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U.S. Department of Energy
Office of Scientific and Technical Information

Hydraulic automatic transmission fluid with superior friction performance

Patent ·
OSTI ID:6138633
The friction performance of a lubricating oil composition that has been compounded to serve as a functional fluid that is particularly useful in mechanical and hydraulic units containing wet clutches, for example an automotive automatic transmission, is greatly improved by the incorporation of a combination of a friction modifier of the type comprising a straight chain alkenyl or alkyl C4 to C10 dicarboxylic acid or the reaction product of an aldehyde/tris hydroxymethyl aminomethane adduct and a long chain dicarboxylic acid anhydride such as an alpha-olefin succinic anhydride; with an overbased detergent salt such as an alkali metal salt or alkaline earth metal salt of a hydrocarbyl sulfonic acid, an alkyl phenol or a sulfurized alkyl phenol, in certain proportions.
Assignee:
Exxon Research And Engineering Co
Patent Number(s):
US 4253977
OSTI ID:
6138633
Country of Publication:
United States
Language:
English