Author Topic: JB Racing M20 flywheel - starter won't engage  (Read 2798 times)

07Lane40

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JB Racing M20 flywheel - starter won't engage
« on: July 07, 2017, 06:38:33 PM »
Well... I'm back.  Im trying to complete my M20 flywheel/clutch setup but the starter will not engage the flywheel. Woking with a 1991 318ic. the car was completely stock before i tore into it. a grenaded clutch is what drove me to do the swap.  I am using a JB Racing 8lb M20 flywheel for the swap.

So far I've tried the following setups from the block back:

Crank - spacer from m42 DMF - JB Racing M20 flywheel and stock M20 starter (remy reman)
Crank - spacer from m42 DMF - JB racing flywheel - m42 starter w/ pinion from M20 swapped
Crank - NO spacer - JB racing flywheel - m42 starter w/ pinion from M20 swapped
Crank - NO spacer - JB Racing flywheel and reman Bosch M20 Starter

The M20 starters were both for a 1990 e30 325i. is there a different year starter i should be using? Ive seen reports of fat tooth and small tooth starters. Both of my M20 starters have 10 tooth pinion gears. I can't find a listing for anything different.

Im at a loss.  The Bosch starter and no spacer has the most grinding/engagement but no dice. Ive jumped pins 11/14 in the OBD port and can verify the solenoid is engaging and pushing the pinion out. it will even grab enough to turn the flywheel 5-10 degrees and then nothing but grinding.

My final thought is to pull the trans back out and grind the housing down to get the starter further in to the flywheel. but with all of the reports of an easy swap from so many people I DONT GET IT!!

very frustrated at this point.  This is not my first build, not my first time wrenching on stuff.  BUT maybe I'm missing something obvious?! Can anyone else who has done this swap weigh in? especially if you have a JB Racing flywheel??

Thanks,
Lane


1998ccc

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Re: JB Racing M20 flywheel - starter won't engage
« Reply #1 on: July 08, 2017, 10:19:19 PM »
You can take the starter to Auto Zone or bench test to verify it's working properly and that the pinion is getting full travel.  The no spacer between the crank and flywheel is the normal way with these.

Any chance it's not a M20 flywheel, maybe for a different BMW etc.

07Lane40

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Re: JB Racing M20 flywheel - starter won't engage
« Reply #2 on: July 12, 2017, 12:11:01 PM »
You can take the starter to Auto Zone or bench test to verify it's working properly and that the pinion is getting full travel.  The no spacer between the crank and flywheel is the normal way with these.

Any chance it's not a M20 flywheel, maybe for a different BMW etc.

Thanks for the input, I'll pull it back out to bench test and see if it's getting full engagement.  When I ordered the flywheel I ordered direct from JB Racing so I assume they sent me the right one (phone order) but I'll double check the part number when I get the trans back out.

07Lane40

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Re: JB Racing M20 flywheel - starter won't engage
« Reply #3 on: July 17, 2017, 05:03:45 PM »
got the trans back out.. right flywheel. bench tested the starter and its functioning like it should be.

I'm stumped.

07Lane40

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Re: JB Racing M20 flywheel - starter won't engage
« Reply #4 on: July 17, 2017, 06:58:10 PM »
Got it figured out.

So.. I feel like an idiot. I misplaced the inspection plate/debris cover plate in my shop and didn't put it back in the first... second.. or third time around. So the 4th time pulling the trans I finally found the plate, put it back in and all is well. Turned out that plate perfectly lines up the starter to engage the flywheel.

So to anyone in the future doing this swap that stupid little plate that goes between the block and the bell housing IS NECESSARY!!!