A method of monitoring longitudinal stability for a lift vehicle using a longitudinal stability system, the lift vehicle including a vehicle chassis supported on front and rear wheels respectively coupled with front axle and a rear axle, and a boom pivotally coupled to the lift vehicle, the method comprising the steps of: (a) monitoring a vertical load on the rear axle; and (b) managing boom lift down speed based on the vertical load: wherein step (b) is practiced by managing the boom lift down speed according to speed parameters including high speed low speed and creep speed or stop, wherein the lift vehicle comprises an operator input device, and step (b) is practised by managing the boom lift down speed based on both the vertical load on the rear axle and anticipated operator demand according to a signal from the operator input device, characterised in that; upon a determination of the anticipated operator demand for boom lift down speed, step (b) is practised by: setting the lift down speed to a low speed parameter; determining whether the rear axle load stays above a first value for a certain period of time, and if so, ramping up the lift down speed to a high speed parameter, and if not, maintaining the lift down speed at the low parameter; and determining whether the rear axle load becomes less than a second value, and if so, ramping down the lift down speed to a creep speed or stop parameter. (a) monitoring a vertical load on the rear axle; and (b) managing boom lift down speed based on the vertical load: wherein step (b) is practiced by managing the boom lift down speed according to speed parameters including high speed low speed and creep speed or stop, wherein the lift vehicle comprises an operator input device, and step (b) is practised by managing the boom lift down speed based on both the vertical load on the rear axle and anticipated operator demand according to a signal from the operator input device, characterised in that; upon a determination of the anticipated operator demand for boom lift down speed, step (b) is practised by: setting the lift down speed to a low speed parameter; determining whether the rear axle load stays above a first value for a certain period of time, and if so, ramping up the lift down speed to a high speed parameter, and if not, maintaining the lift down speed at the low parameter; and determining whether the rear axle load becomes less than a second value, and if so, ramping down the lift down speed to a creep speed or stop parameter. wherein step (b) is practiced by managing the boom lift down speed according to speed parameters including high speed low speed and creep speed or stop, wherein the lift vehicle comprises an operator input device, and step (b) is practised by managing the boom lift down speed based on both the vertical load on the rear axle and anticipated operator demand according to a signal from the operator input device, characterised in that; upon a determination of the anticipated operator demand for boom lift down speed, step (b) is practised by: setting the lift down speed to a low speed parameter; determining whether the rear axle load stays above a first value for a certain period of time, and if so, ramping up the lift down speed to a high speed parameter, and if not, maintaining the lift down speed at the low parameter; and determining whether the rear axle load becomes less than a second value, and if so, ramping down the lift down speed to a creep speed or stop parameter. setting the lift down speed to a low speed parameter; determining whether the rear axle load stays above a first value for a certain period of time, and if so, ramping up the lift down speed to a high speed parameter, and if not, maintaining the lift down speed at the low parameter; and determining whether the rear axle load becomes less than a second value, and if so, ramping down the lift down speed to a creep speed or stop parameter.