|
Post Reply |
|
Thread Tools | Search this Thread |
10-03-2015, 04:56 PM | #67 | ||
Colonel
1204
Rep 2,818
Posts |
Quote:
|
||
Appreciate
1
|
10-03-2015, 05:16 PM | #69 |
Sameet
740
Rep 2,541
Posts
Drives: AY/B M4 '15
Join Date: Apr 2010
Location: Long Island, New York
|
As Taimur said, if this happens on stock cars to begin with, a tune and downpipes are irrelevant. Even the bearing problem on E9x M3's happen on stock cars. Plus, if you're getting warranty work to begin with, I would hope you take out the tune and downpipes before going into the dealer. You must not be very smart if you're going to go into the dealer with mods.
|
Appreciate
0
|
10-03-2015, 06:07 PM | #70 | ||
Lieutenant
253
Rep 551
Posts |
Quote:
Quote:
Unfortunately, the people who have the early failures will commonly find the blame placed on their modifications. It's not until BMW recognizes the problem and issues a fix will this be universally covered under warranty. The first E46 M3 owners with spun rod bearings had to pay out of pocket for repairs. |
||
Appreciate
0
|
10-03-2015, 06:10 PM | #71 | ||
Sameet
740
Rep 2,541
Posts
Drives: AY/B M4 '15
Join Date: Apr 2010
Location: Long Island, New York
|
Quote:
|
||
Appreciate
0
|
10-03-2015, 07:04 PM | #72 | |
grand poobah
254
Rep 2,253
Posts |
Quote:
Unfortunately as Reid alluded to, I think we all know that won't stop BMWNA from trying to make the argument that it's related to the mods or abuse initially but, if stock cars start/continue to experience this issue in any significant numbers BMW will have to address it. Last edited by hotrod2448; 10-03-2015 at 07:10 PM.. |
|
Appreciate
1
|
10-03-2015, 07:21 PM | #73 | |
Colonel
2634
Rep 2,809
Posts |
Quote:
To my knowledge, there have been several cases of bone-stock S55s that have had this failure. Power output has little to do with this failure. It is a design flaw, plain and simple. I don't really know of any manufacturer that doesn't use a keyed or otherwise locked crank/timing gear. The reason is simple, if it slips, things will break (on an interference engine, such as most modern internal combustion engines). BMW needs to address this. They would have a really hard time not proving they made a mistake in the design of this crank hub in a class action suit. They are basically going against industry standards by not using a keyed hub. |
|
Appreciate
0
|
10-03-2015, 07:25 PM | #74 | |
Captain
231
Rep 656
Posts |
Quote:
Honesty is always the best policy.
__________________
///M4 | AKRA Evo & DP's | Brembo GT BBK | MSR CAI & CP's | MPSC2 |
Suspension : | KW CS 3-way | Dinan Toe Links | GC ARWJ & End links | IND Shims | SPL Control arms & End links | aFe Bars | |
|
Appreciate
0
|
10-03-2015, 07:34 PM | #75 | |
grand poobah
254
Rep 2,253
Posts |
Quote:
|
|
Appreciate
0
|
10-03-2015, 07:42 PM | #76 |
Lieutenant General
2148
Rep 10,176
Posts |
There is no cost to this at all. Indexing a part costs nothing to a supplier and to BMW. I think that if this really is a problem, that it is a design flaw on unexpected additional torque.
|
Appreciate
0
|
10-03-2015, 07:54 PM | #77 | |
grand poobah
254
Rep 2,253
Posts |
Quote:
I'm guessing they thought it was a good way to simplify the parts/assembly and save a few bucks in an area no one would even care about... until they started jumping time. |
|
Appreciate
0
|
10-03-2015, 08:00 PM | #78 |
Colonel
2634
Rep 2,809
Posts |
When you say "additional torque", what do you mean exactly? If by saying "additional torque", you're referring to a modded S55, this issue has happened on some stock S55s. The stock S55 already makes a good amount of torque. Enough to warrant a keyed crank hub. Engines with far less torque have keyed or locked timing gears. It's just common fucking sense. Otherwise, it is a ticking time bomb.
|
Appreciate
1
Alexis@psi1.50 |
10-03-2015, 08:16 PM | #79 | |
Sameet
740
Rep 2,541
Posts
Drives: AY/B M4 '15
Join Date: Apr 2010
Location: Long Island, New York
|
Quote:
One person detonated with the JB4 compared to how many? Go back to your corner where you came from before you try to stir up some more shit. This is about the crank hub problem, not the JB4. |
|
Appreciate
1
|
10-03-2015, 08:41 PM | #80 | |
Joint Chiefs of Staff
4920
Rep 115,999
Posts |
Quote:
Mike |
|
Appreciate
1
|
10-03-2015, 08:50 PM | #81 | |
grand poobah
254
Rep 2,253
Posts |
Quote:
So regardless of the power the engine is making as long as you aren't doing things like altering cam profiles, valve spring rate, increasing the red line or to a lesser extent possibly altering cam timing or VANOS (which I don't believe any tunes currently do) there should be no real changes in the forces seen here from stock to tuned. |
|
Appreciate
0
|
10-03-2015, 09:22 PM | #82 | |
Colonel
2634
Rep 2,809
Posts |
Quote:
You can't make the engine rev faster in gear than you can in park or neutral. The timing gear would see more forces from a out of gear rev than an in-gear pull. |
|
Appreciate
0
|
10-03-2015, 09:23 PM | #83 | |
Colonel
2634
Rep 2,809
Posts |
Quote:
|
|
Appreciate
0
|
10-03-2015, 10:18 PM | #84 |
Lieutenant
448
Rep 469
Posts |
Does anyone think of load having a force on the gear? Rather than a calculated torque number based on dyno output, what is the load placed on this gear during a 4th or 5th gear dyno pull.
|
Appreciate
0
|
10-03-2015, 11:56 PM | #86 | |
Colonel
2634
Rep 2,809
Posts |
Quote:
The force applied to the gear is greater than the clamping force from torque applied from the bolt. This is obvious. But this has nothing to do with the amount of torque the engine is exerting on a clutch. The crankshaft is what is driving the crank hub, which has the timing gear pressed on to it, held together in place by the torque of the crank hub bolt. The timing gear drives the cam shafts via a chain. The torque from the engine IS overcoming the torque applied to the crank hub via the bolt. But what I'm saying is, the force applied to this timing gear would be just as great or greater in a neutral rev where the acceleration is much greater. The camshafts aren't providing much resistance to that timing gear, unlike the amount of resistance the drivetrain is exerting on the clutch, that the engine torque must overcome to cause the clutch to slip. With the engine directly tied to the drivetrain (in gear pull), the crankshaft is directly connected to the wheels (as long as the clutch isn't slipping). The acceleration would be much slower on the crank hub assembly than a free rev (neutral) and thus, in mind, the forces exerted on that hub assembly would be lower. Last edited by CaryTheLabelGuy; 10-05-2015 at 07:55 AM.. |
|
Appreciate
0
|
10-04-2015, 03:10 PM | #87 | |
Captain
231
Rep 656
Posts |
Quote:
Why, because I think JB4 is at the heart of most of these issues. Where ever an issue is, you seem to find a removed JB4. Just noticing.
__________________
///M4 | AKRA Evo & DP's | Brembo GT BBK | MSR CAI & CP's | MPSC2 |
Suspension : | KW CS 3-way | Dinan Toe Links | GC ARWJ & End links | IND Shims | SPL Control arms & End links | aFe Bars | |
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|