Drivetrain
BMW offered the E28 with both manual and automatic gearboxes. The torque is transmitted from the engine with a single-disc dry clutch with a torsional damper in the models with a manual gearbox, the automatic models have a torque converter with built in lockup-clutch.
Manual transmissions
The 5-speed manual transmissions are:
- Getrag 242 (for M10 and M20 engine models)
- Getrag 262 (M30 engines)
The 5-speed manual transmissions are:
- Getrag 240 (M10 and M21 engines)
- Getrag 245 (M10 engines)
- Getrag 260 (M20, M21 and M30 engines)
- Getrag 265 (M30 engines and 525e/528e)
- Getrag 280 (M88/3 and S38 engines)
- ZF S5-16 (M20 engines)
G260/5
Used on 5/6/733s from '83-'84. Non removable bell housing, waffle pattern for case casting. Considered weak and cannot accommodate a M5 clutch. Sheet metal shifter support. Overdrive 5th.
G260/5
Used on '83-'88 528es, and E30 6 cylinder cars.
Same model number as above, but different bell housing bolt pattern and shape, so it’s not interchangeable.
Some or most or all of the internal parts may be, but with the cost of used transmissions, it’s irrelevant.
Used sheet metal support thru about 86, then used the cast support. Waffle case pattern. Overdrive 5th.
G260/6
Used on '86-'88 535’s and E34 535s, but they may not have the flywheel sensor holes drilled out.
Identify it by the fins on the bottom of the transmission and non-removable case. Overdrive 5th.
G265/6
Used on '82 528e and '85 535i. Also on '85 6/735, '80-'81 E12, '81-'82 6/733s and E30 M3s.
Considered the strongest transmission available for E28’s.
Is easily identified by a removable bell housing which allows use on M10, M20 and M30 engines, as long as the correct bell housing is used or reused. All except M3s have a sheet metal shifter support.
It’s use in '85 M30 powered cars was reportedly dictated by the short life of the 260/5 in those cars. Overdrive 5th.
G280
Used on M5/M6s. Close ratio, but overdrive 5th gear.
G265/5
Never available on US spec cars, it's a close ratio 5 speed similar to the 265/6 overdrive transmission.
5th gear is 1:1. Often incorrectly called a 262 close ratio or dogleg, but a 262 is a 4 speed transmission.
All 265’s I’ve seen have the front case casting with a 262xxx casting number, but they are 265s if they are 5 speeds. Removable bell housing and it does have an unusual shift pattern with 1st being off by itself and 4th/5th across from each other instead of 5th being up by itself.
Most or all of the linkage parts seem to be model specific, the sheet metal shifter supports while they look the same, aren’t, even if from the same transmission and for the same chassis, i.e. one from a G265 from a 528e won’t work on a G265 in a 535i. I assume this is also the case for the later cast aluminum shifter supports, but I haven’t verified it myself.
Automatic transmissions
The 3-speed automatic transmissions are:
- ZF 3HP22 (M20 and M30 engines, US market only)
The 4-speed automatic transmissions are:
- ZF 4HP22 (M10, M20, M21)
- ZF 4HP22 EH (M20, M30)
3HP22
3 speed automatic used on all US spec BMW automatic cars from '77-'83. A very reliable and long lasting transmission, but only a 1:1 high gear. Bell housing specific, as I mentioned, they were used on many different models, with different bell housings. And Motronic cars need one with holes for the Motronic flywheel sensors. It requires a 3HP22 Motronic flywheel for Motronic cars, one off a 4HP22 will not work, it won’t bolt up to the torque converter.
4HP22
4 speed automatic. Again, used across the entire model line from '84 until at least the late '80’s. Has a quirk about burning out the “A” clutch pack if revved in neutral or park after it has been in any gear. Many feel it is a poor transmission, but I disagree, it seems to last longer than most automatic transmissions of it’s era, especially if taken care of, but it doesn’t tend to hold up as well as a manual. Outside of the aforementioned quirk, it seems to hold up well, especially in M20 powered cars. Like it’s predecessor, the 3HP22, it seems to respond well to regular fluid changes. While most are intimidated, it’s not a difficult transmission to work on, and if the somewhat infamous “A” clutch pack is the only repair required, it’s no more difficult than doing a clutch in a manual car. Like the 3 speed 3HP22, while it was used across the line, you need the correct one for the engine/bell housing if you are replacing one. Some have reported using a M20 transmission with a M30 bell housing and torque converter, and I have a good reference that says it works, but I haven’t verified it myself. Many of the “soft parts” meaning clutches and friction materials are the same as in the 3HP22. Not similar, but the same. It requires a 4HP22 flywheel for Motronic cars, one off a 3HP22 will not work, it won’t bolt up to the torque converter.
4HP22-EH
4 speed automatic, electronically controlled. Very similar mechanically to the 4HP22, but with solenoids making the shifts instead of hydraulics. Optional on M30 cars starting in '86, it has a choice of 3 different shift patterns, economy, normal and sport. Some feel it is better than the base 4HP22, some feel it is worse, my opinion is mostly it is just different. It does have a 3rd gear only “limp home” mode it can go into if there is a problem with the wiring or the ECU. It was used later E23 745i's, and 3HP22's on the early ones, so BMW had some confidence in it’s capability. It requires a 4HP22 flywheel for Motronic cars, one off a 3HP22 will not work, it won’t bolt up to the torque converter.Both the 3HP22 and 4HP22 can have the shift points adjusted somewhat by adjusting the cable on the throttle body going down to the transmission. Spec is something like .080” between the ferrule and the cable housing, but tightening it raises shift points, loosening it lowers shift points. Be gentle and make minor changes, but a minor adjustment can make a distinct improvement in how the car drives if it is shifting up too early. 5 speed conversions: Many here have converted autos to 5 speeds, and maybe a couple have even done the reverse. It's pretty straightforward, but you need all the bits, from the flywheel and flywheel bolts, all the way to the end of the driveshaft. And the pedals, and pedal bracket, and shift linkage and support. Ideally you will be getting everything from a single donor car so you can grab everything, but that isn't always possible.
Differentials
See Differentials.
Shifters
See Shifters.