shift flares?

[BerniniCaCO3]

Hi!

I think I'd noticed something like this in months past, but it seems to be a bit more frequent.

I have a 1990 GM wagon with 123,000 miles on it. When I bought it, at 109,000, the seller had rebuild the transmission at 103,000.

There's a shift flare usually coasting up a hill between 20 and 40mph, when I even very gently tap the gas, as if it wants to downshift, but then decides not to.
If I hit the gas harder, it does downshift, and hard. But if I try to maintain speed in the present gear, it will hesitate-- again, as if it's thinking about downshifting and then doesn't and goes back to the present gear.

But more recently, I have trouble --possibly on cold starts, as it was both this morning and again leaving work-- moving in first gear? Now, once I'm in gear, I should be IN GEAR, so unlike say my 2nd-3rd shift (I'm guessing), there's no question about hovering in between gears. It's in first. End of story.
So why, as I drove up a slight slope and stopped at a stop sign to make a left turn, when I went to make that turn, did I rev to 3000rpm doing nothing for as long as 2 seconds before I got any torque at the rear wheels?

I checked when I got home: transmission fluid is clean as new, and if anything possibly overfull by the smallest margin (1/8" past the hatches). TV cable hooked up at the throttle.
fwiw, I had a coworker adjust the tension a little higher to move the shift points up. Maybe this pretension is why I'm getting that "going uphill @20-40mph" flare, and I need to loosen it?
I'm not sure it as readily explains no torque transfer in 1st gear pulling away from a stop sign?

[BerniniCaCO3]

The weather has been consistently colder, if this is just life with an AOD after a cold start in the winter, and I need to live with it?

[gadget73]

sounds like either the pump is weak, or its sucking air. what you're getting is exactly the symptoms of low fluid level, but it can also be caused if the gasket around the filter is missing. This doesn't sound like one of the AOD quirks.

[Southern_Pride]

Did you check it with the car running? If so i'd check the filter.

[BerniniCaCO3]

You think that maybe a bit of the gasket has come loose and is bypassing (and losing pressure there)?
How much fluid will I lose when I drop the filter? (so I can buy that much, + a quart).
I will recheck the level again tomorrow, to be sure; but I'm 95% sure the fluid level is not low. I'd heard of that, though.

If it is the pump:
(a) where do I get one. Just checked NAPA and rockauto; napa has zilch, rockauto just has pump seals... but not a pump.
(b) can I install it myself w/o special service tools?

[jaywish]

Any very small bubbles in the fluid when the engine is running?

[gadget73]

replacing the pump requires removing the trans and pulling the torque converter. The pump lives underneath. Dont know if it requires special tools, but its really not something you want to do unless required. Typically you'd confirm the pump is bad with some pressure tests and such as outlined in the service manual. You'd also want to verify the TV pressure is good. A factory service manual has the specifics on all of that.

[jpc]

Mine made a funny upshift this morning. It let go of 2nd but didn't grab ahold of 3rd for a few seconds before it did. First time it's done that. The fluid level is correct. I'm not worried, this morning was frigid.

[ford man]

Yeah that sounds like the filter or related filter gasket to me too. Make sure you tighten the filter bolts to 90-100 INCH pounds. One of my bolts was stripped out and it would do funny things like that when I first got my car. Had to drill and tap one bolt hole to a bigger size.

You could throw a couple magnets in your pan while your at it for fun if you plan on keeping your car.

[BerniniCaCO3]

sounds good gadget, I'll peruse the manual and do some solid diagnostics rather than guessing.

Yeah, if I can duplicate the problem on another frigid morning, I have been informed that I want to see if it does it in reverse too. If so, clogged filter, or somehow bypassing gasket.
It hasn't happened since.

Hey gadget, just to keep in the back of the mind, what was that odd trans problem you had that killed your fuel economy? It may have been someone else; it was in a fuel econ thread a little while ago, maybe a month or three.
I'm on track for 11mpg this tank....

When is torque lockup supposed to enable, and supposed to disable, to confirm that that's happening also? Other than bad fuel economy, and being unable to see a change in the tach past overdrive, I have no reason to fear this. But it'll be good to know, how to know.

[gadget73]

don't have any real trans problems with mine, at least none that mess with my fuel economy.

Converter is fully locked in 3 and 4. Theres no lockup to speak of like you would see with almost any other transmission. The trans is really more of a pair of 2 speed transmissions than a 4 speed. 1 and 2 drive off the converter turbine like you'd expect, 3 and 4 are direct drive off the converter shell via a different input shaft. The only way for it to not lock up is to use a special non-stock converter, or to have that second input shaft snap. If that happened, you'd have no third and fourth gear.

[Southern_Pride]

You need a slide hammer to get the old pump out.

[BerniniCaCO3]

hmm, wonder if I misinterpreted, and I could have dragging brakes?
Even providing winter fuel and a short commute, my last tank had VERY poor fuel economy. I've come to terms with 15mpg wintertime, but even so, my last tank was just 11mpg. I haven't seen it that bad since my thermostat failed open!
If they were sticking, it would ALSO explain a car that too some rpms to get moving in drive.

I'd sorta assume I'd know if the brakes were not releasing 100%, but maybe it isn't always so obvious as a car that shakes on the freeway?
Check for abnormal brake wear (it's only been 15k since I did front pads), and check for blue spots on the rotors? Maybe see if someone has an infrared thermometer, and check the temperature after a drive?

[gadget73]

walk around the car and put your hands near the wheels after a drive. If one brake was dragging, that wheel will be noticeably hotter than the others.

[BerniniCaCO3]

Alright, I have a new theory now!

I replaced my transmission --for fun, and performance mods; old one is still good and I'm keeping it in reserve-- and adjusted the tv cable to spec.
What I learned was that a supposedly experienced friend, aiming to tighten the cable, had instead gone the wrong way and made it much too loose. I'm talking like a half an inch of travel before the tv cable starts to be pulled.

This means low line pressure.

I was working on the premise of a tight tv cable, so I was assuming that the car was trying to downshift going up a hill, when really all it was doing was slipping in what was probably 3rd gear, when there was load, going up a hill.
If I hit the gas approaching a hill, hard, it seemed to work, because THEN I pulled on the tv cable, kicked down a gear, line pressure went up, and it didn't slip in 2nd gear.
Downshifts/kick downs were firmer, because now it was well and truly at WOT before it would kick down, so when it kick down the engine had plenty of power and it would kick down with a satisfying punch.
Now it kick downs sooner, and more sensibly.

I simply completely failed to recognize and misinterpreted what was going on; this was a simple loose tv cable adjustment!