Metric Mechanic Differentials

Please see below for pricing

The purpose of a LimIted Slip Differential is to gain traction at the rear wheels when cornering or under slippery conditions. A MM Variable Limited and Adjustable Limited differential is design to maximize traction at the rear wheels without upsetting the handling, for increased cornering speed. MM differentials can take a 10% to 20% increase in torque.

Open – Open Differentials , VLS – Variable Limited Slip, ALS – Adjustable Limited Slip, M-GKN Visco-lok LSD

Open differentials
All Open or Limited Slip Metric Mechanic differentials are all blueprinted. Meticulously measuring the rolling torque of the pinion and carrier bearings. Along with measuring the back lash of the ring & pinion. All gears are cleared and peened with a mat finish for improved oil retention.
Variable Limited Slip differentials
The BMW factory 25% Limited Slip Differential is a Salisbury 2 disc LSD with a 25% lock up. With the spider gear pins walking up 45° ramp angles for both acceleration and deceleration.
Metric Mechanic’s Variable Limited Slip has a 35% lock up with 2 or 3 friction discs and uses a 30° ramp angle for acceleration with a 45° angle under deceleration. A MM VLSD will increase your cornering speed & exit acceleration out of a corner, over a conventional factory LSD.
Adjustable Limited Slip Differentials
Metric Mechanic’s adjustable Limited Slip Differential converts an open BMW differential into an adjustable Limited Slip differential. The limited slip is controlled by 4 preloaded friction discs.
The lockup is set up at 30% to minimize under steer. Increasing the  lock up, causes a car to drive straight and under steer. By simply removing the differential cover, adjustment to the limited slip can be made using an open end wrench and measuring the breakaway torque at the wheel. Simple!
M – GKN Visco-lok LSD
M models form 2001-on (except E39/M5)
This is a speed sensitive LSD used in the E46 and later M cars.
The stock BMW M – GKN Visco-lok 215mm LSD has 50# of breakaway torque that increases to 105# of rolling torque.
Metric Mechanic increases the breakaway torque to 65# and the rolling torque to 120#.
These differential use as long and short stub axle. The short stub axle, over time, will gets loose with radial play in the carrier. We replace the failed short axle, with a shorten and modify a long stub axle to fix the radial play.

Terms and costs
Once a customer order is written up, we require half down to get started.
The down payment can be done with a Visa / Mastercard / Discovery / American Express credit card, PayPal or certified check. There are the 2 ways to purchase a MM differential

  1. Metric Mechanic builds your ordered differential from a used differential  core. It takes about 3 to 4 weeks to complete the build. The balance is paid before shipping plus the core deposit and shipping. Once the differential is installed, your old differential can be shipped back to MM in the same box for your core credit.  Exchanging the differential minimizes down time and installation.
  2. Or the customer sends in their differential to be built. It needs to be drained and we can tell you the best way to box it up for shipping. We take half down when, we receive the differential, and the other half prior to shipping. It takes about 3 to 4 weeks to complete the build. This method is commonly used when doing a restoration.

A core is a used engine, transmission, or differential that is rebuildable. Core deposits is not a set cost and is subject to change; based on availability, condition, and cost. The cores, we need, are for Classic BMWs that are 15 to 50+ years old. BMWs this old are very scares in salvage yards, many of the cores are too far gone to be rebuildable, and the rarer the core, the more the price goes up.
We buy use cores from suppliers or customers. Anymore, we will not waste a lot of time trying to find cores. We appreciate customers that are willing to supply their own cores.
After installation, the return differential core can be sent back in the same shipping box.
Returned cores must be rebuildable to get a full refund or pay a penalty for the damaged core.
If you’d like more details or would like to order, call 573 765 1269 MM Shop number from 9 am to noon and from 2 pm to 5 pm CST.
Or Jim’s cell at 573 836 4033 from 9 am to 8 pm CST.

168 Differentials

for Models with 4 Cylinder Engines
ItemPriceCore Deposit
Models: 2002, 2002ti, 320i
D1 - MM Open 168 Differential from '71 ≥ 76$1,600$600
D2 - MM VLS Variable Limited Slip 2 Disc Differential$3,400$600
D3 - MM ALS Adjustable Limited Slip Differential$3,000$600
Available Gear Ratios: 3.45, 3.64, 3.91, 4.10, & 4.45
Gear Ratio Change Upcharge
M42: (E30 318is '90-'91), (E36 '92-'95), (Z3 '95)
M44: (E36 318ti '96-'98) (Z3 '96-'99)
4 Cyl DOHC Engines
D4 - MM Open 168 Differential from '71 ≥ '76$1,600$600
D5 - MM VLS Variable Limited Slip 2 Disc Differential$2,200 Customer supplies rebuildable Limited Slip Core
D6 - MM ALS Adjustable Limited Slip Differential$2,500$600

188 Differentials

for Models with 6 Cylinder Engines
ItemPriceCore Deposit
Models: 2800 & 3.0 CS/Csi (E9), Bavaria, 3.0/3.0Si
side loader differential with 8 bolt carrier
D10 - MM Open 188 Differential, 8 bolt carrier, 3.64 gear ONLY$2,300$600
A gear change or limited slip, requires a side loader differential with a 10 bolt carrier.
SEE BELOW: Open 188 Differential with 10 bolt carrier.
Models: 5, 6, & 7 Series 1977 ≥ 1981
side loader differentials with 10 bolt carrier
D11 - MM Open 188 Differential
with a 10 bolt carrier
D12 - MM ALS Adjustable Limited Slip Differential$3,500$1,000
Available Gear Ratios 3.07, 3.15, 3.25, 3.45, 3.46, 3.64, 3.73, 3.91, 4.10 gear ratios
Gear Ratio Upcharge
$450 - $750
Models: 3, 5, & 6 Series from 1982 on, 3 Series E30 & E36, 5 Series E28 & E34
and 6 Series E24
D13 - MM Open 188 Differential$1,700$750
D14 - MM VLS Differential
Variable Limited Slip with 3 Disc
D15 - MM ALS Differential
Adjustable Limited Slip
Available Gear Ratios: 2.79, 2.93, 3.07, 3.15, 3.25, 3.45, 3.46, 3.64, 3.73, 3.91, 4.10
Gear Ratio Upcharge

210 Differentials

for Models with 6 Cylinder & V8 Engines
ItemPriceCore Deposit
Models: E28/E34 M5 & E24/M6 & Euro M5 1985 ≥ 1991 E39/M5 1999 ≥ 2003
D16 - MM 210 VLS Differential
Variable Limited Slip
$3,500Customer supplies rebuildable Limited Slip Core
Models: E46 M3 2001 ≥ 2006, Euro E36 M3 with 6 Cyl Engines
D17 - MGKN Visco-lok LSD Differential
with stub axle upgrade
$3,500Customer supplies rebuildable Limited Slip Core
E39/540 & Z8 with V8 Egines
D18 - MM Open Differential$2,000