The actor, who was known to millions for his role as slow-witted Trigger in the much-loved BBC sitcom, died last month aged 69.
He had been suffering from pancreatic cancer.
His daughter, actress Emily Lloyd, led the service in central London, which also featured a pink hearse.
Co-stars John Challis, who played car-dealer Boycie, and Sue Holderness, his on-screen wife Marlene, were in attendance alongside Paul Barber who played Denzil and Patrick Murray who played Mickey Pearce.
Nigel Havers, Stephen Rea, Miranda Richardson, Alison Steadman, Kathy Burke and Joely Richardson were also amongst the other stars who attended the service at St Paul's, Covent Garden.
In a career that spanned 40 years, Mr Lloyd Pack was the only actor, aside from Sir David and Lyndhurst, to have appeared in both the first episode, in 1981, and last of the long-running sitcom.
He went on to attract a further host of fans by playing another dim-witted character, farmer Owen Newitt in The Vicar Of Dibley.
He had also appeared in films such as Harry Potter and the Goblet of Fire and Tinker Tailor Soldier Spy, and numerous other TV programmes.
More recently he had appeared the Shakespearean Globe Theatre alongside Mark Rylance and Stephen Fry in productions of Richard III and Twelfth Night.
Politically active, he was a committed socialist and campaigned for nuclear disarmament and left-wing causes.
After his death, Sir David lead the tributes to the actor, saying he was a "very quiet, kind actor who was a pleasure to work with".
He was married twice and, as well as his daughter, leaves three sons Spencer, Hartley and Louis.