overheating transmission

1999 GMC SIERRA
226,000 MILES • V8 • 4WD • AUTOMATIC
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RINKRATT14
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I have a 99 GMC Sierra 2500 4 wheel drive with a 6.0L engine,an a 4L80E tranny. Today the transmission temperature gauge indicated it was overheating. all fluids are good the cooler seems to be clear and there are no leaks. What is the normal transmission operating temperature of this vehicle, and could a bad transmission filter cause overheating? what other things could be the cause?
Feb 13, 2011 at 1:22 AM
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MHPAUTOS
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I would get the transmission checked ASAP, the cooler will have to be flow tested you can't tell if it is part blocked any other way, a blocked filter may cause some problems, but slippage is the main cause, with that said, it may even be a faulty temp sender, a scan may show that up, a trans tech is qualified to do all these tests and more, do not delay, if there is a problem it may cost a lot more if you wait.

Mark (mhpautos)
Feb 13, 2011 at 2:36 AM