▀▄ eas | VTT "SplineLock" CrankHub Installation Overview for S55

[///BMW Junkie]

Originally Posted by Cleber T.

got mine installed about a month, so far so good with all kinds of abuse

How much in labor?

[blockdoc]

Originally Posted by ///FASTDAD

How much in labor?

20 hours for me. But there was no way I was going to upgrade turbos without doing the fix. Interestingly enough, mine had already apparently "spun" and had had a cheap fix done previously.

[///BMW Junkie]

Originally Posted by blockdoc

20 hours for me. But there was no way I was going to upgrade turbos without doing the fix. Interestingly enough, mine had already apparently "spun" and had had a cheap fix done previously.

By cheap fix, are referring to the VTT bolt capture or oem "fix"?

[blockdoc]

Originally Posted by ///FASTDAD

By cheap fix, are referring to the VTT bolt capture or oem "fix"?

Some sort of OEM fix. We are guessing BMW did something easy. Clearly there was no engine damage but it had clearly spun

[Proctor750]

I see VVT has both the hub AND a bolt capture. My understanding is that it's the bolt backing out each time which causes the break in friction - if the capture keeps the bolt from backing out - why get the hub?

[tom @ eas]

Originally Posted by Proctor750

I see VVT has both the hub AND a bolt capture. My understanding is that it's the bolt backing out each time which causes the break in friction - if the capture keeps the bolt from backing out - why get the hub?

SPH can happen as a result of the crank hub bolt backing out (or stretching) or friction discs are not being strong enough to remain locked together. Or even a combination of all three, no one can say for sure.

IMHO, installing the Crank Hub Capture kit without the 1-piece Crank Hub doesn't put you any safer territory.

[Proctor750]

Originally Posted by tom @ eas

SPH can happen as a result of the crank hub bolt backing out (or stretching) or friction discs are not being strong enough to remain locked together. Or even a combination of all three, no one can say for sure.

IMHO, installing the Crank Hub Capture kit without the 1-piece Crank Hub doesn't put you any safer territory.

Are there any known cases of spun hubs with using the bolt capture plate only?

[yjypm]

Originally Posted by Proctor750

Are there any known cases of spun hubs with using the bolt capture plate only?

No, since the sample size is too small. Not many people have installed the bolt capture only.

[Proctor750]

Originally Posted by yjypm

No, since the sample size is too small. Not many people have installed the bolt capture only.

I agree - there simply is not enough data.

I suppose my confusion stems from the fact that the locking plate has been around for a lot longer and made by the same company. I am wondering what spurred them on to decide it was not sufficient as a solution? It would seem to reason that they would only go for the nuclear option (spline lock) AFTER confirmed failures with the plate installed.

I also am starting to think this is not HP related but RPM related and as someone who intends to track the car on close to stock power - that worries me.

[evolved///M]

Has anyone checked the balance of the damper on a spun hub?

[yjypm]

Originally Posted by Proctor750

I agree - there simply is not enough data.

I suppose my confusion stems from the fact that the locking plate has been around for a lot longer and made by the same company. I am wondering what spurred them on to decide it was not sufficient as a solution? It would seem to reason that they would only go for the nuclear option (spline lock) AFTER confirmed failures with the plate installed.

I also am starting to think this is not HP related but RPM related and as someone who intends to track the car on close to stock power - that worries me.

They might have discovered a failure under internal testing, but they might simply release a new product (the hub) to make more money since the lock didn't make enough sales.

[M-Pilot]

Originally Posted by Proctor750

I agree - there simply is not enough data.

I suppose my confusion stems from the fact that the locking plate has been around for a lot longer and made by the same company. I am wondering what spurred them on to decide it was not sufficient as a solution? It would seem to reason that they would only go for the nuclear option (spline lock) AFTER confirmed failures with the plate installed.

I also am starting to think this is not HP related but RPM related and as someone who intends to track the car on close to stock power - that worries me.

Maybe they can answer your question

Tony@vargasturbotech Sales@vargasturbotech Chris@VargasTurboTech

[behindthen0thing]

I would be inclined to agree that it's more an RPM thing and not HP. Just thinking intuitively , the hub is turning the cam shafts correct? With increased power and tuning I don't really see the load needed to turn the cams increasing. What could happen though is maybe the engine is reving faster and more often.
Plus with the DCT which supposedly has more failure rates, the engine jumps rpms when shifting much faster and more often that traditional stick. This would cause more of a load on the hub as the engine is speeding up and slowing down through the changing momentum of the chain and cams at a faster rate, maybe slowly working the bolt loose or the hub to slip which then later can slip out when you're doing 40 mph with no load.
This is just my train of thought. I could be wrong

[tom @ eas]

Originally Posted by Proctor750

I agree - there simply is not enough data.

