FYI/DIY – M30B35 starter install and stud swap

[Hit Man X]

Well we all know the horror stories regarding the removal of the SR41X starter on the early M30s, so I will spare this write up that information. All that you really need for that a good set of metric half moon wrenches. Simply call up your local Cornwell dealer (or your preferred tool manufacturer) and order up a set. I do highly advise removing the lower intake plenum brace for starter R&R regardless of which style you use. It should be a 13mm at the motor mount bracket and a 10mm at the plenum itself (this is off memory and it is lacking, so please forgive me)

So why install studs in lieu of the factory M10x25 bolts? Ease of install and ease of removal if necessary in the future. Think of mounting a wheel on a vehicle with wheel studs, like your domestic pickup truck, as opposed to lining up the holes and starting the lug bolts on your E23. Plus the top nut is easier to remove.

What is so great about this starter? It is a permanent magnetic gear reduction starter. It has more cranking power, less weight, and easier to install. Oh and no more spade connection to engage the solenoid. What is not to like?



Items needed to perform this operation:
2 – M10 studs, roughly 40mm in length. Pitch was fairly coarse, probably 1.25. Bring one of the old bolts with you to the hardware store or just measure the pitch and order the studs online if you prefer.
2 – M10 nuts, these are to tighten the starter into place.
2 – M10 washers
1 – SR441X starter, this is found on the M30B35 and potentially other BMW models. Just order one from an E32 735iL. Be sure to have this bench tested PRIOR TO INSTALLATION.
1 – 10-12 gauge heat shrink ring terminal, roughly 3/8” lug. This is due to the fact the black/yellow wire that sends 12 volts from the ignition switch into the starter solenoid has a spade terminal that loves to fall off on the SR41X equipped vehicles. Now you have a far more positive means to lock that wire in place. This alone makes the SR441X starter swap a smart move.



Step 1 – Make sure you have the tools, knowledge, and ability to pull this off. It requires some modification to the vehicle. This assumes you have at least a decent idea of what you are doing when it comes to things automotive and understanding I am absent minded and probably left something out. These are the highlights of the install. If in doubt, seek out professional help.

Step 2 – Disconnect your battery terminals and remove the thing. Toss it in the trunk or somewhere else.

Step 3 – Notate the wire routing of the cables on the SR41X starter how you see fit. Masking tape, steno pad, photographs, whatever. Also while in there, go ahead and inspect all of your charging cables.
If they are in poor shape, this is a great time to replace them.

Step 4 – Remove lower intake brace. This is not absolutely necessary, but sure makes life easier if you have large hands or arms. Removal frees up quite a bit of space. Your call, flip a coin or throw some dice to let fate decide if you need.

Step 5 – Remove the old starter.

Step 6 – Verify threads are in good condition in the block and if so, install the studs. Unless you have a set of stud removers and installers, you will just need to use the double nut trick. Tighten two together and use the outer one to install the stud into the block until it bottoms out. Repeat for the other.

Step 7 – Test fit the new SR441X starter and if it drops in fine, toss the washers on the studs and run the nuts down by hand. Now use your tools to tighten the nuts to spec. See FSM or Bentley.

Step 8 – Reinstall the power cables per your notes earlier and modify the solenoid wire (black and yellow) accordingly.

Step 9 – Reinstall the intake plenum brace and anything else you have removed along the way including the battery.

Step 10 – Give your vehicle a test crank and enjoy the new starter.

Here is the SR41X (old style) –



Here is the SR441X (new style) –




Ring terminals –





Studs installed –




Starter installed –

[DesktopDave]

Excellent write-up, as usual. Timely too, I'll be swapping an M30 in the not-too-distant future. Might as well do the upgrades while it's out. Starter, different pulleys, maybe an alternator...it's great to know about all the incremental improvements BMW made as the M30 was produced.

[Area52]

Another great contribution from a stand-up guy. Thank YOU!

[Hit Man X]

Not my best work, but hope it clears up any questions for guys considering this modification.

[1981320i]

Not my best work, but hope it clears up any questions for guys considering this modification.

Thanks dood! Adding this onto the to-do's for 2015

[cargeek733]

Does this mod work on the early, L-Jet equipped E23s?

[cargeek733]

Only reason I ask is because of the wire that runs from the starter solenoid to the ballast resistor on L-Jet E23s...wondering if the B35 starter solenoid would play well with the resistor

[BONDOSPECIAL]

Another question about this swap. I sourced an SR444x starter from an e32/e38 V12 application. Do you know if this will work equivalent to the SR441X on my M30? I looked at pictures of the SR441 and 444 side by side and it looks like the 444 has a beefier motor on it. I wonder if it will otherwise work.

[motohunter4]

I did this when my starter crapped out 5 or 6 years ago. Taking the original out sucks.

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