If it starts in 3rd, I don't think there is any external adjustment to fix that. Does it upshift to 4th? Can you move the shifter to low to force it down?

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1985 380SE Blue/Blue - 230,000 miles
2012 Subaru Forester 5-speed
2005 Toyota Sienna
2004 Chrysler Sebring convertible
1999 Toyota Tacoma