Can a service tech tell me the procedure for determining if the stock shocks are blown? The application is an 05 EC, SB, 4x4 Duramax Sierra. The stock shocks are failing to operate properly. If I park the truck and rock it side to side, when I let go it will continue to bounce a total of four times. If I push up and down on the rear shocks, it will bounce about three times. The fronts are very tough to push down. I would hate to have the dealer tell me that the shocks are within spec, thus the request to find out how the dealer will test them. Thanks.

I really can't comment on what your dealer will say but, I would suggest that you just purchase aftermarket shocks. Otherwise you'll get the same as what you have now and they aren't very good and don't last very long.

I agree with Hound. I replaced the factory shocks at less than 15000 miles and the rears were shot at that low mileage. Bilsteins took care of the rearend bounce the truck had and I prefer the firmer feel to the stock shocks.

Struts or Shock Absorbers On-Vehicle Testing

<TABLE width="100%" border=1><TBODY><TR><TH vAlign=bottom align=middle>Step
</TH><TH vAlign=bottom align=middle>Action
</TH><TH vAlign=bottom align=middle>Yes
</TH><TH vAlign=bottom align=middle>No
</TH></TR><TR><TD vAlign=center align=middle>1
</TD><TD vAlign=top align=left>Did you review the General Description and perform the necessary inspections?
</TD><TD vAlign=bottom align=middle>Go to Step 2 (http://service.gm.com/servlets/BlobShtml?ShtmlFile=824949&evc=sm&pubid=1058&cellId=59163&mspsdsubkey=4142#S02)
</TD><TD vAlign=bottom align=middle>Go to Symptoms - Suspension General Diagnosis (http://service.gm.com/servlets/CellHandler?CellId=62585&RefDoc=824949&evc=sm)
</TD></TR><TR><TD vAlign=center align=middle>2
</TD><TD vAlign=top align=left>Verify that the customer's concern is present.
Does the vehicle operate normally?
</TD><TD vAlign=bottom align=middle>System OK
</TD><TD vAlign=bottom align=middle>Go to Step 3 (http://service.gm.com/servlets/BlobShtml?ShtmlFile=824949&evc=sm&pubid=1058&cellId=59163&mspsdsubkey=4142#S03)
</TD></TR><TR><TD vAlign=center align=middle>3
</TD><TD>
Important

A light film of oil on the top portion of the shock reservoir is normal.

Inspect each strut or shock absorber for external fluid leakage.
Is a strut or shock absorber leaking?
</TD><TD vAlign=bottom align=middle>Go to Step 5 (http://service.gm.com/servlets/BlobShtml?ShtmlFile=824949&evc=sm&pubid=1058&cellId=59163&mspsdsubkey=4142#S05)
</TD><TD vAlign=bottom align=middle>Go to Step 4 (http://service.gm.com/servlets/BlobShtml?ShtmlFile=824949&evc=sm&pubid=1058&cellId=59163&mspsdsubkey=4142#S04)
</TD></TR><TR><TD vAlign=center align=middle>4
</TD><TD><LI type=1>Use your hands in order to lift up and push down each corner of the vehicle 3 times. <LI type=1>Remove your hands from the vehicle.
Locate a shock or strut that exceeds 2 cycles.Did you locate a shock or strut that exceeds 2 cycles?
</TD><TD vAlign=bottom align=middle>Go to Step 5 (http://service.gm.com/servlets/BlobShtml?ShtmlFile=824949&evc=sm&pubid=1058&cellId=59163&mspsdsubkey=4142#S05)
</TD><TD vAlign=bottom align=middle>Go to Step 6 (http://service.gm.com/servlets/BlobShtml?ShtmlFile=824949&evc=sm&pubid=1058&cellId=59163&mspsdsubkey=4142#S06)
</TD></TR><TR><TD vAlign=center align=middle>5
</TD><TD vAlign=top align=left>
Important

Inspect the vehicle trim height in order to correct any possible causes of shock/strut failures. Refer to Trim Height Inspection Procedure (http://service.gm.com/servlets/CellHandler?CellId=59083&RefDoc=824949&evc=sm) .

Replace the strut or shock absorber. Refer to Shock Absorber Replacement (http://service.gm.com/servlets/CellHandler?CellId=47661&RefDoc=824949&evc=sm) in Front Suspension or Shock Absorber Replacement (http://service.gm.com/servlets/CellHandler?CellId=56035&RefDoc=824949&evc=sm) in Rear Suspension.
Did you complete the repair?
</TD><TD vAlign=bottom align=middle>Go to Step 6 (http://service.gm.com/servlets/BlobShtml?ShtmlFile=824949&evc=sm&pubid=1058&cellId=59163&mspsdsubkey=4142#S06)
</TD><TD vAlign=bottom align=middle>--
</TD></TR><TR><TD vAlign=center align=middle>6
</TD><TD vAlign=top align=left>Operate the vehicle in order to verify the repair.
Did you correct the condition?
</TD><TD vAlign=bottom align=middle>System OK
</TD><TD vAlign=bottom align=middle>Go to Step 3 (http://service.gm.com/servlets/BlobShtml?ShtmlFile=824949&evc=sm&pubid=1058&cellId=59163&mspsdsubkey=4142#S03)
</TD></TR></TBODY></TABLE>



A cycle is up, down then stop at center.