i have a 1987 toyota pickup 4 wheel drive that i just put a new ifs in and new hubs?

[James P]

when you lock into 4 wheel drive it wanders real bad back and forth across the road i took it to the local tire shop here and they told me it was a inch and a half out of tow and that is why it is wandering like that is this possible? you can just lock in the drivers side and it is fine but when you lock both of them in is when it does this