blower snout wear and noise

[The Baron]

this snout has 600 miles on it. those are GROOVES worn in it from the spring loaded coupler i spoke about in the other thread.
just thought i would share..

[SamHouseIII]

Drive it till it breaks, then have GM replace under warranty.

[sportyb24]

That just makes me sick why they would not make a better part!!

[hognutz]

this issue puzzels me to no end. Is this an eaton or GM engineer that thinks this is acceptable?

[69NMYSS]

What purpose does the spring loaded coupler serve as opposed to a solid?

[DangerZL1]

It was explained in a past post that the wear in the displayed picture is normal by design and won't cause failure. I agree it isn't a good design, especially since the LS9 coupler fixes the problem, but neither GM or Eaton will do anything about it.

[The Baron]

no, tec the shaft the spring rides on does nothing.. but my caddy had enough metal worn off to make me think what a shitty idea.. that metal CAN work its way back into the needle bearing that the supports the rotor shaft.. i guess they figure as long as it lasts 100,000 miles its ok..

[SamHouseIII]

Not bashing but trying to gain an understanding of this...these marks are indentions from a spring? How so if a spring is used for tension? These are obivious Metal to Metal wear on the snout? Is the spring rotating? Why are the forward marks deeper?

It seems that this is caused by "snapping out of the throttle and i guess any idle surges" per the other thread?

Agree poor design, but more to this than we know.

[silverds]

Originally Posted by SamHouseIII

Not bashing but trying to gain an understanding of this...these marks are indentions from a spring? How so if a spring is used for tension? These are obivious Metal to Metal wear on the snout? Is the spring rotating? Why are the forward marks deeper?

It seems that this is caused by "snapping out of the throttle and i guess any idle surges" per the other thread?

Agree poor design, but more to this than we know.

A helical spring can be a compression shock absorber, an extension shock absorber, or a torsion shock absorber. Compression and extension primarily alter the length of a helical spring, while torsion alters the circumference the coils.

The spring used in the Isolator Coupling is a torsion spring so resistance is applied by twisting the helix around the shaft. Since force is applied to the helix asymmetrically, meaning at the outermost coils, the shaft keeps the spring oriented so that force is applied to the spring in the direction of most resistance.

As the helix constricts around the shaft, both the limited movement of the coils and the actual constriction of the helix cause friction between the coils and the shaft, leaving grooves in the softer metal.

The spring is limited in how "constricted" the coils can get by both the number of coils and by the range of motion permitted by the Isolator housing. So there is also a limit to how much damage can be done to the shaft by the friction.

The reason why the grooves are deeper at the end of the shaft is because that's where the variable forces are applied to the spring. That's where most of the work is done by the spring.

[69NMYSS]

Originally Posted by silverds

A helical spring can be a compression shock absorber, an extension shock absorber, or a torsion shock absorber. Compression and extension primarily alter the length of a helical spring, while torsion alters the circumference the coils.

The spring used in the Isolator Coupling is a torsion spring so resistance is applied by twisting the helix around the shaft. Since force is applied to the helix asymmetrically, meaning at the outermost coils, the shaft keeps the spring oriented so that force is applied to the spring in the direction of most resistance.

As the helix constricts around the shaft, both the limited movement of the coils and the actual constriction of the helix cause friction between the coils and the shaft, leaving grooves in the softer metal.

The spring is limited in how "constricted" the coils can get by both the number of coils and by the range of motion permitted by the Isolator housing. So there is also a limit to how much damage can be done to the shaft by the friction.

Wow, you either really know your stuff or a really good bs'er. Either way im impressed. Lol.

[silverds]

Originally Posted by 69NMYSS

Wow, you either really know your stuff or a really good bs'er. Either way im impressed. Lol.

I am definitely not a mechanical engineer so I suppose that would make me a good BS'r by default. However, I would put put my own money on my own words in this case.

I trust me, you should too.

[69NMYSS]

Originally Posted by silverds

I am definitely not a mechanical engineer so I suppose that would make me a good BS'r by default. However, I would put put my own money on my own words in this case.

I trust me, you should too.

Ill take your word for it

[OldScoolCamaro]

...yeah, I'm ignorant on the intricacies of the LSA and wear issues but from a mechanics standpoint after observing the photo as presented by the OP this is a stupid mechanaical design showing so much wear after a miniscule amount of run time, WTF didn't they resolve this years ago....just sayin...

[The_Raging_Bull]

I am baffled too as to why GM isn't getting a permanent fix in place in front of the curve on this one. If there's not a permanent fix, when mine goes, I'll have it replaced under warranty; then put the new SC on the shelf, and drop in an aftermarket Whipple and be done with it.

Since I'm planning on a home brew COPO; that would probably make for the strongest build too; just an extra 6 to 7K for an AX175 or an AX245 Whipple (2.9 L or 4.0 L).

One question, does the use of the Lingenfelter solid bushing
1. affect the warranty;
&
2. how hard is it to take of the spring loaded part and replace it with the LPE part?