What is the advantages of R&P?

All power steering types need a pump. Wheter "power steering" or "power rack". That is where it gets the power assist. I sugest you do a search for the info you are looking for. There are so many options that you will never get one straight answer on this. Or, be more specific on what type of power rack conversion you are looking at.

A rack and pinion is a complete replacement of hte worm and sector gear box. Your entire steering system ( gearbox, pitman arm, idler arm centerlink...) gets replaced. Advantages? Tighter, easier (IMO) steering. Much more control of the direction of the car on smooth surfaces. Now, downsides (these mostly depend on which rack you use) potential for horrid bumpsteer (you hit a bump and the direction of the car is changed. This is due to catastrophic alterations to the suspension geometry.) , increase turning radius.

Weight is also another potential downside, though the weight difference in negligible in my opinion.

Did I get that right ronstang?

The main advantage to R&P steering is fewer parts, thus the potential for those parts to wear out and thus have too much slack in the steering.

I think it may be important to describe the components of the rack and pinion as compared to the stock steering box and centerlink.


1. The pinion is simply a gear.
2. The rack is also a gear, but instead of being round, it is flat. Think of a typical round gear that has been split one side and laid out flat.

How do these parts work together? The pinion is basically attached to the end of the steering shaft...the steering shaft is actually coupled to a short shaft on the rack and pinion assembly with the pinion gear being inside the rack. Anyway, when you turn the steering wheel, the pinion gear turns the same direction and the same number of rotations. This pinion is in contact with the flat rack gear. As you turn the wheel, which turns the pinion, the rack moves linearly. The rack is attacked to the inner tie rod ends and thus the tie rods and finally the steering arms on the uprights. Hopefully from this description, you get the idea that the relationship between the steering wheel and rest of the steering gear in a rack and pinion system is very direct.


The steering box is a worm and sector system with recirculating balls. Basically, the gears in the stock steering box do not come into direct contact. Bearing balls ride inbetween the input gear and the output to the pitman arm. This is a big part of the sloppyness of the stock system. This system isn't too bad, still not as good as R&P, when it is new or well maintained. However, as D. Hearne said, there are a lot of parts to foul up in the steering box system. You have the gears, bearing balls, the housing itself , etc...

The pitman arm is the arm attached to the steering box. The idler arm is on the other end of the center link and is attached to the chassis. The tie rod ends attach to the center link. When you turn the wheel, the worm gear in the steering box turns, acting on the bearing balls which in turn move the sector gear. The sector gear outputs to the pitman arm which in turn moves the centerlink, tie rods, and finally the steering arms and wheels. Whew... that was a mouthful. If I missed anything, let me know.

As I noted in the above, a well maintained steering box system will be pretty good and is much cheaper than converting to R&P. The cheapest kits seem to be around $1k+. My suggestion, if you are having sloppy steering look into buying a new or rebuilt box, new tie rod ends, sleaves, and maybe strut rods.

Good luck

Also remember that there's a "rag joint" in the steering that can add a considerable amount of play. That's another part to check and replace. It's pretty inexpensive.

I think that from a driver's standpoint, the rack offers very good feedback. That is you don't feel quite as "disconnected" from the front end as you do with a classic Mustang steering box. While I like the idea of my '68 handling like my '88 I'm not ready to part with the cash needed to buy one. Also, there are some bad points of a rack, such as bump steer if it's not 100% due to the rack and lower control arms pivoting in different planes, and increased turning radius. That last on makes driving my '88 GT a pain, since our Suburban will actually make a tighter U-turn than the GT.

I don't believe '65's have "rag joints", I believe they started in '67.

I've got a manual rack and pinion and would not do it again; I would rebuild the existing steering system. The R&P does have a nice feel, but I'm not sure it was worth the money and the turning radius is a big dissapointment.

Tim

65 fastback said:

I don't believe '65's have "rag joints", I believe they started in '67.

Tim

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Yea the 65-early 67's had the deadly spear pointed directly at your chext. I've never had a rag joint that had all the slack that Hack mentioned. But still not a bad idea to replace one that's 30 something years old.