E28 M5 Diffsonline Stock Rebuild Differential (3.91, 2-Clutch)

This listing is for a E28 M5 differential rebuilt to stock specs by the experts at Diffsonline. No charts and data to ponder - if you just want your differential to perform as it did when new - or better! - this is your best option. Note that BMW no longer offers a new or rebuilt M5 differential so using an aftermarket expert is your best, and only, option.

This listing takes out all of the guesswork and research on buying a E28 M5 diff. The Diffsonline E28 M5 diff is rebuilt with the original gear ratio (3.91) and with a slightly improved 2-clutch limited-slip unit. Our rebuilt LSD units are quieter and last longer than the original factory builds. Polishing of gears and bearings is also available to improve service life and performance.

The rebuild process is extensive:

• The used diff is disassembled and cleaned
• The outside case (carrier) is stripped of grease, grime, and rust
• New OEM clutch discs and plates are assembled
• The gear set is assembled with the LSD
• Any machining of the carrier is done in-house
• New OEM bearings are fitted
• New OEM seals are fitted
• The entire internal assembly is aligned (crucial in avoiding gear whine later on)
• Final assembly and checks
• Carrier is given a fresh coat of black paint
• Shipment to your door in special heavy-duty packaging

A $2,500 core charge is not included in the the price and will be added during processing. We need your original diff returned so we can continue rebuilding diffs for other customers. Your original differential must be returned to Diffsonline within 14 business days. Only complete and reusable cores will be eligible for a refund (no blown out, abused, or modified cores please). You must return a diff equal in components and accessories to the one sent to you. You can avoid the core charge altogether by sending in your original diff to be rebuilt.

The diff you receive will be ready to install, minus the fluid and rear cover (which you remove from your original diff). We recommend Red Line 75W90 for street or 75W110 for light track use.

A core charge applies to this purchase. The supply of original parts for rebuilding keeps the final purchase price low. The core must match the part that was supplied in terms of fitment, type, application, accessories, and hardware. Damaged or modified cores will not receive a refund. A core charge can only be refunded once the core has been inspected and approved. Click here for our Core Policy.