99 sonoma torq converter lock up /O.D. ?

[basszzilla]

I have a 1999 sonoma highrider 4x4. torq converter can't decide if it wants to stay locked up or not. when I first get on the hiway it works fine. after about 5 miles or so it will just unlock, it may go another 5 or 10 miles before it locks up again. and then just goes back and forth like that.I can't really figure any type of consistancy. sometimes it seems to work in reverse(i.e. lock up on inclines and unlocks on declines) any help would be great.

[Schrade]

Sounds like a fluid supply problem - turns, inclines, etc.... What's the level look like?

[basszzilla]

fresh tranny service, done @ every 20k, fluid looks and smells good (well it doesn't really smell good, but smells unburned).

[rlith]

It's supposed to work that way. When there is more load on the engine it will lock up to give direct power to the transmission. On declines it will unlock because that power isn't required (unless you stomp on the gas in which case it will lock up again)...Do a search on the way torque converters work and you will see what I mean.