Help! PO put engine oil in the ATF!

So my mechanic called, and a new twist has occurred in the Cutlass saga. Apparently the PO or the PO's mechanic put up to a quart of 10W30 in the ATF. Should I even try flushing the trans?

What was the issue he was checking out? If it's been working ok I'd flush it and keep driving.

Not a big deal. Drain it and refill. If it were me I'd probably just drive it.

How did he know that?

Sweet cover up story he came up with.

In reply to RossD:

What I was going to say. No way in hell you can look at trans fluid and know theres a quart of 10w30 in there.

In reply to chiodos:

Plus Juan

I think you need a new mechanic.

Ask what brand of 10w30 is in the trans, I bet your "mechanic" knows

Seen engine oil used in some race automatic transmissions before since it doesn't compress like atf can....

I'm pretty sure all fluids are incompressible (or close enough to it)

I'm really curious about why and how your mechanic was checking your transmission fluid.

iadr wrote: Trying to think of other combo's.

A long time ago, I was guilty of putting diesel in the hydraulic tank of a forklift. Made the cylinder seals leak more than just a bit

Yeah I think there's a good chance this guy did it by accident and is trying to cover it up. Nobody's perfect...just drain and refill.

Back in the days of F type fluid it was common to add 1qt of engine oil to the auto trans if you were racing.

I once put de-icer concentrate (that was supposed to be diluted 100:1 or something crazy like that) in my windshield washer reservoir. Thankfully, I realized it, drained it, and flushed it several times before it could cause any damage.

In my defense, it was right next to the "winter washer fluid" on the shelf and was the same color (orange). Only after dumping the gallon in did I read the label

That old car could use a drain, filter replacement and new fluid anyways. Dont have anyone flush it unless you really want a new trans.

Edit thats flush with a oil change place power flusher, big no no. But theres a way to flush it yourself thats not harmful but thats a story for another time.

Brake fluid in the power steering reservoir does bad things.

iadr wrote:

Ranger50 wrote: Seen engine oil used in some race automatic transmissions before since it doesn't compress like atf can....

Trying to think of other combo's.

I put oil in power steering resevoir one time. PS was right next to oil cap. They never came back to say anything messed up. So I assume it was okay. That or it messed up and took it somewhere else.

Thanks for the advice everyone, I'll just drain and refill the ATF myself. Who knows what the PO was up to. All I know is that when my car came off the trailer, my mechanic checked the ATF and said 'It feels like someone put oil in the ATF.' When I asked how much, he said 'Most likely it's only a quart.' I guess that in a year or two, it will be TH-350 time.

N Sperlo wrote: I'm really curious about why and how your mechanic was checking your transmission fluid.

Whelp, it was fresh off the trailer, and he was giving it the once over. He pulls the trans dipstick, wipes it on his fingers, sniffs it, and says that someone put motor oil in the ATF.

G_Body_Man wrote: I guess that in a year or two, it will be TH-350 time.

Or consider the 700r4. Its basically a th350 with an overdrive. Should be pretty easy. I think they are a little longer, so you would need a shorter driveshaft and a different crossmember, but that stuff should be easy to find. Then with the OD you can swap to some deeper gears, which I think you talked about on here before, correct?

K-Y Jelly makes poor gear lube.

In reply to SVreX:

Do you prefer Vaseline or spit when someone is rowing the gated shifter?

In reply to SVreX:

The warming jelly helps with a cold start.

G_Body_Man wrote:

N Sperlo wrote: I'm really curious about why and how your mechanic was checking your transmission fluid.

Whelp, it was fresh off the trailer, and he was giving it the once over. He pulls the trans dipstick, wipes it on his fingers, sniffs it, and says that someone put motor oil in the ATF.

Isn't atf pretty much just 5 or 10 weight oil?