Rack and pinion

Unknown

Has any one installed a rack and pinion set up in their stepdown. If so do you have any pics?

[Deleted User]

Jim it is difficult to install a rack and pinion on a stepdown and still maintain the original suspension components. I have heard of one HET member doing it but after talking to him he said on rough roads you get bump steer. You can replace the complete front end stub with one from Fatman and install that way.



As an alternative take a look at my site and on the front page you will see a link to a news item by Ray Barker. Ray is a fabrication wizard and he has come up with a power steering option for stepdowns that keeps the existing steering but adds powersteering using newer components and you do not get bump steer.



Take a look I have also posted pictures he sent. I think its a great option for those of us who want power steering but do not want to replace everything to get it.

Unknown

not sure what bump steer is. I had an old time hotrodder look at the 49 coupe yesterday and he said that the steering setup looked to be a very easy candidate for rack and pinion, either power or non power. He suggested removing the center steering pin and tie rods and building a couple of brackets to hold the rack, another bracket to support the steering column at the bottom then its just a matter of hooking up a steering linkage from the bottom of the steering column to the rack with a couple of u-joints. Said he's done it on a lot of different cars and works great.

[Deleted User]

You will find if you do that with the existing front suspension you will get bump steer. Bump steer is when the car steers itself without input from you. Its caused by bumps in the road interacting with improper length or angle of your suspension and steering linkages. You still have to use tie rods to link your rack. This is where the problem comes in you have to find a rack and tie rod combination that match the steering geometry of the Hudson.



I have been looking for 2 years for a boltin kit and I even contacted Fatman Fabricators they of course told me to buy their weld in stub. This replaces everything on the front-end A-Frames, linkages, brakes everything.



If you and your hotrodder friend can get it working with the existing Hudson front-end without bump steer let me know I want to know how you did it.

Unknown

I wonder if some of the engineering types here would be able to figure it out. I wonder also if a powered rack would be less prone to bump steer. Also has the bump steer been noticed on bias ply or radial tires?

[Deleted User]

Same on both powered or non-powered. And with radials. It has to do with maintaining the correct steering geometry in the arc of the turn. In the setups I have seen the rack changes the relationship between the tie rod travel and the suspension arc. So during travel on a bumpy road if the length of travel on the tie rod does not exactly match the suspension arc you get momentary toe in which changes the direction of the car. The guy I talked to who did this said he was not really bothered by this.

I am not saying that this is impossible to eliminate or its impossible to engineer this into the existing hudson suspension I personally have not seen it done. I believe the problem is that those who have tried have been using parts from existing vehicles and trying to make them fit. I have been looking at this problem myself and I think that you could map the suspension arc to the tie rod travel and design a matching relationship by machining a new rack and pinion that exactly mimics the existing steering geometry. That been said it would be a bear to install in an Hudson that maintained a stock engine. I spent a lot of time under my Hornet measuring for this and I couldn't come up with a clean way to mount anything extra.

At the end of the day the fact is the Hudson steering is pretty darn nice as is. Adding a rack will not make it handle any better but will reduce the number of turns lock to lock to steer. You can get the same benefit from doing what Ray Barker did and replace the steering box and add power steering that way while maintaining the exact steering geometry that Hudson designed for the stepdowns. I am going to talk nice to Ray and see if he will let me drive his car to see what its like.

[Deleted User]

I actually looked into this when I first got my Wasp. I was kinda opposed to stubbing it due to cost, and I did observe the merits of the original Hudson front end. I was kinda afraid the Mustang II options weren't substantial enough for the weight of the Hudson engine, where alot of transplanted engines are much lighter.



There is a rack and pinion option, that may surprize you. The '90s Chrysler Concorde, and other mopar variants of that body style, used a "Center take off" rack and pinion steering system. I spotted one in a junkyard and bought it for $10 just to do some measurements etc.



The result was, the distance between the center tie rod ends are exactly the same, and the length of the tie rods is also the same. This means that one could use Heim Joints to mate up the existing tie rods to the Chrysler "Center take off" power rack and pinion.



