Van Gaal needs time - Ferguson
Ferguson stepped down from his role at Old Trafford in 2013 after nearly 27 years at the club, in which time he won 13 Premier League titles, two UEFA Champions League crowns and nine major domestic cups.
David Moyes was appointed his successor, but the former Everton boss failed to impress and was sacked four games before the end of 2013-14 as United finished seventh and missed out on European qualification.
Van Gaal's reign at Old Trafford has got off to an inconsistent start, featuring surprise defeats to Swansea City and Leicester City in the league, as well as a 4-0 hammering at third-tier Milton Keynes Dons in the League Cup.
The high-profile arrivals of Angel di Maria and Radamel Falcao have given United a boost, with the team claiming back-to-back wins over West Ham and Everton before the international break.
And Ferguson - who took three full seasons before delivering his first trophy - believes Van Gaal is doing an admirable job as the club look to recover from the disappointment of Moyes' brief tenure.
"He's not been getting the results that are expected but when I came to the club I didn't get the results I expected myself at the beginning," he told MUTV.
"What we needed then was Sir Bobby Charlton, Martin Edwards and the board to stick by me and we had a great spell after that. Once I got settled into the club, everything was fine. Louis is going through that same process and there's no doubt in my mind that he will sort it out."
Ferguson says the pair continue to have a good relationship, but that they are not in regular contact, despite the Scot's role as a director at Old Trafford.
"I've always got on well with Louis," he said. "The first occasion was when we played Barcelona in 1998 when we were in the group stages together. He was asking me how I dealt with the press and I said I've got a few interesting things about that!
"He had a different approach to the press at that time. My advice was don't read it. Don't get yourself upset about it. He has his own way. Watching his press conferences actually it's quite interesting. He's very, very honest in his press conferences, which is interesting.
"There's no ongoing dialogue. He comes into my office sometimes after the game, into the lounge, and we have a chat. But it's not a matter of picking up a phone or anything like that.
"He's a very capable person with a strong mentality. He's a strong leader. He knows where I am if he ever did need me but there has not been any need for him to phone me."