Our '86 735 presently has about 53,000 miles. The gear selector has 3 options on the top of the transmission tunnel: S (sport); E (economy) 1/2/3 for manual. The S mode has 4 gears, while the E has 5, the fifth being an overdrive....problem: will not shift into fifth gear when selector is in E.......the S mode works fine (13 mpg). Dealer in Virginia Beach, Va. checked out car and advised that it appears to need a new selector switch.....estimated cost: $70 for the switch and 6 hours to install..They claim it is a difficult procedure requiring removal of the transmission tunnel to get at the switch. Has anyone done this procedure? Or have a similar experience? Have totally restored Lotus Elan, Seven and TVR.... Could it be something other than the selector switch? Any info would be appreciated...thanks...Bob Ross
Search, or ask over here: http://bimmerboard.com/forums/e23/ I have the same transmission in my '86 535i, and it's a 4-speed in "E" and 3-speed in "S" or 3-2-1.
I don't believe there is a 5th overdrive on that transmission. It's simply a 4 speed automatic that functions like John stated with 4th being overdrive in E mode.
I stand corrected: It is a 4 speed automatic transmisssion with S (Sport) and E (Economy). The manual transmission has a fifth gear. Dealer diagnosis is faulty selector switch. It remains in the S mode, will not change to E which would drop engine speed/ revs. significantly.... Estimated cost $70 for switch, 6 hours labor to complete the fix. Question is has anyone done this? What is the level of difficulty?
With no direct experience, I'd say you can probably do it yourself. This is the diagram from RealOEM.com: Part 5 is apparently the switch (list @ $65.09 on what may be an outdated list). The switch knob (Part 6) is attached to it but I don't know where it mounts. If you think you can get there in under six hours, then I'd say you can do it.
