Building a bracket & clamp setup to mount my rack & pinion to the straight axle. Will clamp each side with 4 bolts and run a bar to each side to further prevent sideways movement. Anybody have any advice or picts of how they did this. Will post my picts when I get them. JIm
THey who, nobody does this, it's not recomended or close to traditional. The bigest problem is the stearing shaft would have to move with the axle, so with the angle needed to make the connection it would have to move up and down and back and forth. The only stearing coupler designed to do this was a flexible shaft used on the early Pinto front ends. Not a big hit! Do yourself a favor and rethink what you have there and build a stearing system that will be safe and function correctly.
Thanks for the imput. Thats why I posted. Some of these have been used on 47-54 chevs and even some tech info on the Stovebolt site. Will be pointing the steering shaft almost flat so the up & down slipping movement will be minimal. Hell driveshafts do this all day every day. I think there is a late model suburban that used this kind of "slip joint?" too. try this link www.stovebolt.com/bboard/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=2;t=010758 Not saying you guys are wrong, just getting all the info I can Thanks Jim
Another design that I have seen that would work is a 91 Ford Festiva r&p mounted to axle. use a slip joint from a 95 Mustang toallow it to move up and down so it wount cause bump steer. Also make sure that the steering shaft is even or at the same level as the front springs
This subject has been brought up before and we have hashed it out. This is not a very good design because of a few things. A, You are adding unsprung weight to the front end that will negatively affect your ride quality. A minor point maybe but still valid. B, Your steering universals are now going to have to deal with suspension movement and therefore have to absorb shock loads not normaly ascociated with steering. C, Your steering universals may be forced out of thier designed operating range possibly causing bind or failure. D, Your steering slip shaft will also have to absorb suspension movement and could bind or wear prematurely. Again not a suspension component and not meant for this application. E, Your steering column bottom bushing will now have to resist the collapsing and extending steering shaft because of suspension movement. Again something it was not designed for and will wear out prematurely causing excessive slop. F, You WILL have a form of bump steer. As the axle travels through it's range the steering angle will change slightly if you hold the steering wheel rigid. If the axle articulates or the body rolls over on the supsension the steering wheel must match the opposite angle of movement or you will induce unwanted steering. G, Your rack choice my also limit your steering angle (ie. dramaticaly increaced turning circle). Most rack and pinions are designed for IFS suspensions and have short steering arms. Your stock arms are considerably longer requiring more travel to gain the angle needed for tight quarter steering operation, something a recirculating ball screw steering box is designed for. H (AMB), looks like crap and not traditional. Much better and safer ways to steer your car.
36-3WINDOW I have made this type of slip joint using a stock GM double D hollow shaft slid over a GM solid shaft with the flat on each side of it. This seems to work very well. As far as the movement of the rack input shaft is concerned---I used a Borgeson universal attached to the end of the rack input shaft, a straight run of shaft (with the slip joint in it), then a second universal, with a support bearing directly behind it. This allows the axle and rack to move around (it doesn't really move that much on a straight axle front end). The universal allows the movement and the slip joint takes up any length changes.
yeah, the late suburban slip joint works well. i'm using an old plymouth horizon rack mounted to my axle. it may not be traditional, but it will be fine with me. no brake diving, rut hunting, or bumpsteer. i don't mind eliminating any of those.
i have seen the GM double D shaft and the hollow shaft used in this application before...but i have always thought that since they are not heat treated and are soft that they would wear out quick i'm sure your setup works fine..i'm just concerned about any wear many years later is the Surburban or Mustang slip joints mentioned really designed for this use ? any pictures? depending on how the steering is setup and the angles of the steering shaft , i would think you could possibilly get a couple inches of movement
the suburban joint is made for this purpose. i'll see if i can find a picture. we did one the way brianangus talked about, we just put a zerk fitting in it to lube the joint.
36-3WINDOW The intermediate shaft with the slip joint in it sets almost dead-nuts in line with the rack input shaft. Even though the axle may move up or down, it only moves a maximum of +/- 1 1/2" up and down. This translates to a sliding movement (at 90 degrees to the axle movement) of only a few thousandths of an inch. The mating (sliding) surfaces of the double D tube and shaft are about 2 1/2" long. I expect that I will die of old age long before any signifigant wear appears at this sliding surface.
the company "no limit engineering" has developed a straight axle mounted rack and pinion steering setup. you may want to check out their website and some of their recent magazine articles (i believe are referenced by their site). the photos of the setup and how they handle the shaft - joint problem may be helpful. i am leery of such a setup but always appreciate new thoughts and tech stuff. good luck!
UH, No it isn't. It IS meant to absorb the movement and flex between the body and the chassis, not suspension movement. In fact I challenge you to show me a factory OEM system of this type. Rack mounted to axle that is.
elpolacko, i misstated myself. it's not made for this purpose, but it does work well in this application. your knowledge of suspensions and such is far greater than mine i'm sure, but having driven on this type of set-up, i know it works well. i'm sure there are better ways, but this one works good enough for me. i dunno if there was a factory setup like this, and i'm not trying to challenge you to anything, i was just trying to answer the questions others were asking.
MAN, THIS IS WHAT THE HAMB IS ALL ABOUT!!! My dad & I decided a long time ago that you get as many opinions about a subject and then make up your mind. I know now I have to do a little checking into some of the stuff I've been told, but now I know where to concentrate my efforts! Thanks Hamb & Hambers Jim
My '38 Dodge pickup with beam axle and Geo Rack, My '31 A sedan with beam axle and Geo rack and my '38 Fiat with Magnum tube axle and Sirocco rack all work very well and have for many miles. A double d shaft and sleeve works. The movement in the slip joint is about 3/8".
