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03-25-2011, 10:13 PM #1
- Join Date
- Mar 2011
HARD shift after driving for 30 minutes
I have a 99 GMC Suburban LS 4x4, auto trans. I just bought this truck and previuos owner had it sitting for 5 months. I have put 500 miles on the truck.
It shifts smooth as silk when running 20 minutes or less. If I run it longer, I get very HARD shift on 1st and a medium HARD shift on 2nd. Truck has 173k miles.
Trans fluid looks good and does not have a burned smell.
What steps should I take to resolve. Do the Trans coolers go bad and need to be replaced? Do I need to get a trans flush ? Do I ndeed a repair?
Any help would be apprecaited.
03-26-2011, 02:22 AM #2
- Join Date
- Feb 2011
- Locust Grove, Georgia, United States
your valves in the valve body are getting hot and sticking1999 GMC Serria
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55w 12000k Hids highs and lows with low and high relay
Viper Remote start
200 psi Train horns and onboard air
285 Courser M/ts
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