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Differential, Sprite & Midget, Morris Minor, Rebuilt, 3.9:1 With Lsd

Differential, Sprite & Midget, Morris Minor, Rebuilt, 3.9:1 With Lsd

Differential, Sprite & Midget, Morris Minor, Rebuilt, 3.9:1 With Lsd
Selected: Rebuilt Differential, 3.9 Ratio w/LSD
Part No: BTA1222LSD
Specially Priced. Discounts Do Not Apply.
This Item has a $300.00 core charge.
Fits the following:
Sprite & MG Midget
Morris Minor

Rebuilt Sprite, Midget, Morris Minor late type differential with 3.9:1 crown wheel and pinion but with the added major upgrade of a full race Limited Slip Differential with 90/35 ramps. The EVOLUTION limited slip is a modern version of the Salisbury clutch type. It has improved clutch material and a unique design of smooth transitions between loaded and unloaded. Extremely easy and predictable to drive! This design will NOT allow the wheels to spin even if one of them loses contact with the ground. All our limited slips are pre-set for full race applications but can be changed easily for other applications. Modern engineering and design allows variations in static pre-load, percentage torque transfer and accelleration/decelleration action to be made. This facilitates tuning the diff to suit individual requirements and applications - be it road, rally or race! Static settings are easily changed by replacing one diff plate with a thicker one; a selective plate pack is available separately. Static pre-load is checked by holding the unit in a vise and checking slip-point with a torque wrench on one of the crown wheel retaining bolts. Percentage torque bias is increased by interleaving the plate configuration, but is also dependent on ramp angle; shallower ramp angles give higher percentage torque bias. The design of the cross pins and ramps in which they operate allow torque bias changes to be made. The closer to 90 degrees the ramp angle, the less action it has - so a 90 degree ramp effectively unlocks the diff making it behave like a standard diff. Conversely, the shallower the angle, the greater the locking action.

This is a sought after ratio for Sprite and Midget owners who want to reduce engine revs at freeway speeds. This ratio, 3.9:1, was introduced in 1968. This eased the engines revs at speed and provided 16.5 mph per each 1000 rpms in top gear.

This differential includes a new 10 tooth pinion and 39 tooth ring gear set or a good used set.

These differentials are rebuilt with all new bearings, cross pins, thrusts, collasible spacer, and seals. The "Core Charge" will be refunded after we determine that your old diff assembly is rebuildable. NOTE: ONLY THE LATEST STYLE BTA548/549 DIFFERENTIAL HOUSINGS WILL ACCOMODATE THE 3.9 CROWN WHEEL AND PINION. THE EARLY TYPE CASES WITH THE SIDE FILL PLUG ARE NOT REBUILD/CORE CANDIDATES FOR THIS GEAR SET AS HOUSING TYPES MUST MATCH - CORE GEAR RATIO IS NOT IMPORTANT.


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