My 96 S10 has an occasional P1870 after HWY use when its hot. Researching this brings up a lot of reference of the TC slipping due to valve body wear. It seems a lot of people rebuild the trannie before ever trying to fix the valve body. A couple of companies make a kit to do this repair:
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Can the valve body be taken off a S10 with the trannie still in the truck by dropping the pan? Does it take any special tools to get the valve body off?. Is a driveway valve body repair/swap feasible?Bob