if yours is an inside snap ring u-joint simply match your measurements to the chart for series identification.
Shown is a Spicer Life Series universal joint with “C” snap rings and the improved bearing cap seals. This joint has a forged rather than cast body for extra strength and life – it is an OE style 100,000 mile universal joint.
A is the measurement between snap ring grooves and B is the bearing cap diameter. Cap diameters are best measured with dial calipers but a good tape (with a good eye) that is marked in 16th’s of an inch will work fine.
The yoke shown is a PTI 3R Series u-bolt style. These yokes come in dozens of configurations – different spline sizes and counts, different seal diameters, etc. Also the universal joint may be held in the yoke with u-bolts or straps. This type of yoke may be found on the output shaft of a transfer case or on the pinion shaft of a rear axle. The measurements are the same as those on the joint: A is the snap ring “lockup” dimension and B is the bearing cap diameter. Notice that this yoke has no tabs at the bottom of the joint cap bores, as do outside snap ring yokes. It is the inner machined surface of the yoke ears than hold the snap rings in place.
TROUBLESHOOTING NOTE: The universal joint caps with snap rings in place should fit snugly between the ears of the yoke. If the joint can be moved from side to side across the yoke the yoke is worn should be replaced. The snap rings hold the joint on the centerline of the yoke. A worn yoke moves the joint off the centerline and thereby shifts the attached driveshaft off it’s centerline which can and does cause vibration. A perfect driveshaft will not run true in a worn yoke.
INSTALLATION NOTE: If yours is a u-bolt style yoke we recommend replacing the u-bolts when the joint is changed. U-bolts can stretch and not hold properly over time. Also heed the torque specification when tightening nuts on u-bolts! A u-bolt can be easily overtightened, crushing the u-joint bearing cap out of round. Many u-bolt style yokes have been discontinued and replaced with strap-and-bolt style yokes for this reason.
INSTALLATION NOTE: When fitting an inside snap ring joint into a yoke be sure to turn the caps so the openings of the snap rings face the open side of the yoke. This ensures full snap ring contact with the yoke.
Inside Snap Ring Joint ID Chart
These are the most common inside snap ring universal joints found in domestic automotive and light truck applications – there are others not listed! Please give us a call if you do not find your measurements here.