I suppose my confusion stems from the fact that the locking plate has been around for a lot longer and made by the same company. I am wondering what spurred them on to decide it was not sufficient as a solution? It would seem to reason that they would only go for the nuclear option (spline lock) AFTER confirmed failures with the plate installed.

I also am starting to think this is not HP related but RPM related and as someone who intends to track the car on close to stock power - that worries me.

Crank Bolt Captures have been around since the N54.

I don't see the Crank Bolt Capture alone as being sufficient, both the SplineLock Hub and Crank Hub Bolt Capture is an absolute precaution to a widespread problem. One possibility is the friction areas aren't simply strong enough to hold in the OEM design. Three areas can cause a SCH:

- Crank Hub Bolt not torqued properly or backing out
- Crank Hub Bolt has stretched/backed out
- Friction areas on hub/timing gear cannot hold on their own or as a result of #1 & #2

Drilling/Pinning the timing gear can weaken the gear, we've seen evidence of this in other threads. Going to a 1-piece solution is the best solution at this time (other than a custom 1-piece billet crank) as it eliminates any slipping possibilities from happening....... ever.

Here's the changes BMW has made in the crank hub area over the years. The 1st generation 476 friction disc is no longer used, no data as to why there were 2 different discs used throughout production.

Crank Hub Timing Gear Friction Disc
11237848476 SOP-2/17 (NLA), Old Timing Gear, non-integrated friction disc available separately (11237848476)
11238090136 SOP-Current, with integrated friction disc

Oil Pump Gear
11417589309 SOP-2/17 Old sprocket, non-integrated friction disc
11418091535 2/17-Current, with integrated friction disc

The VTT SplineLock Hub comes with the Timing Gear as part of the hub (no possibility of slipping) and the 535 Oil Pump Gear.

Oil Pump and Timing chains have also changed numbers during production, this can be due to different manufacturers or even design changes. Most likely the dealerships are replacing the gears to the superseded part numbers and replacing the crank hub bolt, I have not yet seen an invoice of a "repaired" SCH from a dealership to verify. No reported cases of a vehicle with a repaired SCH having the same issue twice, but there are claims of later production cars experiencing SCHs which may or may not have been covered.

As mentioned before, if you have no plans to mod and still under warranty - let the dealership handle things if you experience a SCH. This is an area for those keeping their M3/M4s long term or planning on modding. Some highly modded cars never experience a SCH, some 100% stock cars do. It simply depends on what your cost of peace of mind is.

[overlook637]

Originally Posted by tom @ eas

One possibility is the friction areas aren't simply strong enough to hold in the OEM design. .

Yet the OEM design simply works in most every M for thousands of miles.

My guess is improper installation from the factory. Dirty or greasy bolt threads gave improper torque on the bolt. Dirty or greasy friction discs. Improperly adjusted torque wrench during manufacturing.

Combined with a design that places the friction disc at near max limits.

[blockdoc]

Originally Posted by overlook637

Yet the OEM design simply works in most every M for thousands of miles.

My guess is improper installation from the factory. Dirty or greasy bolt threads gave improper torque on the bolt. Dirty or greasy friction discs. Improperly adjusted torque wrench during manufacturing.

Combined with a design that places the friction disc at near max limits.

And the fact that many on this forum have nearly doubled the torque/HP which the M4 was originally designed for

[Chris@VargasTurboTech]

Originally Posted by cntzl

Maybe they can answer your question

Tony@vargasturbotech Sales@vargasturbotech Chris@VargasTurboTech

Tom answered it perfectly, and quicker than me.

[MR RIZK]

Originally Posted by tom @ eas

Drilling/Pinning the timing gear can weaken the gear, we've seen evidence of this in other threads.

Tom, are you able to provide any links to the above excluding the TPG solution that has sustained failure. Just evaluating my options at the moment.

[tom @ eas]

Originally Posted by MR RIZK

Tom, are you able to provide any links to the above excluding the TPG solution that has sustained failure. Just evaluating my options at the moment.

Not aware of any other hub kits that have failed at this time.

[///BMW Junkie]

Originally Posted by tom @ eas

Crank Bolt Captures have been around since the N54.

