“If it ain’t broke, don’t fix it” is an expression that was popularized by American businessman Bert Lance (1931-2013) in December 1976, referring to the machine of the federal government. It’s often said that this is an old Texas saying, but the exact origins are unknown. “If it ain’t broke, we can’t fix it” or “We can’t fix it if it ain’t broke” appeared frequently in the context of auto repair.
   
“If it Ain’t Broke, Don’t Fix It” is the title of an article in the Aerospace Accident and Maintenance Review in September 1962.
   
[The 1962 citation was found by Stephen Goranson and posted on the American Dialect Society listserv.]
 
       
Google Books
September 1962, Aerospace Accident and Maintenance Review, pg. 8:
If it Ain’t Broke, Don’t Fix It 
   
Newspapers.com
1 August 1964, Tucson (AZ) Daily Citizen, comics page:
BEETLE BAILEY by Mort Walker
AUTO REPAIR MAN TO ARMY SERGEANT (inspecting jeep): WELL, I CAN’T FIX IT IF IT’S NOT BROKEN!
 
1 December 1973, Florence (SC) Morning News, “Auto Repair Service” classified ad, pg. 10A, col. 6:
IF IT AIN’T BROKE—
WE CAN’T FIX IT
Foreign or American
Hill’s Pine Forest Shell
160 Pamplico Highway - 669-2791
 
22 September 1974, Coshocton (OH) Tribune, comics page:
GASOLINE ALLEY by Bill Perry
COMIC PANEL ONE:
CUSTOMER: Sarge, if you can’t do any better, you ought to remove that sign!
AUTO MECHANIC: What sign?
 
COMIC PANEL TWO:
[Sign: IF WE CAN’T FIX IT—IT AIN’T BROKE]
AUTO MECHANIC: Oh that? Hack put that up.
 
COMIC PANEL THREE:
CUSTOMER: I don’t care who put it up! Fix my car or take it down!
   
18 May 1976, Atlanta (GA) Constitution, “Williams Says Jobs Are Not Government’s Role” by Sam Hopkins, pg. 2-C, col. 2:
He (First National Bank President Thomas R. Williams—ed.) added, “There is an old Cajun saying that applies here, ‘If it ain’t broke, don’t fix it.’”
 
The Yale Book of Quotations
Edited by Fred Shapiro
New Haven, CT: Yale University Press
2006    
Pg. 441:
Bert Lance
U.S. politician, 1931—
If it ain’t broke, don’t fix it.
Quoted in Wash. Post, 23 Dec. 1976. Lance popularized this expression, but the Wall Street Journal, 4 Oct. 1976, printed the following: “‘If it ain’t broke, let’s don’t fix it,’ says Mr. Davant, quoting an old Swedish saying from his home state of Minnesota.
 
26 December 1976, Sunday Sun (Lowell, Mass.), pg. 39?, col. 1:
The machinery of the government here is a little creaky, but not all that bad. As Bert Lance told the editors of the Washington Post the other day, nobody’s going to tear the machine apart. “It it’s not broke, why fix it?” he said.
 
Google Books
Texas Music
by Rick Koster
New York: St. Martin’s Press
2000
Pg. 126:
And though the old Texas adage warns that if it ain’t broke, don’t fix it, in Pantera’s case, they’d probably taken their brand of crazoid rock as far as it could go.
   
Texas State Senator Jeff Wentworth
From the Office of State Senator Jeff Wentworth
March 26, 2004
Senate select committee examining injured workers’ problems
 
There’s an old saying in Texas, “If it ain’t broke, don’t fix it.” 
   
Brownfield News (Des Plaines, IL)
April 4, 2006
If it Ain’t Broke, Don’t Fix it
By Jeff Hubbard
Here in Texas, we have a saying: “If it ain’t broke, don’t fix it.”
 
Google Books
Change or Die: How to Transform Your Organization from the Inside Out
by M. David Dealy
Westport, CT: Praeger/Greenwood
2005
Pg. 27:
“We in Texas have a saying that if it ain’t broke, don’t fix it!” she said. 
 
Texas Governor Rick Perry
Statement of Tom Pauken
August 21, 2006
Thank you, Governor Perry. It is an honor to have the opportunity to work on an issue that has been a concern of mine and countless other Texas taxpayers for many years - the need for appraisal reform in Texas.

There is an old Texas saying that I often use, “If it ain’t broke, don’t fix it.”