ANOTHER broke down Chevy Silverado

[chad austin]

Last night I was coming home from the gym and I noticed my tranny slipping a little, a block or two from home. I figured the fluid may be a little low. Well I went out this morning and started the truck and let it run for about 15 minutes and then checked the fluid and it read as normal, another 5 minutes go by and I checked it again and it barley registered on the dipstick (I assume it wasn't warm enough the first time).

So I put a quart of ATF in and put the truck in reverse - it seemed fine, put it in drive - seems fine. Shut the truck off for a minute and start it back up and nothing.

8 hours later I go out and start the truck and back up and down the driveway numerous times and it seems fine again. Anybody have an idea what this could be?

Could this be a torque converter on its way out?

[Macgyver55]

What year is it, how many miles, and when is the last time it has had a fluid and filter change?

In any case, its unlikely the problem is with the converter.

[chad austin]

I suppose that would help.

1994 Chevrolet Silverado 2500

236,000 miles and the last time it has had the fluid and filter was about 36,000 ago

[mnviking28]

When you say "start it back up and nothing", I am assuming that you meant that it wouldn't move? Or that it didn't act differently than normal or ...?? Have you ever replaced the tranny before?

[chad austin]

When you say "start it back up and nothing", I am assuming that you meant that it wouldn't move? Or that it didn't act differently than normal or ...?? Have you ever replaced the tranny before?

Started it back up and the truck wouldn't move in any gear. I have only had the truck since 200,000 so I can't say if it has been replaced or not. I have not done anything with the tranny except the fluid change when I bought it and checking the fluid level once in a while.

[chad austin]

is there anything electrical (relays) or anything that could be the issue?

[Macgyver55]

There are at least 3 solenoid controls that are accessible in the pan. There is also a "pass through" connector on the case where all the wiring goes into the case that I have see contaminated with fluid. That said, transmission diagnostics are admittedly a weak point for me, so I would recommend having a shop check it out, or wait and see if Jer or 4 wanderingeyes have any input.

[Jeremy airjer W]

That said, transmission diagnostics are admittedly a weak point for me, so I would recommend having a shop check it out, or wait and see if Jer or 4 wanderingeyes have any input.

You know I am NOT a transmission guru!

[Scott K]

If it is intermittently not engaging, it is more then likely not a electrical concern, since the only solenoid that would make a difference would be the pressure control solenoid, and it defaults to max pressure, so if it went bad, the trans would shift harder, not softer or at all. They design it that way so a bad solenoid, or open wire wont wreck the trans by running low pressure. It could very well be a stuck solenoid, but if it isnt trying to engage at all, then I would have to say it is tear down time. At minimum, remove the transmission pan, and look for excessive material in the pan. My guess though would be a bad seal that is bypassing fluid, and the pressure drops, and it wont engage.

I guess, I recommend removing the pan, and inspect from there. More then likely it will be tranny shop time though.

[chad austin]

That's what I was afraid of. The transmission has shifted hard from the day I bought it, the previous owner said he had a transmission shop install a different valve body to make the shifts "harder" for pulling his camper. When I say that it shifted hard, I mean when it did shift it was right there. There is/was no lull in-between gears.

Do you think it would be worth it to drop the pan and install a new filter and fluid if I don't see excess material in the pan or...?

Thanks guys for the replies, I can hold my own when it comes to auto repairs but transmissions, not so much.

[Scott K]

I would pull the pan, a plugged filter would have to be severely plugged in order to cause it not to shift, but it can cause it to cause damage. If the fluid is that bad, more then likely new fluid wont fix anything, its more of a prevention then a fix. But atleast if you pull the pan, and you see all kinds of chuncks, or clutch material, you know, you will more then likely be better off finding a used tranny somewhere and just replace it.

[chad austin]

Thanks again, I'll throw it on the lift this weekend and see what I can see. In the mean time I'll probably track down a used transmission.