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E34 M30 Engine Tranny Swap - Help

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    E34 M30 Engine Tranny Swap - Help

    Hi guys,
    I am planning on swapping the old M30 engine and tranny from the E34. I found a used engine and tranny already setup. Can you please send along your tips, advise or basic steps to follow? Your help is greatly valued. Thanks in advance.

    #2
    I followed this guide mostly.


    Garagistic has the engine brackets you need. Also get some polyurethane motor mounts from them.

    E34/E28 M30 manual trans should work. M20 manual will be at the wrong angle.

    Easiest driveshaft option is to get one for a 325es with the large guibo.

    You can use the M30 harness with no modifications, but it will be too short to reach the ECU unless you flip it around. You can also modify your M20 harness to reach the slightly different locations on the M30.

    Radiator from an E28 535i works great if you make a couple brackets for the bottom.

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      #3
      Here is a question for the more experienced:
      The transmission on the car is fine, great tranny...no slip, no lip.
      The engine that I bought for the swap has the tranny still installed on the engine.
      Should I unbolt engine and tranny and just drop in the new setup (which I've never tested) or should I unbolt both trannys and just swap the engine?
      What would you do? Why?
      Thanks

      Comment


        #4
        Whatever you do its much easier to install a gearbox and motor bolted together than either separately.

        I'd personally use your existing gearbox, if you know it works no reason to change it. keep the other one as a spare.

        Comment


          #5
          shoe horning it into the bay with the trans is doable but it puts the motor and trans at a very steep angle that I wasn't comfortable with and I was even using the shorter g240(m10) trans. You should take it apart anyway and inspect the rear main seal and do that with the motor out, also might as well do the flywheel/clutch/pp.

          Not sure what trans you have now but the m20 trans bellhousing does not match up to the m30 so throw that idea out of the window.
          sigpic

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            #6
            Both engines are M30 and both trannys are 4HP22.

            Comment


              #7
              I am unaware of anyone having done an M30 swap with the automatic transmission.

              You will be adding complexity with the extra electronics needed for the transmission and I can't speculate as to what the shifter linkage would look like, how well it would fit under the car, or what driveshaft you would need.

              Comment


                #8
                Just to clarify

                Sorry, my bad for not being very clear. I wanted to avoid becoming boring with 5000 details...

                The situation is as follows:
                - The donor engine/tranny setup is from a 1988 E32 735i M30 with the ZF 4HP22 automatic transmission - still bolted onto the engine. I've never tried the tranny or the motor from the donor car...But was told by prior owner that they ran great.
                - The car that needs an engine is a 1991 E34 535i M30 also with the ZF 4HP22 tranny.
                The tranny on the E34 was running great, close to perfect! But the engine was shot, head gasket was spewing oil something crazy. Too much work and $$ to rebuild.

                What should I do:
                - Yank out my engine and transmission as one piece and replace with my donor engine and tranny as one piece?
                or,
                - Separate my tranny from my engine, pull just the the dead engine..and then, do the same thing for my donor engine and just install the engine only? Leaving the original tranny and just using the donor engine.

                One question I have: (Say I change engine and tranny together) Will the driveshaft just bolt on correctly coming from an E32, going to an E34? Will that work or will I run into trouble there?

                Tell me what you'd do, please, and why you'd do it that way.
                Thanks in advance for your help.
                Last edited by Rockabilly_Rebel; 08-03-2017, 09:14 PM.

                Comment


                  #9
                  Originally posted by keyland View Post
                  I am unaware of anyone having done an M30 swap with the automatic transmission.

                  You will be adding complexity with the extra electronics needed for the transmission and I can't speculate as to what the shifter linkage would look like, how well it would fit under the car, or what driveshaft you would need.
                  I maybe didn't present the situation properly. It is an E34 that needs an engine, coming from an E32 that has trans/engine still bolted together.

                  Thanks for your input, I appreciate it.

                  Comment


                    #10
                    The e32 / e34 stuff should be identical as they are from the same era - the e32 transmission should just bolt right up to the driveshaft.
                    My e30: OEM+ with M30B35

                    Comment


                      #11
                      Originally posted by keyland View Post
                      You will be adding complexity with the extra electronics needed for the transmission and I can't speculate as to what the shifter linkage would look like, how well it would fit under the car, or what driveshaft you would need.
                      The 4HP22s are all the same (just some are hydraulic controlled, some electronic) - the bell housings are detachable, so in theory if someone wanted to do an M30 swap with an auto, they could just bolt the M30 straight up to the e30 trans with a simple bell housing swap.
                      My e30: OEM+ with M30B35

                      Comment


                        #12
                        If you're looking into getting the Garagistic mounts, CALL FIRST to see if they have them in stock. I ordered them on June 9th and didn't arrive until late July because they didn't have any stock. Since they just got a stock of them, you should be okay, but just a tip for you.
                        1986 325e Pearl White on Grey Houndstooth 24x,xxx miles M30b35 Swapped
                        2002 525i Jet Black on Sand Beige 13x,xxx miles
                        "This 2.5 liter inline six cylinder is smoother than my silk Versace underwear." -Vehicle Virgins

                        Comment


                          #13
                          Hi guys,
                          so after having done this job, I figured that I should answer a few (of my own) questions to pass it on to the next guy.
                          I went ahead and swapped the engine and tranny together, mostly because I didn't know what to expect if I separated them and seems that every time I take something apart on this car, I either break something or find out that (this part, that part and the other part) are 1 time use only and that means more $ and more wait time.
                          First off, the removal of the engine/transmission is fairly simple but it does take some time to label and remove everything carefully. The one point that sticks in my mind was the unbolting of the driveshaft/transmission -- TOUGH! They are bolted on at 7million torque and there is no space -- Get ready to swear! If you have crowfoot wrench things get better! Also, I had the rare 4 bolt, notched set-up, where the top of the stud has a notch in it to prevent it from turning and grooves at the base, which also prevent slippage. TAKE NOTE: These are 1 time use only. You CANNOT re-torque them to spec, They SNAP. (from experience). Reorder new bolts before as they aren't easy to find and may take some time before they get to you.

                          Everything bolted right in, without issue. The engine/tranny angle coming out and going in was crazy, almost vertical. To replace them together, you need an engine crane and angle adjuster.
                          So, that's the deal guys. Hope it helps!
                          Last edited by Rockabilly_Rebel; 12-30-2017, 06:58 AM.

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