I don't see the Crank Bolt Capture alone as being sufficient, both the SplineLock Hub and Crank Hub Bolt Capture is an absolute precaution to a widespread problem. One possibility is the friction areas aren't simply strong enough to hold in the OEM design. Three areas can cause a SCH:

- Crank Hub Bolt not torqued properly or backing out
- Crank Hub Bolt has stretched/backed out
- Friction areas on hub/timing gear cannot hold on their own or as a result of #1 & #2

Drilling/Pinning the timing gear can weaken the gear, we've seen evidence of this in other threads. Going to a 1-piece solution is the best solution at this time (other than a custom 1-piece billet crank) as it eliminates any slipping possibilities from happening....... ever.

Here's the changes BMW has made in the crank hub area over the years. The 1st generation 476 friction disc is no longer used, no data as to why there were 2 different discs used throughout production.

Crank Hub Timing Gear Friction Disc
11237848476 SOP-2/17 (NLA), Old Timing Gear, non-integrated friction disc available separately (11237848476)
11238090136 SOP-Current, with integrated friction disc

Oil Pump Gear
11417589309 SOP-2/17 Old sprocket, non-integrated friction disc
11418091535 2/17-Current, with integrated friction disc

The VTT SplineLock Hub comes with the Timing Gear as part of the hub (no possibility of slipping) and the 535 Oil Pump Gear.

Oil Pump and Timing chains have also changed numbers during production, this can be due to different manufacturers or even design changes. Most likely the dealerships are replacing the gears to the superseded part numbers and replacing the crank hub bolt, I have not yet seen an invoice of a "repaired" SCH from a dealership to verify. No reported cases of a vehicle with a repaired SCH having the same issue twice, but there are claims of later production cars experiencing SCHs which may or may not have been covered.

As mentioned before, if you have no plans to mod and still under warranty - let the dealership handle things if you experience a SCH. This is an area for those keeping their M3/M4s long term or planning on modding. Some highly modded cars never experience a SCH, some 100% stock cars do. It simply depends on what your cost of peace of mind is.

Thank you Tom for taking the time on this. For some of us less mechanically inclined, are you able to explain little more on why keeping the bolt in place and not allowing it to back out using VTT capture "doesn't put us in any safer territory"?

Is it that hypothetically using the capture, the bolt can become loose while still in there(hub) and then cause a SCH? If so, what are the chances of that?

I understand the capture might not be a 100% proof solution, even VTT clearly state that in the product description, however they also state that from their experience most issues occur from the bolt backing out and this "fix" leaves very little room for a SCH.

I'm personally out of warranty and going with a Stg2 E85 tune and would like to address the issue. My dilemma is to perhaps just do the capture at fraction of a cost(under $1000 parts&labor). While being aware of not having a 100% proof solution, going with only the capture might make risk vs cost sense - if I'd be covered for the "most part", compared to going with a full kit($3500+ parts&labor).

Am I looking at this the wrong way? Again, going back to trying and understand the chances of a SCH with just VTT capture? Thanks.

[Harpinc]

Originally Posted by ///FASTDAD

Thank you Tom for taking the time on this. For some of us less mechanically inclined, are you able to explain little more on why keeping the bolt in place and not allowing it to back out using VTT capture "doesn't put us in any safer territory"?

Is it that hypothetically using the capture, the bolt can become loose while still in there(hub) and then cause a SCH? If so, what are the chances of that?

I understand the capture might not be a 100% proof solution, even VTT clearly state that in the product description, however they also state that from their experience most issues occur from the bolt backing out and this "fix" leaves very little room for a SCH.

I'm personally out of warranty and going with a Stg2 E85 tune and would like to address the issue. My dilemma is to perhaps just do the capture at fraction of a cost(under $1000 parts&labor). While being aware of not having a 100% proof solution, going with only the capture might make risk vs cost sense - if I'd be covered for the "most part", compared to going with a full kit($3500+ parts&labor).

Am I looking at this the wrong way? Again, going back to trying and understand the chances of a SCH with just VTT capture? Thanks.

You're doing a STG2 E85 tune...
So $3500 now to fix it the right way or $1000 to do a possible fix? Easy decision for me. A spun crank hub may do no damage like mine did, or may trash the engine. Do you feel lucky?

[parabmw]

Originally Posted by Harpinc

Guys.. my hub should spun at 30mph constant throttle. No kick-down involved.

What message did you get...drivetrain malfunction?
Were you able to drive car afterwards?
Is it safe to or should it be towed to prevent further damage?