Ok, I'm in the process of searching this one, but maybe somebody can help me diagnose a friends '96 Impala SS. The trans is the 4L60E I think. It has been 'cutting in and out' per his description. Car has 70k, stock engine, and has been running Hypertech calibration.

We ran the car at idle for about 10 minutes, cycled the gears, and checked the fluid. There is a noise kind of like low power steering fluid all the time that changes when you shift, even not moving. Fluid 1 inch too high, but trans not really hot after only idling. Fluid is pink and not burned.

He pulled out of the garage, shifted to reverse, and all gears totally stopped working. Not just slipping; nothing. We shut the engine off for a few minutes, and it recovered again. Have not driven yet.

The fact that the problem recovers by shutting the engine off makes me wonder if this is something other than just smoked clutches. Could high fluid cause trouble like this? Plugged filter? Failing pump? Insight would be appreciated.

 

That symptom would indicate two possibilities,
1- the filter is becoming clogged with debris "bad trans"
2- Its not full of fluid " Are you checking it warm with the car running?"

 

Yes, warm as 10 min idle would get it, which was not very. Don't dare drive it past the driveway anymore.

I don't expect an easy fix, but am interested to understand what kind of internal malfunction could explain the symptoms.

It does seem like the pump is intermittent - we tried it again, and noticed the noise is gone when the trans works. Is there any kind of fluid control in the pump circuit that affects all gears? The car sits for weeks, too. Could air get into the system somewhere, causing the fluid to appear high too? He hasn't had it serviced recently or added any fluid, so an inch high seems weird unless the dealer overfilled a long time ago.

We'll check the filter for fun I guess. But if we find it clogged, whatever clogged it will no doubt need to be reinstalled where it belongs. You can do that, right?

I've already showed him your stuff, BTW.

Thanks.

 

I am betting he is likely going to need a transmission and you will probably say the same once you pull the pan.
Frank