One of the guys from work comes in today and tells me that he wasn't paying attention this weekend and accidentally put tranny fluid instead of oil... He drove it 200 miles last night.. So he asks me, "what's the worst that can happen?"

So, what exactly would happen if he didn't change it....

 

The worst thing that will happen is that hie engine will get cleaned out inside. It's a good thing actually, no harm will occur, I've been doing it for .... several decades now as a maintenance procedure.

 

Really???

 

Umm ok i heard that adding 1 quart for about 50K before every oil change was normal a while back.

But this is pure tranny fluid. Doesnt it do anything to all the gaskets ect... in the motor?

All i know is it cant be perfectly good.

 

Stroked,

While the transmission oil doesn't necessarily have the same lubrication properties as oil formulated for the engine, one quart of trans oil in the sump with four quarts of good engine oil isn't a major problem. At least he didn't add antifreeze.

I would drain it as soon as possible and install a new filter and good engine oil. He may be surprised at how dirty the drained oil is.

It's a good way to use up those old stocks of Type 'F' trans oil since it isn't good for much more than starting fires any more.