Drivetrain
In total, seven transmissions were available for the various models of the E30: four manuals, and three automatics.
A 4-speed manual was available for the 316 and 318i (Getrag 220). The 316 and 318i also had the option of a common 5-speed manual (Getrag 240), while the 323i and 325i had a stronger 5-speed manual gearbox (Getrag 260). It is suggested that the 323i may have had a sports manual as an option and there are conflicting reports about whether the 320i was fitted with the Getrag 240 or Getrag 260. The Getrag 220 does not have synchromesh on reverse, however all other manual gearbox options have synchromesh.
The M3 was fitted with a Getrag 265 5-speed manual gearbox. This featured a dogleg shift pattern for European models and a standard H-pattern for North American models.
Both automatic transmissions were manufactured by ZF - they were the 3-speed 3 HP 22, which was available on the M10 316 and 318i models, and the 4-speed 4 HP 22, which was available on the 320i, 323i, 324td, 325, 325i and 325e models, as well as M40 powered 316i and 318i.
Transmission gear ratios:
| 4-speed manual | 5-speed manual | 3-speed automatic | 4-speed automatic | ||||
|---|---|---|---|---|---|---|---|
| available on | 316, 318i | 316, 316i, 318i, 320i | 323i standard, 325i | 323i sports | 316, 318i | 320i, 323i | 325i |
| 1st | 3.76 | 3.72 | 3.83 | 3.76 | 2.48 | 2.73 | 2.48 |
| 2nd | 2.04 | 2.02 | 2.20 | 2.33 | 1.48 | 1.56 | 1.48 |
| 3rd | 1.32 | 1.32 | 1.40 | 1.61 | 1.00 | 1.00 | 1.00 |
| 4th | 1.00 | 1.00 | 1.00 | 1.23 | - | 0.73 | 0.73 |
| 5th | - | 0.81 | 0.81 | 1.00 | - | - | - |
| reverse | 4.10 | 3.45 | 3.46 | 4.10 | 2.09 | 2.09 | 2.09 |
There were many differentials used on the E30 models. The 316 and 318i shared a differential, as did the 320i and 323i, with the standard transmission. 323i models with sports transmissions had a different differential. The 325i received its own ratio, as did the 325e. The various M3s had special ratios as well.
Differential gear ratios and types:
| model(s) | ratio(s) | case size | type(s) |
|---|---|---|---|
| 316 before 9/84 | 3.64 | small | open |
| 316 after 9/84 | 3.91 | small | open |
| 316i M10 | 3.91, 4.10 | small | open |
| 316i M40 | 4.27, 4.45 | small | open |
| 318i M10 | 3.64, 3.91, 4.10 | small | open |
| 318i M40 2- and 4-doors | 4.10, 4.45 | small | open |
| 318i M40 convertible and touring | 4.27, 4.45 | small | open |
| 318is | 4.10 | small | open (USA Spec had an optional 4.10 small case LSD) |
| 320i before 9/85 | 3.46 | small | open |
| 320i 9/85 to 9/87 | 3.64, 3.91 | small | open |
| 320i after 9/87 | 4.10 | small | open |
| 320i convertible and touring | 4.27, 4.45 | small | open |
| 323i before 9/84 | 3.23 | medium | open |
| 323i after 9/84 | 3.46 | medium | open |
| 324d | 3.45 | small | open |
| 324td | 3.25 | medium | open |
| 325i before 9/86 | 3.46, 3.73, 3.91, 4.10 | medium | standard - open
sports - mechanical limited-slip |
| 325i after 9/86 | 3.64, 3.73, 3.91, 4.10 | medium | standard - open
sports - mechanical limited-slip |
| 325i convertible before 9/86 | 3.46, 3.91 | medium | standard - open
sports - mechanical limited-slip |
| 325i convertible after 9/86 | 3.64, 3.91, 4.10 (USA SPEC) | medium | standard - open
sports - mechanical limited-slip |
| 325i touring | 3.91 | medium | open |
| 325ix 2- and 4-doors | 3.64, 3.73, 3.91, 4.10(US SPEC AUTO) | medium | open, all viscous, 10-100% limited-slip |
| 325ix Touring | 3.91, 4.10 | medium | open, all viscous, 10-100% limited-slip |
| 325, 325e US-models | 2.93, 3.23 | medium | standard - open
sports - mechanical limited-slip |
| 325e before 9/85 | 2.79 | medium | standard - open
sports - mechanical limited-slip |
| 325e 9/85 to 12/86 | 2.93 | medium | standard - open
sports - mechanical limited-slip |
| 325e after 12/86 | 3.25, 3.46 | medium | standard - open
sports - mechanical limited-slip |
| M3 (North America) | 4.10 | medium | mechanical limited-slip |
| M3 (Europe), Evolution | 3.25 | medium | mechanical limited-slip |
| M3 Convertible | 3.25 | medium | mechanical limited-slip |
| M3 Evolution II, Sport Evolution | 3.15 | medium | mechanical limited-slip |
The all-wheel-drive system on the iX models used three differentials to distribute power to the wheels, 37:63 split front to rear. The center and rear differentials use viscous couplings to split torque. The front differential was open.
Read more about this topic: BMW 3 Series (E30)