Oct 05, 2021
This is kind of an interesting puzzle and I'm sure there are some people that will get it immediately and there are others that won't ever get it. This is often the case. I tried this on my brother and he scratched his head for 20 minutes and left a big hole in his forehead.
A while back, I got a call from an anxious do-it-yourselfer. He was doing a clutch on his Honda. I think it was like a 1981 Honda Accord. Or an 82 or maybe even an 83.
Anyway, he and his mother-in-law were out in the driveway and they had the thing jacked up and were attempting to remove the transaxle.
This is what front-wheel drive cars have. They have the transmission and the axle assembly and the final drive assembly in one big box called the transaxle. I order to replace the clutch, you take that whole thing out and then you put your new clutch in, you put that whole thing back in, you shove the axles back in, and you put the tires back on and a month and a half later you drive away.
He called me up and he said, “I’ve got a problem.” He said, “I'm attempting to take off the transaxle and I've got power steering fluid coming out of the transmission.” Whoo. He said what is power steering fluid? He said, “Is that the lubricant that's in the transmission?” And I said, “No! What's in the transmission is 10W40 motor oil. The lubricant is for the gears in the transmission.” He said well why is the power steering fluid going into the transmission? I pull off these hoses and power steering fluid comes out of them.”
And I said, “HmmmmMmmmmHmmmmmMmmmHmmmmmmm.” Anyway, just fill in the blanks and you'll have the answer. So, what did I say to this anxious do-it-yourselfer?
I got a call many years ago from an anxious do-it-yourselfer who was doing a clutch job on his Honda. Anyway, he and his mother-in-law are out there in the driveway taking the transmission out. And they have the thing jacked up and had pulled the axles out and drained the transaxle oil and they noticed something. So he called me up and said, "Something funny is going on! I've got these hoses that are connected to the transaxle. And when I pull them off power steering fluid comes out!"
And he asked me if this stuff was lubricating the transmission. And I said "No, you drained out the stuff that was lubricating the transmission, which is motor oil. That's what lubricates the transmission." So our puzzler question was: Why is there power steering fluid in his transmission?
So it actually does make sense, because Honda had a very interesting design called variable assist steering. When do you want the greatest amount of power steering?
When you're trying to park. And when do you want the least--or put another way, when does power steering create the biggest disadvantage?
That's when you're trying to drive at high speed. You don't want power steering when you're trying to drive at high speed, because you want to feel that road.
So variable assist power steering is when you get a lot of power steering when the car is standing still, and just a little bit of power steering when the car is going fast.
And Honda figured out that one of the easiest ways to do this is to pump that power steering fluid into a valve in the transmission so that the faster the final drive turns--that is the gears that eventually drive the wheels--the less pressure goes to the power steering rack and pinion. So you get diminished effect of the power steering when the vehicles moving at high speed. And as soon as the vehicle begins to slow down you get increased power steering. And you end up with the most powerful steering when the vehicle is what stopped but the engine is still running.
