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

[M3ZCPNYC]

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 Most likely the dealerships are replacing the gears to the superseded part numbers and replacing the crank hub bolt, I have not yet seen an invoice of a "repaired" SCH from a dealership to verify.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, I have decided on the vargas and will soon run e85 bc of it

[tom @ eas]

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.

Your situation would be ideal for getting these pieces installed beforehand. $3500 is much less than a replacement engine + labor. Without the SplineLock Hub, There is still a chance the timing gear can slip, causing a SCH. Especially with those running higher boost and no warranty or dealer assistance to fall back on.

IMHO, installing the Crank Bolt Capture without the SplineLock is not a 100% guarantee as this only keeps the crank hub bolt from backing out - it's intended to work in conjunction with the SplineLock Hub.

Originally Posted by M3ZCPNYC

thank you, I have decided on the vargas and will soon run e85 bc of it

Fantastic, enjoy your M3 worry-free with the benefits of E85.

[///BMW Junkie]

SCH video from an earlier thread. It appears with the repair, they went with their own version of the bolt capture.

https://www.h2motors.de/motorteile/b...raube/a-10643/

[MR RIZK]

Originally Posted by HMM

I picked up the Crank Bolt Capture, should arrive in a day or two. I'll see if the bolts line up for me. If not I'll wait until I can drop by a local place that specializes in BMWs and talk to them about the spline lock option. If I can get the bolt capture on I'll just rock it until my warranty is up and then go all out if I plan to keep the car.

Did they line up? If so how close was it to the extremities of the slot in the plate.

[overlook637]

Originally Posted by MR RIZK

Did they line up? If so how close was it to the extremities of the slot in the plate.

VTT says that most will line up. Those that don't line up will require the stretch bolt to be tightened, slighty. Or a new stretch bolt to be installed, this requires timing and crank lock tools.

[brad65ford]

so just read just about every post. one question.

Why the hell hasn't BMW address this and created a factory fix? Is it because they only want this motor to create just enough power any more will spin the hub indicating it was modified?

[Schultz28]

Originally Posted by brad65ford

so just read just about every post. one question.

Why the hell hasn't BMW address this and created a factory fix? Is it because they only want this motor to create just enough power any more will spin the hub indicating it was modified?

Because it's not a big enough issue. There really isn't a whole lot of cars it's happening to.

[FSociety]

Originally Posted by Schultz28

Because it's not a big enough issue. There really isn't a whole lot of cars it's happening to.

Not enough complaints

[Bluer2]

Originally Posted by brad65ford

so just read just about every post. one question.

Why the hell hasn't BMW address this and created a factory fix? Is it because they only want this motor to create just enough power any more will spin the hub indicating it was modified?

the only fix is a keyed crank hub...and that is an expensive recall. It was basically a design flaw that is why the new S58 engine has a keyed crank hub design now.

[hellrotm]

Originally Posted by Bluer2

...that is why the new S58 engine has a keyed crank hub design now.

Where did you get that info?

[hellrotm]

Originally Posted by Schultz28

Because it's not a big enough issue. There really isn't a whole lot of cars it's happening to.

Exactly, it is a fraction of a percent. Not anywhere near the scope of rod bearing failures of the S65/85.

[M-Pilot]

I have a question but I don't have a great mechanical knowledge so I'd appreciate if someone can explain it as simple as possible. Does spline lock hub have any disadvantages or risks compared to a pinned hub? I watched VTT's video and been reading pretty much every crank hub related thread for a while, and still not convinced if this "spline lock" method is safe for the crank (or other components). Since it always tries to lock itself more, does it not cause more and more stress (and potentially a failure in the long term)? Also, what if for some reason you wanted to take the hub out? Since it already locked itself, how would someone be able to remove it? Or is removing it after the install not possible?

After evaluating all the solutions, I came to the conclusion that I probably won't be going with a keyed hub design due to the cost. Call me crazy but I just cannot justify spending $4K for something that's very unlikely to happen. I got quotes for both bolt capture and spline lock with bolt capture installs, and they cost significantly less. I know bolt capture is not a 100% solution but might be sufficient for me since I won't doing anything more than stage 1 tune (most likely just the CS tune). Currently trying to decide between these two but I just want to make sure spline lock won't introduce a new issue in the future while eliminating the SCH problem.

[tom @ eas]

Originally Posted by cntzl

I have a question but I'm not a mechanic so I'd appreciate if someone can explain it as simple as possible. Does spline lock hub have any disadvantages or risks compared to a pinned hub? I watched VTT's video and been reading pretty much every crank hub related thread for a while, and still not convinced if this "spline lock" method is safe for the crank (or other components). Since it always tries to lock itself more, does it not cause more and more stress (and potentially a failure in the long term)? Also, what if for some reason you wanted to take the hub out? Since it already locked itself, how would someone be able to remove it? Or is removing it after the install not possible?

After evaluating all the solutions, I came to the conclusion that I probably won't be going with a keyed hub design due to the cost. Call me crazy but I just cannot justify spending $4K for something that's very unlikely to happen. I got quotes for both bolt capture and spline lock with bolt capture installs, and they cost significantly less. I know bolt capture is not a 100% solution but might be sufficient for me since I won't doing anything more than stage 1 tune (most likely just the CS tune). Currently trying to decide between these two but I just want to make sure spline lock won't introduce a new issue in the future while eliminating the SCH problem.

