What happens when you run out of transmission fluid?

Answer 1

Your Transmission Fluid serves three purposes - lubricant, coolant, and hydraulic. The answer to the question depends on the scenario you are in when the fluid runs out. If a coolant line were to rupture and you had a sudden, massive fluid loss, you should be ok because with the sudden loss of fluid, you also had a sudden shutdown of the hydraulic system (no fluid, no hydraulics). Very few parts are moving at this point, including you. You would likely pull over to the side of the road and shift to park, at this point, the residual lubicant would have kept the seals from drying up and would have given enough time to shut the engine without suffering any damage. If you were able to coast for a good ways when this happened, there is a potential for damage to occur. Note that when you fix the hose and replace the fluid - you need to follow the total-fill specs instead of the typical fluid-change specs. If you had a slow leak and the transmission was allowed to operate with marginal fluid level over time, then there is a big chance for failure stemming from lack of coolant and lack of lubricant - if this is the type of fluid loss you are talking about, expect to payout.