BMW Automatic to 5-Speed Transmission Conversion
This answer is applicable for many BMWs in addition to the one listed below.
Q I have a 89 635csi electronic automatic tranny with the sport, econo 3-2-1 selector. I am thinking about converting to a 5 speed manual tranny. In order to do the conversion, what parts would I need to do that, can you list all the necessary parts for me, please.
A
The earlier model BMWs are relatively straight forward to convert from an automatic transmission to a manual transmission. These models would be 3-series through 91, 5-series through 88, 6-series through 89, 7-series through 87 and the 2002, Bavaria and CS models. Later models can be converted in a similar manner. However, the check-control displays will show a transmission fault unless the instrument cluster coding plug is changed to a manual transmission model.
Here is a basic list of the parts that are needed, from the donor manual transmission car:
* Transmission
* Transmission mounts and crossmember (you should replace the mounts with new ones)
* Flywheel (perhaps a new original or a new light-weight unit)
* Pilot bearing (install a new one)
* Clutch assembly (obviously, a new clutch should be considered)
* Clutch hydraulics (master cylinder, slave cylinder and associated hoses & lines)
* Driveshaft (we’d recommend replacing the flex-disc and the center bearing)
* Complete shifter assembly (shifter support arm/plate and mounts as well as the shifter assembly itself. rebuilding the shifter with fresh original parts or a short-shift kit would be recommended)
* Clutch and brake pedal assembly
* Console shifter surround, boot and rubber floor sealing boot … and any other interior parts that may be different between the auto and manual models
Additional notes:
* The rear of the shifter support arm/plate will be supported, via a rubber mount, from the underside of the transmission tunnel by a bracket that is welded into the tunnel. The automatic transmission car may not have this bracket installed. You will have to remove the one from the donor car or fabricate one and affix it to the auto-trans car.
* On all but the latest model BMWs, you can remove all of the transmission wiring, switches and control units.
Comments are closed.
Can I use a 1985 donor car for my 1989 635csi? Will the getrag 265 crossmember mount the same as the 260, which was used in the ’89?
The transmission crossmembers are indeed different between the 85 and the 89 635csi models. Otherwise, much of the vehicle would be usable. The engine in the 89 is a later version of the M30 engine and does have a later Motronic operating system.