Low and High Temperature Non-Newtonian Behavior of Automatic Transmission Fluids General Motors Powertrain

Format:

Conference/Event

Author/Creator:

Sarkar, Reuben, author.

Conference Name:

Spring Fuels & Lubricants Meeting & Exhibition (2002-05-06 : Reno, Nevada, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2002

Summary:

Rheological properties of automatic transmission fluids (ATFs) are typically characterized by their kinematic (ASTM D 445) and Brookfield (ASTM D 2983) viscosities. However, ATFs contain polymeric viscosity modifiers, which often result in non-Newtonian fluid behavior as the polymers align and stretch under the shear stresses experienced in automatic transmissions. Therefore, the standard rheological tests, which are normally run under low shear stresses, may not adequately characterize an ATF's flow properties under the operating conditions of the automatic transmission. This study was designed to characterize the rheological properties of ATFs containing different amounts of viscosity modifiers, different base oil types and different levels of permanent shear stability under the shear and temperature conditions which exist in automatic transmissions. The results indicate that fluids with the same kinematic and Brookfield viscosities can have viscosities under typical transmission operating conditions that differ by as much as 40%

Notes:

Vendor supplied data

Publisher Number:

2002-01-1695

Access Restriction:

Restricted for use by site license