John Elway‘s longtime agent and friend, Jeff Sperbeck, is being remembered for being a great father … with his son posting a touching tribute to his late dad, who died in a tragic golf cart incident.

Jeff’s son, Jackson Sperbeck, just shared a bunch of photos of Jeff over the years on social media.

Jackson says … “Your footsteps gave me direction. I’ll walk the rest with purpose. I love you dad.”

TMZ broke the story … Jeff died last month after suffering a traumatic brain injury, falling off a golf cart Elway was driving inside of a swanky golf community in La Quinta, Calif.

Jeff’s death has been ruled an accident by the coroner, but police have been investigating the incident … though Sheriff Chad Bianco says there is no reason to believe any criminal activity was involved.

We’re told Elway, Sperbeck, their wives, and John’s son were on their way back from a post-Stagecoach party around 7 PM on April 26 … when Jeff fell off the back of the cart, hitting his head on the ground.

He was rushed to the hospital and put on life support … with doctors keeping him alive so they could harvest his organs for donation.

Elway mourned Jeff’s death publicly in the hours after his passing … writing in a statement, “There are no words to truly express the profound sadness I feel with the sudden loss of someone who has meant so much to me.”

Jeff’s family said he “was a wonderful father, husband, brother, son and friend to many” who “will be profoundly missed by all.”