BMW M Gear Ratio Swap Set - M3, M5, M6, Z4M Differential Upgrade
BMW M Gear Ratio Swap Set - M3, M5, M6, Z4M Differential Upgrade, RacingDiffs part no. RD3051. A RacingDiffs part for differential rebuilds, gear ratio swaps and LSD setup.
Key Features
- Complete kit: All parts required for a precise, repeatable gear-ratio swap—no guesswork.
- Performance gains: Tailor acceleration and drivability to your use case (street, track, time attack).
- OEM-level precision: Components manufactured to meet or exceed OEM specifications.
- Guided install: Step-by-step tutorial + video walkthrough linked below.
What's Included
- Adjustment Shim Set: aligns and positions internal components correctly.
- Pinion Oil Seal: prevents leaks and maintains optimal lubrication.
- Large Pinion Bearing: required to install onto the new pinion from your new gear set.
- Crush Sleeve Shim: sets the correct pinion bearing preload.
- Pinion Position Shim Set (2.5–3.5 mm): precise pinion depth adjustment.
Technical Specs
| Spec | Value |
|---|---|
| Use case | Gear ratio change on BMW M differentials (see fitment variants below). |
| Pinion setup | Set pinion depth using the Pinion Position Shim Set (2.5–3.5 mm) and establish correct preload with the Crush Sleeve Shim. |
| Backlash | Adjust with the Adjustment Shim Set until backlash is within spec; verify gear contact pattern with marking compound. |
| Sealing | Install the new Pinion Oil Seal; lightly oil lips; ensure no nicks on yoke surface. |
| Torque notes | Clean threads; apply medium-strength threadlocker on ring-gear bolts; torque in a star pattern per BMW spec. |
| OEM references | Backlash adjustment shims: 33139065736 (33-13-9-065-736 / 33 13 9 065 736 / 33.13.9.065.736) 33139065737 (33-13-9-065-737 / 33 13 9 065 737 / 33.13.9.065.737) |
Fitment
Variant 1 (V1)
- E36 M3 (3.2 S52)
- E46 M3
- E28 M5, M535
- E34 M5
- E39 M5
- E24 M6
- E60 M5
- E63 / E64 M6
- Z4 M
Variant 2 (V2)
- E90 / E92 / E93 M3
Versions
| Model | Part number |
|---|---|
| E46 M3 ('00 - '05) | RD3051 |
| E46 M3 ('05 - '06) | RD3051 |
| E60 M5 | RD3051 |
| E63/E64 M6 | RD3051 |
| Z4 M | RD3051 |
Specifications
| Spec | Value |
|---|---|
| Brand | RacingDiffs |
| Part number | RD3051 |
| Weight | 2,1 kg |
RacingDiffs
Founded in Belgium, RacingDiffs is a specialist developer of limited slip differential conversions and upgrades for popular rear-wheel-drive platforms. Their bolt-in LSD kits convert open differentials into performance units without a full housing swap — a cost-effective solution for track day and drift enthusiasts seeking better traction and balance.
Official page: racingdiffs.com
Official page: racingdiffs.com
BMW M Gear Ratio Swap Set - M3, M5, M6, Z4M Differential Upgrade
258.94€
Excl. VAT: 214.00€
Tags: RS-RD-RD3051,