Has any of you ever used a rack and pinion on a striaght axle with the rack fastened to the axle if so what type of slip joint did you use ?
No i haven't. I may be wrong, but the thought of a slip joint going to a rack affixed to a straight axle gives me the chills....is this actually common practice,(nothing you Amercians do suprises me any more!) or a "what if?" idea you had?
I really have to ask why you would even bother? It would be super ugly for a start, untraditional and the slip joint sounds dangerous. Doc.
R&C did this years ago with a collapsible GM column with the plastic rivets drilled out, but there's not a lot of metal in sleeve to wear.
I saw one done on a yellow 56 chev about 6 years ago, it didnt look right... I had my friend take a pic (I didnt have a camera with me) and he never gave me the pic... It was in the nw burbs of chicago.. I forget what show it was.
Rack needs to be mounted to a solid piece of the chassis level with the axle center line NOT to the beam!when this first started people were using the flex shaft out of pinto steering columns the cable ones as soon as they started showing up Every chassis guru in the country was in some mag getting quoted on all the reasons that a beam mounted set up was wrong and deadly
We do this on supermodifeds all the time. Have zero problems with it in a racing environment. But, this is a tube axle, built with this in mind, not an add on to an I-beam axle setup. I don't see why it wouldn't work on the street. The reason for this is while we pay a little penalty in unsprung weight, bump steer is minimized. You have a couple options for slip joints. Borgeson makes a "double-D" setup, which I have used. They're about $70, and work OK. Woodward makes a splined setup that has about 3" of travel, and they're about $150. Given the choice I would use the Woodward piece. The double-D setup starts out really tight (doesn't slide well) and develops slop over time. Here is a photo of the Borgeson joint installed...it may be a little hard to see through all of the diagonals in the frame. The rack & pinion is a Ford T-Bird sport rack (quick ratio) used in the T-Bird super coupes.
I wouldn't say it was dangerous in operation. Supermodifieds have been using axle mounted racks at speeds up to 160 mph for years now. Good idea for a hot rod? Hard to say. I guess it would depend on clearance for the intermediate shaft, tie rods, etc. Also, how well is the rack mounted to the axle beam. Traditioal hot rod tech? Definetely not.
I put a Pinto R&P on the axle of my 32 coup and ran it for years at El Mirage, Bonneville and the drags with no grief. Used the Pinto flex thing. Inspectors for SCTA hated that thing. I always said that millions of them were running around in Pintos hitting pot holes and curbs and what not with out comming apart. When I retired the 32 SCTA put in a "No Pinto wire rope steering" rule.
There are several around our area that have been well tested with no problems. Not traditional but functional. First one I was aware of was for a physically limited person who needed power steering on a 32.
You could probably do a lot better, appearance-wise than the T-Bird racks. I think Ashley Webb's roadster has a Strange dragster rack, but I cant remember if it's mounted to the chassis or the axle. It is either painted or anodized black, and blends in well with the rest of the car. Most racks actually built for racing are a lot smaller and easier to hide (a lot more expensive, too! )
Unisteer makes a small unit that has only one link rod going to the passenger side, and would be almost invisible behind a straight axel. Checkout the site.
Was just talking about that setup with the class. I don't care for the mount for anything but skinny front tires. Not a lot of side support, and still not traditional...
The Pinto flex shaft was not for the up and down movement you get from an axle mounted rack it was used as a flex drive because of the angle the Pinto column is at in a stock body.the passenger side of the wheel is father forward than the drivers side.The cable worked in the same fassion that a flexable carb screwdriver works.or the cable type socket flex joint.Looks like I was way off base with because just about the time I was thinking of trying it is when there were several articles on how dangerous this was lots of street rod shops saying it wasn't safe mabye I miss understood and it was the use of the Pinto flex cable that was n't safe one had a pic of a severely frayed cable that was caused by being used for this
this is going on mercury meteor with a tube axle ugly does not matter the thing is a freak and will be driven alot and want it to last
Mack used to mount the steering box on the I-beam axle of one model of their trucks back in the 70's. It was never widely accepted and they dropped it but those trucks had zero bumpsteer and drove a lot better than their contemporaries...
Here is a rack and pinion bolted to a solid axle on a 32 roadster. The car turned and steered as good as any 32 I've ever driven.
GM buses also had the steering box on the axle. And a bevel gear drive at the bottom of the steering post. The connection to the bevel gear to the axle mounted box was a drive shaft with slip joint. NO bumpsteer. Never seen the Mack version. Later GM's (after 74) used a Sheppard box on the axle, the same box Mack used on their frame mounted steering.
It was common to mount a rack on your Axle in the mid 70's.I had a Morris Minor rack mounted on a Super Bell tube axle in a '32 Phaeton . Worked fine, it was the 4 bar mounts that were welded to the axle that were a problem. Weld broke and I lost steering , rear ended a car at about 25 mph , the Super Bell tube axle broke from the impact and I wrecked my nice car . It had won Rod Sweepstakes , Best Paint and Best Stock Bodied Rod ( the Doug Doyle Memorial Award) at the 1977 Portland Roadster Show . The car was in Street Rodder , Feb 1978 after I fixed it .Take a look at that issue and see a nice car that could be built for under $20,000 in 1975-'76 .........
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