Along with Jim Seals, the Texas-born musician, whose real name was Darrell Crofts, was also known for soft rock tracks Diamond Girl and Get Closer.
His death was announced by his producer Louie Shelton on Thursday, and friends have remembered him as a "true music legend" who "helped create some of the most timeless songs ever written".
In a post on Facebook, US producer Shelton wrote: "Sad to hear our dear brother and partner in music has passed away today.
"Sending love and prayers to all his family and many fans. R.I.P. my brother… Dash Crofts."
The rocker was also remembered by US country singer Pauline Reese, who shared a series of photos with Crofts on Instagram and wrote: "Yesterday we lost a true music legend, Dash Crofts.
"I had the honour of meeting Dash through one of his closest friends, my keyboard player Mitch Connell.
"Even more special, he came with his wife Louise to watch me perform. That is something I will never forget.
"I feel truly blessed to have gotten to know him, even if only a little bit.
"As one half of Seals and Crofts, Dash helped create some of the most timeless songs ever written, including Summer Breeze, Diamond Girl, and Get Closer.
"His music has a way of bringing a sense of peace. What stood out most to me was not just the music, but who he was.
"He was kind, humble, and full of soul. Rest easy, Dash. Your music will live on forever.
"My deepest condolences to his family and close friends."
His musical partner James "Jimmy" Seals died in 2022 aged 80.
Seals and Crofts formed in the late 1960s, with the two men having known each other as teenagers, and were among a wave of soft rock groups that included Hall and Oates, America and Bread as well as England Dan and John Ford Coley.
They disbanded in 1980 but reunited in 1991 and then again in 2004 to release their final album Traces.
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