What is differential preload?

What is differential preload?

Preload is the static load across the differential, this a base level of resistance between the two wheels. It is determined by measuring the torque taken to turn one output shaft whilst the other is still stationary.

How is pinion preload measured?

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.

Why preload is required?

Why Preload? The purpose of preload in a bearing system is to eliminate clearance that is designed into standard ball bearings. Almost all radial ball bearings are made with a clearance or space between their components to allow for free movement.

What is a preload gauge used for?

Preload is used to pre-compensate for wear in the bearings (prevents the bearings from getting loose as they wear), and is defined as the amount of rotational drag induced by the load on the bearings. It is measured as the amount of torque required to turn the diff slowly.

What does pinion preload mean?

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.

How do you measure preload?

It requires cutting out a piece of cardiac muscle to look at the sarcomeres under a microscope. It is currently not possible to directly measure preload in the beating heart of a living animal. Preload is estimated from end-diastolic ventricular pressure and is measured in millimeters of mercury (mmHg).

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

If the preload is set too tight the pinion bearings will wipe out, fail, lock up and cause a catastrophe ring and pinion gears. If the preload is set too loose the rear end will whine, the pinion gear will attempt to walk up the ring gear causing abnormal gear wear and eventual fail.

How do you adjust the preload on a differential assembly?

Move differential assembly to one side of the housing with lever and set gauge to zero. Lever assembly over to the other side and note gauge reading (A). This figure indicates the play in the bearings and the thickness of shims needed to take up play. Add .004 – .006 in to total to give preload.

How do you check for Backlash on a Salisbury axle assembly?

When the assembly is complete, check for backlash (.004 in minimum). Change shims from one side to the other of differential bearings if necessary. WATCHPOINT: In Salisbury axles, the carrier is integral with the axle housing. A removable cover at the rear, gives access to the final drive components.

Which LSD differential for the plus 87ha Salisbury?

WATCHPOINT:QUAIFE, the famous UK differential specialist, does a replacement LSD differential for the Plus 87HA Salisbury axles that incorporates the latest Quaife technology. Effectively, it turns a 7HA into the best axle Morgan classics ever had, namely a 12HA, fit just before the BTR era began.

Can you swap axles on a Morgan Salisburys?

WATCHPOINT: Morgan Salisburys were made specifically for Morgans ONLY. These parts were no longer being made (for many, many years). For this era, the best solution was an axle swap, the easiest being to the later BTRs, the axles currently used by Morgan.