The pair will fight for Wood's WBA Pan African middleweight title and the vacant IBF Pan Pacific belt at Sydney's Hordern Pavilion.
Both Wood (12-3-1, 8 KOs) and former WBA and IBF world champion Geale (29-2, 15 KOs) made it abundantly clear they have no respect for each other.
Geale needed three attempts to make the weight - but the fireworks started after the two fighters posed for the traditional post weigh-in face off.
Geale shoved Wood away after the latter pushed his head into the former world champion and fired off some words at him.
"He was talking crap and I expected all that," said Geale, who is fighting for the first time since losing the IBF title last August.
"He went along the lines of telling me that he reckons it's his area and he's going to do whatever he wants to me.
"I only reacted when he head-butted me. It was a sneaky shot.
"He was was probably trying to cut me like I know he probably will (on Wednesday) as well.
"He's going to try and frustrate me and upset me and head-butt me and do all that stuff and I'm expecting that."
Asked what he said to Geale, Wood said: "I just let him know that I've been shown nothing but disrespect from day dot.
"His record and who he is ... it's out the window because this is my house and this is my area, he's coming to the hood.
"He must remember that, so it's going to be a streetfight.
"Etiquette is out the door with me. It's going to be war, so expect the unexpected."
Geale will rely on his speed and skill to overcome the unconventional and awkward Wood.
A victory would keep Geale in line for fights later this year against WBA champion Gennady Golovkin and IBF king Felix Sturm.
Geale initially weighed in at 72.65kgs, fractionally over the limit of 72.57, while Wood scaled 72.15.
Geale scaled 72.60 after removing his underpants and came in at 72.55 around half an hour later after going for a walk.
NSW and Cronulla Sharks captain Paul Gallen wasn't concerned at weighing in just over 10 kilos lighter than Queenslander Herman Ene Purcell for his heavyweight professional debut.
"The (amateur) fight I had against Hika Elliot, he was about 15 kilos heavier than me, " said Gallen, who won that bout.