Lucy-Jo Hudson, Halsall's wife of five years, revealed that the couple have been grieving for their friend and former co-star, who died in November aged 71.
"Losing Bill has affected us both but it has hit Al especially hard," she told the Daily Star. "In his early days at Corrie he was like a surrogate dad to Al and guided him.
"He taught him how to be professional and shared his words of wisdom. He will always be a legend and Al will never forget what he's done for him."
The Wild at Heart actress continued: "We're still in touch with Bill's wife Alma. She knows what a close bond they had so she gave Al Bill's watch, which he never takes off."
Hudson further commented that Tarmey would have been "so proud" of Halsall's recent National Television Award nomination for his portrayal of battered husband Tyrone Dobbs.
"I know Bill would be so proud of Al's NTA nomination. If he wins, he would be winning it for him," she said before adding, "Bill was such an incredible man and we have so much love and respect for him".
Heaping praise on Halsall's performances, Hudson said: "Finally, after 15 years at Corrie, he's got a bit of recognition and I'm so proud of him but he thoroughly deserves it. I've been in awe of his performances. Some scenes have had me in tears.
"He never watches himself on telly so I do a series link and watch when he's filming at the studio. I'd love to sit him down and just say, 'Please watch this because this is how good you are', but he just thinks of it as his job and takes it all with a pinch of salt.
"He's had brilliant storylines but domestic violence, especially when it happens to a man, is a sensitive subject and Al's not gone into it lightly."