Iwas going to use this type of setup when I first started my project. I had the rack mount fabbed and the rack attached to the axle and was pretty confident that it can be made to work ok, but the more I looked at it I just didn't like the way it looked so I pulled it all and went with a cross steer. Just better looking IMHO.
Friend of mine has a setup like you are asking about on his 34 coupe with split bones, Mopar rack, Borgenson joints and some form of OEM intermediate slip shaft and has over 50K on the car with no problems.
Personnally, I would listen to Elpolacko, as the man knows what he is talking about when it comes to suspension systems, especially IFS systems. When you start using components like steering universal joints for things they were NOT designed to do, you are asking for trouble. They will probably fail at the most in-opportune time, like when you are going down the road at 70 mph and then you will have NO steering. Ooops! If you want to use a rack and pinion type steering, and not be mis-using parts and not have bump-steer, look at the Unisteer unit. It is basically the right half of a rack and pinion unit. It bolts to a Vega steering box mount on the left frame rail and the right end of the rack bolts to the steering arm of the right spindle. Look here: http://www.unisteer.com Maybe Elpolacko will weigh in on this option. He and I have not talked about this unit that I can remember.
Can the idea be used, of course it can your testimonials prove it. Likewise, other less than stellar modifications have been done with thousands of miles on them like the famous "two link" or Z link rear suspensions the mini-trucker guys are fond of. But that still doesn't make them correct or safe. Two things I would never screw around with is steering and brakes. Loose either one and you are screwed and potentially dangerous to others around you. The only precident for using a rack mounted in the manner this post is concerning is farm equipement. Hardly highway worthy. Your friends and aquaintences may very well have 50K miles on one of these systems. Does he know how much longer it will last? Is he just lucky or does he really know about the system he created. I myself would rather not depend on luck so I stick to proven designs that are widely accepted by OEM and aftermarket manufacturers. All it is going to take is one high profile mistake. Just one guy to make the news big enough before the Fed's, State or Local governments start peering over your shoulder and policing what you can or cannot do. Our Aussie and Euro friends could tell you stories for days about tech inspectors and regulations forced on them, limiting what is and what is not acceptable. Example: Ever notice the abundance of four bar front ends on Aussie cars? Split wishbones and hairpin radius rods are not allowed because of a single point connection with the frame. I belive there are exceptions to the rule but they are few. Here we have been using such an arrangement since the inception of the hot rod, we have precident. There is no precident for axle mounted racks, and for good reasons like I stated before.
its the best way to do it,lots of class A motorhomes have a steering BOX mounted to the axle,with a slip joint running to the steering wheel. this is not a new or dumb idea,hellif you don't want to use a rack and you want cross steer,mount a steering box of your choice ON the axle. Randy
Randy, I will admit I don't know that much about motorhome chassis but I question this claim: I just spent a few minutes searching around the internet and could not find one example. The best I could come up with was a "Class A" chassis with a front mounted inline Cummins and "engine mounted" steering gear. Since most of the Motorhome chassis A,B and C class are either derived from medium duty pickup chassis or heavy fleet such as Frieghtliner components, frame mounted steering systems are very common. But in all my attempts to prove you correct I could not find any. Could you show me or at least list a manufacturer that does mount a steering gear directly to the axle? I would like to see it, seriously.
I had a Model A roadster (Boss 302, 4 speed, 9 inch) with a tube front axle and R & P atttached to the axle. Used the GM slip joint like Brian says. I ran this car ten years like this. Lots of high speed driving (and racing). Absolutely zero problems with this set up. No bump steer. As far as I am concerned this is a good set up and would do it again if I built another car.
could a guy put in a cross member (provided there is sufficient room)either in front or behind the axle and mount the rack and pinion to that so its in a fixed position and have no need for a slip joint? the tierods would move up and down like and IFS system in which the rack is mounts to the crossmember and doesn't move with the A arms
mounting a rack and pinion to the frame of a car with a straight axle is absolutely the worst thing that could be done..i'll leave it at that
I wanted to mount a rack to my i-beam. the guy i bought my axle from said they do that on midgets. I would think if it could stand up to a race car it should be safe.
There seem to be a lot of people out there that think that if something works on a circle race track it should work on the street. What they fail to understand it that most oval track race cars get the suspension checked before every race night. Then most are subjected to less the 50 miles of use per night. Even at that parts fail. The difference is when parts fail on a race track all the incident is contained to the track, where everyone is going in the same direction, most of the time. When the parts fail, the race crashes into a wall and other cars and may get distroyed, but there are roll bars, and a whole list of things in there designed to protect the driver. Race cars have no passengers, and no pedestrains. Your street car has very little protection for the driver, is opperated on a street with unprotected pedestrains, and cars traveling in the oppisite directtion. Most street cars have the suspension checked only at oil change time or at the begining of a hot rod season, and a lot of them don't even get checked that often. Steering failure often ends in a disaster. A disaster on the race track ends with a distroyed race car. A disaster on the street is just the begining of one or more ruined lives. To think things that are done on a race car are OK for the street is short changing the consequences of the risks. They are not the same. We used to do things on the race track that I would never even consider doing on the street. We comprimised on so many things on the race car to gain a little advantage over the compitition, some were just plain nuts. To even think some guy saw what we had done on our race car and thought it was cool to do on the street scares the hell out of me. My family and I use the same streets. Gene
The Jalopy Journal