The task then becomes mounting the rack in a situation where the steering can be attached. The position of the steering pinion vs. the center take off/center point is such that the pinion is nearly vertical if the tie rods are installed at the same angle as original. This option is a possibility however, with the fabrication of a piece to remount the "center point" to a different angle which would allow a joint/shaft to be run from the existing column to the pinion. The actual mounting of the rack doesn't look to be that difficult, and the "clocking" of the tie rods and pinion may very well be addressed by its mounting rather than fabricating a piece to change the tie rod attachment on the "center take off".



The common rack and pinion arrangements do not have tie rod ends long enough to avoid "bump steer". The pivot of the tie rod would have to more nearly match the pivot point of the rear of the A arm. This is why Hudson went with the center point steering in the first place, the rear of the A arms is very close beneath the bottom of the car. If you notice your Mustang II front ends, they have A arms that are very short with the pivot of the rack's tie rods more nearly matching the pivot of the A arms.



Ray Barker's approach is unique, and kinda set my mind to thinking. I'm sure it works fine with a V8 transplant, but I'm kinda wondering how it might interfere with a Hudson 6 sticking on up into that area.



Mark Hudson

[Deleted User]

Yes Ray has noticed that and is working on a modification to allow it to fit in with a stock hudson engine.

rambos_ride

Jimalberta wrote:

Has any one installed a rack and pinion set up in their stepdown. If so do you have any pics?

First off - Jim - did you and 51hornetA get together and see what avatar to wear?

Has anyone thought of trying one of these types of steering racks out?

http://www.mckinneycorp.com/catalog/steering/steering1.html

They are centerpoint racks and I was wondering if someone thought this style could be used?

Unknown

Hi Dan, the avatar was just the easiest thing to put on for a computer non-geek. The center point rack you displayed would have some clearance issues I believe as my oil pan doesn't clear the tie rods by much. We were thinking of using a rack with the steering connection at the drivers end so as to make for a cleaner and neater install . With the ability to remove the stock steering box and pitman arm and drag link it would clean things up quite a bit to make room for headers, etc.

Unknown

I tried to make sense of Rays pictures but they are so dark that I can't make out what he did.

[Deleted User]

rambos_ride wrote:

First off - Jim - did you and 51hornetA get together and see what avatar to wear?



Has anyone thought of trying one of these types of steering racks out?



http://www.mckinneycorp.com/catalog/steering/steering1.html



They are centerpoint racks and I was wondering if someone thought this style could be used?

Evidently Dan, you didn't read my post above. LOL



Clearance under the stock Hudson 6 is not an issue for the centerpoint racks. It may very well be one for you engine swappers. From the pictures I've seen of your swaps, it gets crowed right at the point of the centerpoint fulcrum already.



Mark

[Deleted User]

Jim did you read the description he posted on the front page of my site?

rambos_ride

Jimalberta wrote:

I tried to make sense of Rays pictures but they are so dark that I can't make out what he did.

Ditto Jim!

I even turned up my monitors brightness but the pictures didn't reveal anything of real interest to someone trying to figure out what he did by the description in the article.

Although I haven't been particularly inclined to try and splice in a power steering setup - since I went to great lengths to keep the original steering and suspension (while nearly doubling the the CUI from 254 to 454 !) - once I do drive the car I may decide otherwise...

If Ray doesn't have a good digital camera to take better close up pics - maybe he could borrow one from a family member or friend - I will say from what I could make out of the picture it looks like Ray does some nice quality work...

Unknown

From what I can make out he put the steering box quite far forward and then must have gone across the front and then back to the center pin some how. So the shaft from the steering column to the box must travel above the control arm. This is all just a guess.

Unknown

I've also noted that most heavier cars don't have rack and pinion steering and I've never seen a truck with it so maybe its a weight issue more than anything.

[Deleted User]

Jim,



read this explanation he tells you how he did it.



http://www.hudsonmotorcar.org/News/article/sid=20.html