535 90-91 transmission types

[grave77]

Hi.. I was confused today when I was asking about a second hand auto transmission for my car ... been asked how many wires does it have 7 or 8 ?! any idea whats the difference ... and does the 525 tranny work on the 535 if I changed the front part? I need quick tips ... transmission is slipping like hell!!

[Kalevera]

The 535 uses the EH -- electrically controlled hydraulic -- 4hp, while the < '90 525s use hydraulic/non-electrical controls. What this means is: you can probably fit a non-EH trans onto an E34 M30 with the correct bellhousing, but you'll have the trans program error...either indefinitely or until the control module pins are jumpered as when doing a manual swap. You will probably also need to use some kind of kickdown cable -- winfred should know about that.

best, whit

[winfred]

the quick way i use to id a e32/34 m30 tranny is look at the switch next to the shifter, A M on 90 and up E S M on 89 and older usa cars, you need a tranny from a e32 735 e34 535 with the same switch. another option would be do the a-clutch repair which should fix it if it's just slipping, i did a page on it, it's in the engine and drivetrain section of this site. a 525 tranny won't really work, too much crap to screw with

[grave77]

well ... the problem is repairing the tranny is expensive and there is no garuntee that the valve body will function properly. my tranny is hard shifting when cold .. and mess up at the 3rd to 4th hanges untill it shifts with a hard shift ... then it vibrates at 100m/h if I stepped on the accelarator as it seems to slip and hold while driving ... 1st to 2nd it always hard shift ... so the tranny is f-up !! I dont really have that hope of fixing it. the idea why I wanted to use the 525 tranny is ... the Japanese specs tranny is shorter ratio as at 235Km/h the RPM is 6.25K, German specs is open to the 260Km/h with less RPM means less fuel consumption. the 525 tranny has the same 3rd and 4th ration ... thats the only reason. I couldnt find the German tranny in the scrap yard ... therefore I asked. I had an old friend who did the swap ... I liked the car, it was E32 735i ... but the OBC was a mess and the electricity too ... so I dont know what mess was in the OBC memory. if I was able to drop the tranny on the floor at home I would try the clutch repair but I will need a hydrolic jack up which I dont have.
how about transplanting a manual 5 speed tranny or 6 speed tranny? I heared that I will need a new drive shaft and clutch setup too ... I also need to disable the auto trans controller. ... any new tips? excuse my long reply :)