What is the correct pinion bearing preload?

March 16, 2020 Off By idswater

What is the correct pinion bearing preload?

Depending on the style of the assembly, either a crush collar or shims can be used to adjust pinion depth. Once the pinion depth has been set, pinion preload must be applied while rotating the pinion. For used bearings, set preload at 15 in. -lbs.; with new bearings, set preload with 25 in.

How do you check differential pinion preload?

Use an inch-pound torque wrench to check the preload. If the preload is too loose then remove the shims so that the bearings will be tighter against the races and increase the preload. If the preload is too tight, then remove the pinion gear and add shims so that the bearings will not be as tight against the races.

What can happen if the pinion bearing preload was set incorrectly?

The pinion gear rotates at driveshaft speed and can mimic a driveshaft speed-related vibration. Improper pinion bearing preload can cause what appears to be a pinion seal leak, but the seal is fine, the pinion gear is moving vertically, horizontally, or diagonally as is rotates.

How tight should pinion nut be?

Be careful a quarter turn past optimum is way too tight. You only want 12-20 in. lbs of torque on the free spinning pinion. If you go too tight, the only thing to do is take it apart and crush a new sleeve.

What does pinion preload do?

Pinion bearing preload is the tension placed on the pinion gear’s tapered bearings. This spacer is placed between the bearings. Turning the pinion gear nut crushes the spacer to obtain the specified preload. This preload prevents the sideways thrust that moves the pinion gear to the outside edge of the ring gear.

Why is bearing preload important?

An axial preload ensures constant contact between the ball complement and bearing races reducing or eliminating both modes of play. Properly preloading a bearing can increase its life and eliminate the vibration and noise that results from specified clearance, manufacturing precision, and wear.

What happens if pinion preload is too low?

Too little preload on the pinion causes the seal to leak and can cause gear and/or bearing failure if it’s too much.

How do you fix a loose pinion bearing preload?

Use an inch-pound torque wrench to check the preload. If the preload is too loose then remove shims so that the bearings will be tighter against the races and increase the preload. If the preload is too tight then remove the pinion gear and add shims so that the bearings will not be as tight against the races.

Can I tighten my pinion nut?

What happens if I over tighten my pinion nut?

It takes a lot to tighten pinion enough to crush the sleeve. Too measure preload you definitely don’t want axles in, or the ring gear for that matter. The more you tighten the pinion nut the more the crush sleeve crushes and the more pinion load you will have.

Where is the preload on a pinion bearing?

Pinion Bearing Preload. This spacer is placed between the bearings. Turning the pinion gear nut crushes the spacer to obtain the specified preload. This preload prevents the sideways thrust that moves the pinion gear to the outside edge of the ring gear. It acts as a spring to counter this motion.

What happens if you pre load a differential pinion?

A Pinion with too much pre-load will overheat and destroy the pinion bearings requiring a complete differential teardown and rebuild. My objective was not to reset the Pinion pre-load, but to increase the Pinion pre-load incrementally until Pinion movement was eliminated.

How does a collapsible spacer work on a pinion bearing?

A collapsible spacer is used to obtain the specified amount of pressure or preload. This spacer is placed between the bearings. Turning the pinion gear nut crushes the spacer to obtain the specified preload. This preload prevents the sideways thrust that moves the pinion gear to the outside edge of the ring gear.

What causes a differential pinion to move when torque is applied?

Pinion pre-load is lost gradually over the life of the differential as the bearings and or race wears with use. This wear can cause enough pre-load to be lost that the pinion will actually move when torque is applied or removed to the pinion via the driveshaft under engine acceleration or deceleration.