Has GM ever come up with a fix for this issue? I know about a year ago a TSB was out on this issue but it said no fix available at this time. It happens mostly on quick hard acceleration. Mine just did it today when I blipped the gas pedal and the trans did a downshift.
My SSR: '06 PB #21661 Born 8/29/05, GHL "Old School" True Duals, ADDCO bars, Eibach rear, Joe's Tune
It's the alternator slipping on the belt. The snap changes in engine rpm are too much for the inertia of the large capacity alternator.
The TSB is to change out to the alternator with the sprague clutch in it. It will free-wheel when the engine rpm does a snap change down and the alternator is still spinning at high rpm.
By the way, it is a 3:1 ratio from the crank. When youare turning 6,000 rpm, the alternator is turning 18,000. Physics will do the rest.......
Mike
__________________ Trust and Generosity are contagious.
My SSR: "Slingshot Yellow" 05 auto License plate "BIG V8"
fix for belt squeal
Quote:
Originally Posted by BetterMost
Has GM ever come up with a fix for this issue? I know about a year ago a TSB was out on this issue but it said no fix available at this time. It happens mostly on quick hard acceleration. Mine just did it today when I blipped the gas pedal and the trans did a downshift.
There is a special alternator pully available from GM with a one way clutch that will solve this problem. However to eliminate the cause, do a computer tune. Believe it or not the squeal is caused as a function of torque management when the tranny shifts the computer backs off the throttle and momentarily retards the spark the engine slows faster than the alternator because the alternator is overdriven by the pulleys (runs at about 15,000 rpm at 6,000 rpm engine speed) and it squeals the belt when the engine momentarily slows. Sounds like BS but this is the answer.
with Poppa. Without the custom tune in, the belt will make that noise. With the tune installed, no noise. Even with the gear change it dose not make the noise. HAMMER DOWN!!!!
My SSR: 19608 Silver BOD 12/20/04 Purchased 11/04/05 Auto/Predator
Gone after preditor tune
Quote:
Originally Posted by OC
with Poppa. Without the custom tune in, the belt will make that noise. With the tune installed, no noise. Even with the gear change it dose not make the noise. HAMMER DOWN!!!!
Also agree. Mine use to make noise only on full trottle from first to second. I was ready to send her in until I installed the Diablo tune.
Subject: ASI Resolution - Serpentine Belt Chirp and/or Squeak Noise During Hard Acceleration or Wide Open Throttle (WOT) While Upshifting or Downshifting (Replace Generator) #04-06-01-031A - (08/30/2005)
This bulletin is being revised to include repair, part and labor information. Please discard Advanced Service Information Bulletin 04-06-01-031 (Section 06 -- Engine/Propulsion System).
Condition
Some customers may comment on a chirp and/or squeak noise from the front of the vehicle during hard acceleration or WOT on upshifts or downshifts.
Cause
It is possible that the serpentine belt may momentarily slip on the crankshaft pulley during hard acceleration or WOT while upshifting or downshifting due to the inertia of other components on the serpentine drive belt system, causing a chirp noise.
Correction
Replace the Generator, P/N 15288861. Refer to Generator Replacement (SI Document ID# 1532884).
Parts Information
Part Number
Description
15288861
Generator
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation
Description
Labor Time
J4100
Generator Assembly - Replace
Use Current Published Labor Time
Dealer Action
Contact customers that were told they would be notified when a fix became available.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
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My SSR: '06 PB #21661 Born 8/29/05, GHL "Old School" True Duals, ADDCO bars, Eibach rear, Joe's Tune
Seems Logical
Jim,
I can't imagine that it would not be interchangeable. The only way to tell for sure is to get an '03 and an '06 side by side and do a quick swap. Only one belt tensioner and three bolts or so to do it.....
Mike
__________________ Trust and Generosity are contagious.
Mike in AZ: What I am thinking is that on any of the supercharged SSRs, regardless of model year, a sprague clutch would help take some of the load and wear off the already challenged belt and pulley system.
Mike in AZ or 2005SSR6speed: Can that alternator with the sprague clutch also be installed on a 2003/2004 (LM4 powertrain equipped) SSR?
Just chasing down an idea here . . .
Jim G
I know the regular alternator fit into my '99 Silverado (I bought one used off Ebay) I just had to get a longer belt as the factory unit was only 105A and has a smaller diameter body (mounting's the same).
my belt squeal went away after I changed the torque management via computer tune, now the only squeal I here on an upshift is the rear tires, and I can live with that.
Well,..I learned a lot from this thread for sure. I was going to squirt some belt dressing on the belt now im not. It would appear the slipping is needed with the old alternator setup to keep the belt from snapping. I will leave it be until I can get it in for service for the oil leak.
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with Poppa. Without the custom tune in, the belt will make that noise. With the tune installed, no noise. Even with the gear change it dose not make the noise. HAMMER DOWN!!!!
Linear Mode
