CBC is TRASH! Need recommendations

[Anarchy919]

It looks like the CBC and the hub bolt seem to be moving independently of the hub and taking the harmonic balancer with it. Time for a full upgrade and call it a day get the hub, new CBC and crank seal guard.

[TopJimmy]

Originally Posted by jfritz27

Indeed — for those who posted with issues, did you install yourself? What I'm getting at is whether you can confirm that the CBC was properly installed with all the bolts torqued to spec. If you had a shop install it, and let's say they didn't get everything to line up on the first try, instead of rotating it could they have said "F it" and just installed maybe 7 of the 8 bolts figuring it be would be OK (or maybe they tried rotating a couple times but still couldn't get it to line up)... but then over time that caused an imbalance, leading to this kind of failure... just thinking out loud.

This doesn’t happen. The CBC has slots so the bolts either line up first try, or you turn it one more sixth of a turn and re-seat, then the bolts line up. There’s never an install where some line up and others don’t.

[todd20]

These were installed by a reputable shop and all 8 were installed I checked when I got it. From my understanding the bolts got loose and came out over the course of 2-4 months. Once enough bolts came out of one side, the harmonic balancer started to get wobbly and started to grind down on the other bolts. This is why only two are stuck in the hub instead of all 6. Also this is a Lang racing 4 pin hub not a stock one

[b_w.]

Was locktite used on the install? Is this an issue of weak/shitty bolts or them backing out? Instructions clearly state to use locktite.

When I installed mine I recall reading some of the threads that guys were needing to install the bolts to 35 inch pounds instead of the 25 in the instructions to keep them from backing out...

[SflBimmer8484]

I've got three words for you. Insane Crank Hub

[chmura]

CBC is pointless. The crank bolt does not and cannot back off when torqued properly.

[Anarchy919]

Originally Posted by chmura

CBC is pointless. The crank bolt does not and cannot back off when torqued properly.

You’re a bit off, I’ve seen it first hand it can and will back itself out over time, heat cycles and torque of motor. Even if torqued to manufactures specifications and recommendation. Which is I believe 400 foot pounds.

[Track/S]

Originally Posted by Anarchy919

You’re a bit off, I’ve seen it first hand it can and will back itself out over time, heat cycles and torque of motor. Even if torqued to manufactures specifications and recommendation. Which is I believe 400 foot pounds.

This has already been discussed, there is no point in discussing this topic again, cbc crap is useless...

[Anarchy919]

Whatever helps you sleep at night to each his own I work in aviation, and if I could, I just stick some safety wire down in there and safety wire everything

[Info@mad-us.com]

Originally Posted by Track/S

This has already been discussed, there is no point in discussing this topic again, cbc crap is useless...

I understand it's a reverse thread so it's more likely the friction disc is falling apart creating that gap and allowing the bolt to become loose.

[Track/S]

Originally Posted by Info@mad-us.com

I understand it's a reverse thread so it's more likely the friction disc is falling apart creating that gap and allowing the bolt to become loose.

It is easier for the sprockets to move relative to each other than to loosen the bolt.
The thread is forward.

[Info@mad-us.com]

Originally Posted by Track/S

It is easier for the sprockets to move relative to each other than to loosen the bolt.
The thread is forward.

So its not reverse of the way the engine spins so it's always tightening sort of speak?

[Track/S]

Originally Posted by Info@mad-us.com

So its not reverse of the way the engine spins so it's always tightening sort of speak?

Exactly

[wheela]

I know bmw redesigned the joint to have bigger friction disks and bearing surfaces, but don't know the date they implemented it. Has any body heard of the new updated design hub spinning, or are all the hub spins out there on the original design?

[TractionControlDelete]

Originally Posted by wheela

I know bmw redesigned the joint to have bigger friction disks and bearing surfaces, but don't know the date they implemented it. Has any body heard of the new updated design hub spinning, or are all the hub spins out there on the original design?

A new bed plate design, a more abrasive disc surface, and revised/increased crank bolt torque specs was implemented in December 2015. Some owners have reported having the new bed plate on builds as early as June 2015 (but this hasn’t been verified).

See here for a poll of model year/specs/mods to get a sense of crankhubs that have spun:

https://f80.bimmerpost.com/forums/sh....php?t=1560274

[Beemerm3]

wow i just saw a n54 cbc spinning just like yours with the bolts torn off. thats so crazy i just got mine installed. hey at least u saved ur self from a messed up engine head, cam timing and all that. what next will u do with it? put a new stock oem crank hub and vtt cbc again? or drill out the holes again haha.

[todd20]

I told my buddy about this and he check it and sure enough two of his broke off as well…. everyone needs to check theirs if they have this junk installed as well.

Lucky Cody at s5x managed to extract my bolts out and saved my hub. NEVER will i use this again. Everyone just get a 4 pin hub and call it a day. I have a lang performance hub on mine

[JAI///M3]

Damn this is concerning. Glad you and your bud were able to dodge something worse here.

[TractionControlDelete]

Originally Posted by todd20

I told my buddy about this and he check it and sure enough two of his broke off as well…. everyone needs to check theirs if they have this junk installed as well.

Lucky Cody at s5x managed to extract my bolts out and saved my hub. NEVER will i use this again. Everyone just get a 4 pin hub and call it a day. I have a lang performance hub on mine

Thank you for posting these! I’m glad this information is getting out. What mods were on the car?

[wheela]

Originally Posted by TractionControlDelete

A new bed plate design, a more abrasive disc surface, and revised/increased crank bolt torque specs was implemented in December 2015. Some owners have reported having the new bed plate on builds as early as June 2015 (but this hasn’t been verified).

See here for a poll of model year/specs/mods to get a sense of crankhubs that have spun:

https://f80.bimmerpost.com/forums/sh....php?t=1560274

Thanks for sharing this link! Between this thread and all the others linked there it's been a ton of intersting reading. I still haven't gotten through all those other linked threads yet.

[ron_s55]

I checked mine today. Bolts aren't sheared, but tons of rust on the bolt heads.

I think it's because I used brake cleaner to clean the bolts before putting loctite. If I didn't do that, oils could protect it from rust.

It's been on for 1 year 2 months.

[chris719]

Originally Posted by Track/S

I said a long time ago that cbc is useless, in your case it has created even more problems, I wouldn't waste time trying to remove the broken bolts, mount a solid unit with 2 pins.

Do you not like the VTT spline lock? I admit, after seeing their CBC here, it does not inspire confidence in any of their products.