How does the AWD work on the 2003 CR-V?

[Steven Holmes]

Hi

I have a 2003 AWD CR-V. I know how the system works technically, but what I am wondering is, when wheels begin to slip, and the AWD kicks in, how long does the car stay in AWD for? In other words, once AWD starts up, does it stay there until I brake, until the car slows to a stop again, until the engine is turned off and then on?

Curious.

SAH

 

[null_pointer]

Hi

I have a 2003 AWD CR-V. I know how the system works technically, but what I am wondering is, when wheels begin to slip, and the AWD kicks in, how long does the car stay in AWD for? In other words, once AWD starts up, does it stay there until I brake, until the car slows to a stop again, until the engine is turned off and then on?

Curious.

SAH

I recently read somewhere that there are two small oil pumps, one driven by the drive shaft, the other by the rear wheels. Their output is directed to opposing sides of a piston. When the front wheels slip the drive shaft pump turns faster causing the piston to move causing a clutch pack to engage the rear wheels. As soon as the wheels are turning at the same speed the oil pressure on both sides of the piston equalizes and the piston returns to it's central position and the rear wheels disengage. Don't take this as the gospel truth...it's just something I read on the internet.

 

[Scott MacLean]

I recently read somewhere that there are two small oil pumps, one

driven by the drive shaft, the other by the rear wheels. Their output is directed to opposing sides of a piston. When the front wheels slip the drive shaft pump turns faster causing the piston to move causing a clutch pack to engage the rear wheels. As soon as the wheels are turning at the same speed the oil pressure on both sides of the piston equalizes and the piston returns to it's central position and the rear wheels disengage. Don't take this as the gospel truth...it's just something I read on the internet.

Almost right. If that was the case, as soon as it engaged, it would then disengage again, slip, re-engage, and so on.

There are two pumps, as you mentioned, pumping differential fluid from the rear diff. One pump is in the transmission, the other runs off the rear diff. The drive shaft to the rear diff turns continuously, but is not connected to the wheels in normal driving, which keeps mileage up. When the front wheels turn faster than the rear, there is a pressure differential between the pumps, and a multiplate clutch in the rear diff system engages, transferring torque to the rear wheels. This clutch remains engaged as long as there is torque available. As soon as you let up off the gas, the clutch disengages and you are back in FWD mode.

 

['Curly Q. Links']

Hi

I have a 2003 AWD CR-V. I know how the system works technically, but what I am wondering is, when wheels begin to slip, and the AWD kicks in, how long does the car stay in AWD for? In other words, once AWD starts up, does it stay there until I brake, until the car slows to a stop again, until the engine is turned off and then on?

Curious.

SAH

Nul_pointer is right.. (if it's the same as the 1st generation CRV) two opposing pumps inside the rear diff. If front or rear wheels spin faster, the rear diff locks up to transfer torque to whatever is slipping. It's over as soon as it starts because your wheels all start turning the same speed right away. Great at icy intersections and snowbanks.

If you lock up the rear wheels on a AWD CRV, the fronts will lock up too (almost completely). In other words, you can't put it into one of those 'park-brake-skids' that I used to find so handy for burning a U-turn on my icy driveway. :-(

Honda.com has resources that explain this.