M90 flywheel position issue?

Post here for mechanical and engine topics such as fuel issues, transmission problems, rough idle, exhaust, electrical issues, etc

Moderators: GRNSHRK, ron, bfons

Post Reply
msoft
Posts: 35
Joined: Thu Jun 30, 2022 1:48 pm
Location: Sweden

M90 flywheel position issue?

Post by msoft »

Yesterday I removed the flywheel from my M90 and didn't think of noting which position it was in. I assumed there were alignment pins but now when I look at my pictures, I see none. I understand that the position has to be right for the timing marks. I assume the bolt holes are symmetric. Any hints on how to verify correct position?
20220811_191046.jpg
20220811_191046.jpg (1.8 MiB) Viewed 591 times
User avatar
86_6series
Platinum Member
Platinum Member
Posts: 1069
Joined: Mon Apr 02, 2007 10:08 pm
Location: West Nyack, NY

Re: M90 flywheel position issue?

Post by 86_6series »

Look @ the 11:30 hole position in the flywheel. That is where the dowel gets inserted to clock it.

This is from an 85 but the system is the same, look @ # 7.

https://www.realoem.com/bmw/enUS/showpa ... Id=11_0313
86-635CSi
96-MB C220 SOLD
98-740i
71-Continental MK3
msoft
Posts: 35
Joined: Thu Jun 30, 2022 1:48 pm
Location: Sweden

Re: M90 flywheel position issue?

Post by msoft »

86_6series wrote: Fri Aug 12, 2022 10:44 am Look @ the 11:30 hole position in the flywheel. That is where the dowel gets inserted to clock it.

This is from an 85 but the system is the same, look @ # 7.

https://www.realoem.com/bmw/enUS/showpa ... Id=11_0313
11:30 hole position in my picture above? Not sure which hole and what it locks against?
User avatar
hornhospital
Platinum Member
Platinum Member
Posts: 2929
Joined: Sun Jul 11, 2010 6:46 pm
Location: Silverhill, AL
Contact:

Re: M90 flywheel position issue?

Post by hornhospital »

There's a thin steel bushing on the rear of the crankshaft (or should be) that fits in that hole at 11:30 in your picture. Its a hollow tube,, not a dowel. The flywheel bolt for that hole fits through the bushing. That's what times the flywheel to the crank so that the crank position sensor is correctly registered.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
User avatar
Ralph in Socal
Platinum Member
Platinum Member
Posts: 2745
Joined: Tue Apr 14, 2009 3:32 am
Location: High Desert of SoCal

Re: M90 flywheel position issue?

Post by Ralph in Socal »

hornhospital wrote: Fri Aug 12, 2022 8:44 pm There's a thin steel bushing on the rear of the crankshaft (or should be) that fits in that hole at 11:30 in your picture. Its a hollow tube,, not a dowel. The flywheel bolt for that hole fits through the bushing. That's what times the flywheel to the crank so that the crank position sensor is correctly registered.
+1. Ken is on point. #7 in the realoem diagram may be missing.

Ralph
There is a very fine line between "Hobby" and Mental Illness.

85 635csi Zinno Auto
84 528i Euro
83 635 Euro Arktik
81 528i Kastanien 5-speed
88 528e Bronzit (Granpa Car)
86 535i Auto (For Sale)
81 633 csi (retired)
msoft
Posts: 35
Joined: Thu Jun 30, 2022 1:48 pm
Location: Sweden

Re: M90 flywheel position issue?

Post by msoft »

Thank you! Now I see the hollow tube and the corresponding hole in the crankshaft mounting plate.
Post Reply