The benefits of the SplineLock design is the additional labor it saves (typically ~30hrs vs 20 hours) for the job, which involves crank drilling for the keyway. No additional stress is involved - the hub is in a fixed position once driven onto the crank. There's no need for removal, it's not considered a serviceable part.

The Crank Bolt Capture is only part of a complete solution - you need both the Crank Bolt Capture and The SplineLock to bulletproof your S55 from this issue, I cannot stress this enough as a replacement engine and labor will be much, much more.

If you plan on keeping your M3/M4 long term, do it. A lot of SCHs are not reported on modded cars due to BMW does read these forums from time to time (I spoke with a dealership a few weeks ago that had 3 in at the same time). I'm sure we'll start seeing more cases reported as miles rack up and warranties expire.

[M-Pilot]

Originally Posted by tom @ eas

The benefits of the SplineLock design is the additional labor it saves (typically ~30hrs vs 20 hours) for the job, which involves crank drilling for the keyway. No additional stress is involved - the hub is in a fixed position once driven onto the crank. There's no need for removal, it's not considered a serviceable part.

The Crank Bolt Capture is only part of a complete solution - you need both the Crank Bolt Capture and The SplineLock to bulletproof your S55 from this issue, I cannot stress this enough as a replacement engine and labor will be much, much more.

If you plan on keeping your M3/M4 long term, do it. A lot of SCHs are not reported on modded cars due to BMW does read these forums from time to time (I spoke with a dealership a few weeks ago that had 3 in at the same time). I'm sure we'll start seeing more cases reported as miles rack up and warranties expire.

I totally understand that the spline lock hub along with the bolt capture is the complete solution. I'm not claiming I'll be 100% safe with just the bolt capture. However, the info that I'm getting from my dealer as well as what's reported online tells me a different story. For example, there is not a single reported case of SCH at one of the largest dealers in Bay Area. Talked to two different SAs who I consider as friends. Another employee at the dealer has an F80 with over 700whp and been running just the bolt capture. In addition, SCH mostly happens to DCT cars. There are reported very few 6MT failures as well but I believe some of it (if not the majority) is due to money shift. These are the stats that I've collected over a long period of time after talking to several people and reading on this forum and this is what's leading me to do just the capture. Again, I 100% agree with you and by no means I'm trying to imply spline lock is a waste of money. I'm just thinking out loud at the moment and trying to make a decision while hoping to help others who are in the same situation.

[cbrtrx]

What would be an interesting test on the spline locks abilty to do as it states would be to see how easy the hub could turn if the bolt was left loose.

[tom @ eas]

Originally Posted by cntzl

I totally understand that the spline lock hub along with the bolt capture is the complete solution. I'm not claiming I'll be 100% safe with just the bolt capture. However, the info that I'm getting from my dealer as well as what's reported online tells me a different story. For example, there is not a single reported case of SCH at one of the largest dealers in Bay Area. Talked to two different SAs who I consider as friends. Another employee at the dealer has an F80 with over 700whp and been running just the bolt capture. In addition, SCH mostly happens to DCT cars. There are reported very few 6MT failures as well but I believe some of it (if not the majority) is due to money shift. These are the stats that I've collected over a long period of time after talking to several people and reading on this forum and this is what's leading me to do just the capture. Again, I 100% agree with you and by no means I'm trying to imply spline lock is a waste of money. I'm just thinking out loud at the moment and trying to make a decision while hoping to help others who are in the same situation.

There are much more DCT equipped M3/M4s on the road than 6MT, that's not really valid info to consider one transmission type any stronger than the other. Theories aren't really helping, and that's all that has been presented so far on the forums.

No one has a answer as to why this happens, only a clear solution as how to prevent it from happening.

[parabmw]

Any idea how many m4 m3 members on this forum?
Good chance if one has a sch issue it would be posted here.
I think it would be a good sample for the rate of failure.

[tom @ eas]

Originally Posted by parabmw

Any idea how many m4 m3 members on this forum?
Good chance if one has a sch issue it would be posted here.
I think it would be a good sample for the rate of failure.

You have to consider the forums make up a very small percentage of overall M3/M4 drivers.

We would most likely only hear from 100% stock drivers since there's no risk of warranty (with exception of a few cases). Dealerships (and BMW) have been known to skim through the forums and match screennames/locations with vehicles, so you will likely never hear from modded owners in fear of their claims being rejected.

[Bmwlmr99]

stage 2 tune and stage 1 full exhaust since 22,000...now at 58,000 ...no issues

[hz_diesel]

So it seems like the best route for doing the VTT kit and cut down the labor cost is to do the turbos at the same time. Sold.

[coldsteelrain]

I decided not to do the fix for now as I can't find anyone close by that has experience doing this stuff. If anyone is interested it's 600$ shipped in the cont. U.S. for this kit.

[COLOR="DarkRed"]SOLD[/COLOR]

[hz_diesel]

Originally Posted by coldsteelrain

I decided not to do the fix for now as I can't find anyone close by that has experience doing this stuff. If anyone is interested it's 600$ shipped in the cont. U.S. for this kit.

Hmm, guess I'll see if anyone in MA has experience with the VTT kit.