After running my 99 Jimmy for an hour, it jumps from first to second gear hard? Any answers why?
sounds like a high millage on vehicle do you do any towing /4wheeling with it i would pull trans cover plate to do a fluid and filter change and check it for either metal or plastic parts or even metal shavings if non of these are there then i would check to see if it has a shift solenoid look for a small group of wire usually leading to driver side of trans on my high millage trucks i install a trans cooler which helps cool down a over worked trans
Had the same problem on a 4L60 tranny, replaced the solenoid pack and the problem went away.
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