Posted by leo | Posted in Car Development | Posted on 28-08-2010
While researching simplification mods for our new motor, I decided to take a look into the steering rack as well. We were never thrilled about running the power steering pump. There was a manual rack that came one some 2nd gen rx7s but the steering ratio was horrible. The steering ratio measures how much input you need to give on the steering wheel for the wheels to move. A “quick” steering rack requires less input in the wheel which is ideal for our purpose. So the “slow” manual rack wouldn’t work. Taking out the power steering will also require more force to turn the wheel. Parking could be a bit of a chore, but once we are up to speed we won’t even notice. Due to an annoying beep from the power steering ECU at Spokane (due to the steering angle sensor, which was plugged in) we disabled the ECU. We actually ran that whole race without power steering and no one even noticed. Now that I have a little more time on my hands, its time to do something permanent with this steering. Apparently miata racers have been doing this for years. I followed these instructions from rx7club http://www.rx7club.com/showthread.php?t=440198.
We had a spare steering rack out of the white car. My plan is to mod that rack and install it when we put the new motor in. I went out to the tarp tent where the ChumpCar and discovered that a furry friend had decided to make its home there (just a cat!).
First off, time to get the steering rack off the front subframe.
Looks like the semi that hit this car bent one of the tie rods. That will have to be replaced.
6 quick bolts through the bottom to release the steering mounts (with the bushings inside). Don’t just hit the nuts with the impact gun, they are welded on to make it easier on you. I make this mistake.
Bare rack.
Next, remove the tie rods. Take the boot off first. Since this tie rod was going to be replaced anyway, I cut the boot. It’s important to have good boots so that the parts stay well greased and clean.
Next, I removed the steering knuckle.
Then I removed the locking nut and cover on these two access areas.
After removing a plastic dust cap, a snap ring needs to be removed from the top of the spindle. It took me forever for some reason. I even had the correct tool.
Next the spindle can be tapped out gentle from the bottom and removed.
Remove the lock pin on the passenger side end cap (by turning clock wise until the lock pin pops out and then counter-clock wise until it is removed). The main shaft can now be removed. Give it a good tug and it will pop out.
Slide the larger carrier bit off and the lock ring bit at the end. All that will be left is the offending pneumatic seal. All this work is to get this out of the system.
I prep’d the vise and got to work with the grinder.
Success!
Leave the little lock collar on the rod. Next up, removing the fluid lines from the housing. Since there will no longer be power steering fluid in this unit (just grease), all these holes need to do is be well cap’d to prevent dirt and water getting in.
A hammer finished these off nicely.
For the ports to the pump its self, I managed to find hardware in our box that matched the treading. They were unfortunately too long, so I got out the dewalt bolt shortener.
For the line feeding the cooling loop, I found our spare loop and cut off the fitting that normally goes there. It got the same hammer treatment.
Now it’s time to put everything back together. The carrier bit slides back on the main shaft. Apply a ton of grease.
… and reinstall.
Reinstall the lock pin.
Grease up the spindle and reinstall.
Lock washer goes back in.
On the bottom reinstall the nut (25ft-lb) and the housing cover (35ft-lb).
Before reinstalling the tie rods, make sure these little pins are pushed up.
Assemble the last door, half circle washer thing, spring, cover. Tighten the cover to 43ft-lb four times. Then loosen one quarter turn. Then tighten up the lock ring while keeping the center tight. If you were an idiot like me and striped the nut, apply grinder until the 14mm head becomes a 13mm and swear a lot. Reinstall tie rods.
Nearly done! The only thing I have left is to install the new tie rod and put it into the car. Great saturday project. Bench only projects make me happy.
