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Eating Transmission

yzav8r

By yzav8r
in Ask A GM Technician

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yzav8r New Member

yzav8r

Posted
Posted

Hi all,

 

I've got a 2001 Sierra 1500 4X4, originally with a 4.8, now a 6.0.

 

I've killed 4 transmissions. All 4 were used units, none with over 25000 miles. Two were left stock, one modified with a Vette & Sonnax Superhold servo, and the 4th with a full transgo HD-2 kit + Vette & Sonnax servos. All times the converter was swapped with different units and the cooler flushed. I monitor temps with a AeroTech scan gauge and have never seen a temperature over 160'F; nor have I ever read a code or had a MIL light. Failures occured with both a stock tune and two different tunes from Wait4Me, 3 failures were with the 4.8, this last one was behind the 6.0.

 

All failures occur while highway driving with a 'false neutral' whenever in D or 3; manual 2 and 1 work great.

 

I beat on the truck, I've always expected a sunshell or some other failure, but it's been my least abused point that fails.

 

 

 

I'm at a loss with this one; am I looking at a chassis electrical problem here? Thoughts? Things to track down?

 

I don't want to drop the money on a Finish Line trans if I'm just going to kill it again from some other problem.

 

 

 

Thanks,

 

Paul

silveradobobby Enthusiast

silveradobobby

Posted
Posted

I'm thinking you have a 4l60 if you drive it hard and its a 4x4 your going to be loose these trannys they are very weak to start with and do to low pressures for the 3-4 clutch pack its common problem your going to need to get a Built trans to handle what you give it. Sounds like your pushing it hard especaily with being a 4x4 u will eat those trans all day long. Servos and hd kits arent going to help you in the 3-4 clutches area you need a built trans now that u have the 6.0 behind it.

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