Transmission Fluid X Hydraulic Fluid

[nyko46]

As hydraulic fluid are designed to run hydraulic units in industrial equipments,
how will this fluid work in a automatic transmission?
The thickness between transmission fluid and hydraulic fluid are basicaly the same and the concept of both units, transmission and hydraulic unit are the same.The porpouse of both fluids are generate a hydraulic force using a pumping system.Do you agree or not?
If so, do you think that hydraulic fluid can replace transmission fluid?
I would like to read your opinion.
A happy 2007 to everyone.
Nyck

[Chas H]

ATF is formulated for auto trans. Hydraulic oil is formulated for hydraulic applications. Why in the world would you want to exchange them?
To answer your question. I don't think one can replace the other.

[sokoloff]

Not for very long anyway.

Len

[Kestas]

Transmission fluid needs to meets certain criteria that plain hydraulic fluid cannot - mainly it needs to allow "grip" of the friction elements.

There may be other characteristics different between the two fluids:
- temperature operating range
- detergency
- dirpersants
- antifoaming
- shear resistance
- viscosity improvers

Transmission fluid is highly engineered. Even among the hydraulic fluids there are different grades depending on the requirements of the end user. There's no way I would put in unapproved hydraulic fluid in my transmission.