Paul Walker has been gone for over three years now, but his Fast and the Furious family certainly hasn't forgotten him.

With the franchise's eighth film, "The Fate of the Furious" (also known as "Fast 8"), in post-production, Walker's absence has understandably been very much on the mind of his long-time co-stars. Vin Diesel made no secret of the fact when he posted a touching message to his late friend on Instagram Wednesday. The action star reflected on the latest installment's "arduous road to production" and "the challenging task of filming" it.

Difficult as it has been, Walker has evidently been a motivating force. "You Pablo have given me strength... purpose and resolve," Diesel wrote to Walker.

Diesel also shared his hope that the film will be one Walker would be proud of and reminded fans, "Family above everything."

Diesel and Walker starred together in four Fast and the Furious movies over the span of a decade, and were in the process of filming a fifth (the franchise's seventh) when Walker died in a car accident on Nov. 30, 2013. "The Fate of the Furious" is the first in the series that Diesel has filmed entirely without Walker, so it's no wonder he still misses him.

"The Fate of the Furious" hits theaters on April 14.

[via: Vin Diesel/Instagram]