Crank Hub info

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Lieutenant
Nov 5, 2016
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As the crank hub problems get more, and more common, people need parts, since I am so familiar with these issues. I put together a little parts list, and also a little legend of what motors share what parts. Its a bit of a hodge podge, of what is shared between the platforms.

One thing to note is that after 2010. All the hub go to the 8 bolt hub, this continues all the way up to the new S55's. They do not use the same bolt, and some sprockets match some do not.

Overall i would say BMW was trying to save money by sharing parts, instead of coming up with a solution to fix the problem.

I can offer hope for all platforms. We are developing crank hub fix kits, and we will add these to our "Game Changer" line up to go with our Crank Bolt captures. For the average person the Crank bolt Capture is prob enough. For other that want to push the boundries, the full hub replacement, with the Crank Bolt Capture, may be the solution for you.
There is a PDF there for anyone who wants to download the reference.

CRANK HUB PART BREAK DOWNS_small2.jpg
 

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TWilly

Specialist
Jul 7, 2017
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Tyler
very good info tony thanks for sharing! any more info on why the crank hub bolt is coming loose (wrong torque?, ect). how common is this issue for N54s?
 
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titium

Private
Nov 8, 2016
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I'd never really heard of it until reports of the s55 crank hub spinning started coming out. Not saying it doesn't happen but I don't believe it's as common as is being made out.
 
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[email protected]

Lieutenant
Nov 5, 2016
596
606
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Bay Area
I'd never really heard of it until reports of the s55 crank hub spinning started coming out. Not saying it doesn't happen but I don't believe it's as common as is being made out.
Just because you do not believe it, doesn't mean it isn't happening. Some people also believe the earth is flat, doesn't mean it is. The issue is wide spread, and happening more, and more, and more as the cars get more milage on them.
 
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AK135i

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Dec 13, 2016
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The irony in this is incredible, this post comes out the day before my crank bolt spun its self out and buried my valves into my piston. I wish I had seen this a week earlier. :( I guess heres another one down for the books. On a brand new motor out of all things too. less then 300 miles on it.
 

AK135i

Corporal
Dec 13, 2016
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Anchorage, Alaska
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2010 135i
I would question whatever shop built you a new motor, and left the old hub, bolt, and gears on it. That is a MUST change when doing any motor.
That's exactly what im in the process of doing right now, I've spent so much money on getting it installed and buying an engine that has a warranty, so the engine is good. But im still down on cash after paying for labor only to have to do it again.
 

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Lieutenant
Nov 5, 2016
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Bay Area
Original files updated!

After getting with my BMW rep, he said a lot of the parts have superceded so this is easier than ever.

Basically N55/S55 are identical, all parts numbers can be interchanged.

N54 has its own hub, and bolt, everything else is the same.

So all sprockets the same, all grip disks the same, sprocket clip is the same across all three platforms. Makes this pretty easy.
 

AD-ENG

Corporal
Oct 22, 2016
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There is a variance in oil pump sprocket... early n54 use a sprocket and 2 grip disks with tangs. Later n54 (but before the hub change) use an oil sprocket with the 2 grip disks laser spot welded to it; all one part number.

I don't really have an option on which is better, but if you are replacing the sprocket it's easiest to get the new one with integrated grips. If you are reusing your early sprocket then you need to buy the appropriate early grips.

All later sprockets with integrated disks MUST be replace as a whole... it's the only way to run new grip disks.
 

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Lieutenant
Nov 5, 2016
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There is much more variance than that between old parts, and susperceded parts. The hub, the oil sprocket, the timing sprocket, the timing sprocket grip disk, etc. All are different. We didn't bother posting any old part numbers or designs. Really no point. You can't get them. If you try to order old parts they will just send you the new ones. If anyone is doing any crank hub work across all three platforms. The part numbers posted are what you need.
 

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Lieutenant
Nov 5, 2016
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606
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Bay Area
So to save $58 on a new hub you are ordering the old design they changed because they had issues with? Makes sense, I'm sure they were happy to sell you new old stock on parts want to get rid of... My parts manager at our BMW dealer wouldn't sell them to me, which I appreciated. At the time, I knew about a 1/4 as much as I do about the hub issues as I do now. I won't build any motor without 100% new hub parts across the board. Total price for everything is less than $150. Not the place to skimp on a motor build in my opinion.
 

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Lieutenant
Nov 5, 2016
596
606
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Bay Area
The oil sprocket grip disks from 07-09 have an old design that is more prone to slipping as they are not welded to the sprocket. The disk itself can slip. That's why they went away from this design. The new design won't work with old hubs, and vice versa. When I pull a motor apart. If I see the old hub, and parts I just toss it all in the trash, and replace it all with the new design, rather than trying to reuse the old hub, and get the old design sprockets, and grip disks. As I said total its less than $150 so worth the investment
 

AD-ENG

Corporal
Oct 22, 2016
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I'm not convinced new welded grid sprockets work any better. Those 5 spot welds leave 5 marks on the timing sprocket which indicates the welds are higher than the grip disk so as far as surface area for clamping it's not superior. It's also interesting that the s55 is prone to spin and uses the latest design. In my eyes these seems more like a production decision over a performance decision.

Knock on wood, I've never had one fail. Plus, the shear fact of how many failures (from the factory) vs the production numbers is extremely low.

Obviously a keyed sprocket assembly or something similar would be ideal.

Side question, is the new bolt any stronger than the old bolt when torque? I.e. the torque display is higher after the 100nm+360*