New the the forum here, Hope to get a few solid responses to calm my frustration.

I have a 98 s10 zr2 4x4..4l60e trans.
The last month it has been acting up..
I have about 4-5 hours on the web and forums in search of a solution. I have only ran acrossed 2 similar situations but no solutions as of yet.

My issue:
Initially noticed as a 100-200 rpm fluctuation from 45mph to 57mph
Does this constantly between these speeds
After the TC lock up is made (3rd and 4th gear)it slips back out and then right back in to lock up, (sometimes bouncing back and forth several times)when under light to medium load. It does this in 3rd or over drive. As soon as I hit 58 MPH in OD the converter stays locked in. The problem is, most roads I drive on are 45-55 MPH

I have new plugs, wires, cap, rotor, fuel filter.
I have checked the brake switch and swapped in a different tps/throttle body
Trans shop of course said that I need a new trans
Mech shop does not know what to do..No codes or engine lights

Anyone have an answer for this one?

 

98 S10, 4x4, 150k, same symptoms. One national tranny repair said rebuild, it's about to go, $1800. Took it to an independent shop, told it shifts so nicely in the other gears, better than most, leave it alone unless you get tired of it. A cusomer at Auto Zone said it's an internal valve, no harm, if I don't like it drive faster or slower. A 4th opinion said the TPS.
Not my daily driver, mainly use it to plow snow, so I'll leave it alone.
Sorry no solution, just a few suggestions.

 

Any update on this. I have the same issue. I had a TPS code, so I replaced the TPS. That did not fix the issue.

 

mine had the same issue, its the torque lock up sensor. under trans pan two bolts and two wires to hook up, put back together and add new fluid (might as well change your filter while you're there)