I have a 1979 528i manual. After finally getting it going it is clear to both me and the two mechanics that are helping me that the motor needs to be rebuilt. Instead of rebuilding the 2.8, I decided to do a b34 swap, it will cost less and add some power. So I went looking for an engine and another mechanic friend sold me a rather rusty '87 535i for a massive $100. The entire driveline is near perfect.
So my question is, if I take the engine and transmission from the e28 and put them in the e12, will either driveshaft be the right length or do I need a custom one? Also, how would I connect the speedometer as I believe that E28s have electronic speed sensors.
Thanks,
Gareth
Motor/Transmission swap question
-
garethashenden
- Posts: 54
- Joined: Sun Dec 27, 2009 10:46 am
- Location: New Hampshire
I should know the answer to the driveshaft question but I don't. Actually I can say this, your existing driveshaft will not work with the 535 tranny, it will be the wrong length. The 535i one might work in your car with the 535 tranny.
Getting a speedo to work is doable, but not real easy. You need to get a pulse transmitter hooked up, like E28s use in the diff, then run the wiring to the dash and then figure out what electronics the electronic speedo needs to work. Probably the cluster board and SI board out of the E28, but I'm not sure on that one. And you can't run the later engine, and it's electronics without a later bellhousing with the reference sensors in it. All of which is why the G265 tranny with a motronic bellhousing is so desirable.
Your options are to figure a way to run the speedo and possibly use the D/S or a custom one (a few hundred dollars) or convert the motronic engine to L-jet and use your current FI system. You would need to change the upper timing cover and use your distributor and use an adapter nut, but it's all very doable at a modest cost. The latter is what I'd probably do, although I have all the parts to do a motronic conversion and probably will at some time.
Or if you want to use the motronic and currently have a 4 speed you could bolt on a motronic bellhousing to it. And I do have one I'd be willing to part with if you decide on that route. Or if you happen to already have a 5 speed, this is definitely the way to go.
One more thing, if you're in California you need to keep it looking stock or else you will be required to go to a referee to smog it and be required to pass model year 87 smog standards.
Getting a speedo to work is doable, but not real easy. You need to get a pulse transmitter hooked up, like E28s use in the diff, then run the wiring to the dash and then figure out what electronics the electronic speedo needs to work. Probably the cluster board and SI board out of the E28, but I'm not sure on that one. And you can't run the later engine, and it's electronics without a later bellhousing with the reference sensors in it. All of which is why the G265 tranny with a motronic bellhousing is so desirable.
Your options are to figure a way to run the speedo and possibly use the D/S or a custom one (a few hundred dollars) or convert the motronic engine to L-jet and use your current FI system. You would need to change the upper timing cover and use your distributor and use an adapter nut, but it's all very doable at a modest cost. The latter is what I'd probably do, although I have all the parts to do a motronic conversion and probably will at some time.
Or if you want to use the motronic and currently have a 4 speed you could bolt on a motronic bellhousing to it. And I do have one I'd be willing to part with if you decide on that route. Or if you happen to already have a 5 speed, this is definitely the way to go.
One more thing, if you're in California you need to keep it looking stock or else you will be required to go to a referee to smog it and be required to pass model year 87 smog standards.
Mike W.
02 525ita. Wife's, aka grocery getter
02 530i. New to the fleet, 3 pedals.
03 QX4, AKA the Datsun. Finally got the 4WD vacationmoble to stop smoking.
07 Xterra. Still on the DL, a purchase from hell.
02 525ita. Wife's, aka grocery getter
02 530i. New to the fleet, 3 pedals.
03 QX4, AKA the Datsun. Finally got the 4WD vacationmoble to stop smoking.
07 Xterra. Still on the DL, a purchase from hell.
Hello Gareth,
The best way is to keep your old transmission, especially if it is 5-speed Getrag 265 (used in e12, some e23 and early e24 and some older e24). Also BMW have used for an year and a half or so this tranny on e28 models. You have to check the type of the donor e28 transmission. Usually e28 use Getrag 260, which is not so robust and strong as 265, which can handle to 600-700 hp. 260 is shorter than 265. This is important for the front part of the driveshaft. And 260's has no removable bellhousing, but 265 has. Some small length differences can be taken by the length of the grooves of the front part of the driveshaft (I think - not more than 1.5 cm).
If you have 4-speed transmission - again - look for the 265, even from later motronic versions. The only thing to do is to remove the speedometer gear from the old tranny and put it to the "new" one. Some new 265's are with blocked hole for the speedometer gear, but when you remove the protective metal cap - you can put the speedo gearshaft in this hole. The corresponding gear in the tranny is usually there. But if it isn't - you can use yours from the 4-speed box.
Your front part of the 4-speed driveshaft is equally longer to the front part of the 5-speed driveshaft PLUS the lenght of 5-th gear section of the 265. The 5-th gear section is about 10 cm.
Alexander
The best way is to keep your old transmission, especially if it is 5-speed Getrag 265 (used in e12, some e23 and early e24 and some older e24). Also BMW have used for an year and a half or so this tranny on e28 models. You have to check the type of the donor e28 transmission. Usually e28 use Getrag 260, which is not so robust and strong as 265, which can handle to 600-700 hp. 260 is shorter than 265. This is important for the front part of the driveshaft. And 260's has no removable bellhousing, but 265 has. Some small length differences can be taken by the length of the grooves of the front part of the driveshaft (I think - not more than 1.5 cm).
If you have 4-speed transmission - again - look for the 265, even from later motronic versions. The only thing to do is to remove the speedometer gear from the old tranny and put it to the "new" one. Some new 265's are with blocked hole for the speedometer gear, but when you remove the protective metal cap - you can put the speedo gearshaft in this hole. The corresponding gear in the tranny is usually there. But if it isn't - you can use yours from the 4-speed box.
Your front part of the 4-speed driveshaft is equally longer to the front part of the 5-speed driveshaft PLUS the lenght of 5-th gear section of the 265. The 5-th gear section is about 10 cm.
Alexander
-
garethashenden
- Posts: 54
- Joined: Sun Dec 27, 2009 10:46 am
- Location: New Hampshire
The car however was in california till 2000, then in MT for 6 years and ME for 4.