Is this normal (LSA TVS1900 question)?
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Teching In
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From: Central Indiana
Is this normal (LSA TVS1900 question)? My CTS-V has a supercharger-related rattle; it's not the marbles-in-a-can thing, mine's a 2014 with the factory solid coupling.
There's some lash/play in the drive - it's not much in terms of angular displacement, but it's enough to make noise when you twist the pulley back and forth...is this typical?
Video
There's some lash/play in the drive - it's not much in terms of angular displacement, but it's enough to make noise when you twist the pulley back and forth...is this typical?
Video
Thread Starter
Teching In
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From: Central Indiana
I don't understand.
There will always be play in gearsets, the teeth can't mesh perfectly. It can be close enough to be imperceptible, which clearly is not the case here. I wondered if all 1900s are like this, or is mine just at the loose end of tolerance stack?
There will always be play in gearsets, the teeth can't mesh perfectly. It can be close enough to be imperceptible, which clearly is not the case here. I wondered if all 1900s are like this, or is mine just at the loose end of tolerance stack?
Thats a perfect example of a shot coupler. Bearings are fine. The gearset is precision machined, you will not feel the miniscule slop in the mesh, esp not a SC that new
To fix that you need a bottle of SC oil and the coupler which is $30 off ebay. Wear thick dishwasher gloves because you dont want that oil on your skin, you will smell like a port-a-john. Its a simple R&R, OEM couplers are often spring loaded dampers which develop play quickly
To fix that you need a bottle of SC oil and the coupler which is $30 off ebay. Wear thick dishwasher gloves because you dont want that oil on your skin, you will smell like a port-a-john. Its a simple R&R, OEM couplers are often spring loaded dampers which develop play quickly
Thread Starter
Teching In
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From: Central Indiana
It's not the coupler. I'm pretty sure it's not bearings, but I can't say that with total confidence. Although I think if the bearings were bad I'd see rotor interference.
First of all, the TVS units are sealed - the oil's in the back, you don't have to drain when you pull the snout.
Second, this coupler is perfect. It's sitting on my desk right now. There was no play in its fit. I put an LPE coupler on and got the exact same results.
The only thing left is slop in the gearset.
GM has now put out a PIP on this, FWIW, and of course..."it's normal".
First of all, the TVS units are sealed - the oil's in the back, you don't have to drain when you pull the snout.
Second, this coupler is perfect. It's sitting on my desk right now. There was no play in its fit. I put an LPE coupler on and got the exact same results.
The only thing left is slop in the gearset.
GM has now put out a PIP on this, FWIW, and of course..."it's normal".
Easy way to know for sure is to pull the snout off and wobble the gears back and fourth. Rotors are machined with extreme tolerance. If the gearset was out even slightly, rotor wear would be obvious
Bearings sound horrible with the engine running and have a "dragging" feel when spinning the unit by hand. They do not give slop like that, doesnt matter how shot they are. Besides, they're good for 10+ years of service. Your 2014 unit isnt even broken in
The only thing that can cause slop like that is the coupler, GM and Ford's Eaton based SCs all use a spring loaded coupler that feels sloppy like that quickly. The "normal" designation is not unique to LSA owners
Bearings sound horrible with the engine running and have a "dragging" feel when spinning the unit by hand. They do not give slop like that, doesnt matter how shot they are. Besides, they're good for 10+ years of service. Your 2014 unit isnt even broken in
The only thing that can cause slop like that is the coupler, GM and Ford's Eaton based SCs all use a spring loaded coupler that feels sloppy like that quickly. The "normal" designation is not unique to LSA owners
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Teching In
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From: Central Indiana
GM also released a bulletin explaining that:
- They would replace LSA superchargers on 2009-2013 cars with the 'marbles' rattle;
- The reason was the old spring coupler would cause wear which could contaminate the bearings, and;
- The new unit (used on all 2014MY cars) has a solid coupler which might cause the new noise I'm experiencing - but only on manual cars.
So, indirectly, my answer seems to be 'yes', the slop in my clip is normal.
