Rack-and-pinion with solid front axles

I know it's been done:

Vintage Frazer-Nashes had rack-and-pinion steering with a solid axle. I've never seen how it was done. Presumably the rack was bolted to the right-hand frame rail and operated a drag link from its forward end.

A friend of mine from New Zealand tells me that they used to use Morris Minor rack-and-pinion under the floorboards of T-buckets during the '70's.

There are two examples from two very different contexts; but surely there are other approaches. Could I please either see some examples or hear some theories?

 

Something like this?

http://www.customclassictrucks.com/techarticles/0602cct_rack_and_pinion_steering/photo_11.html

 

do a search,saw one on here that used half a rack conected to drag link,not very visually appealing though.

 

I clear forgot about the Unisteer cross-steer R&P!
http://www.unisteer.com/mm5/merchan...duct_Code=8000460-01&Category_Code=STREET+HOT

 

Ned, this has done the rounds for decades. Back in the 70's some folks would mount a rack to the axle and have either a slip or flex joint to connect it to the column and make up for supension movement. Here in Australia some use a rack from a Camira (GM, same as a US J-car I think)mounted to the frame and their justification is that the arms on the rack pivot from the centre, therefore having decent geometry. I've workred on and driven cars with it and don't agree. More like thinking they're clever using cheap wrecking yard parts and saving on a tie rod. It also doesn't save any space and just looks wrong.

The T-bucket thing would be the rack mounted under/in the firewall/toeboard area with a single long drag link extending to the spindle replicating early ford side steering.

Unisteer now sell what is basically a side steer version of this. A one sided rack mounts to the chassis rail and a long link reaches across to the stering arm on the other side. Do a seach for it here, it's been discussed a couple of times. Some like it, some think it's out of place. I think it's un necessary, I've never found anything wrong with a normal steering box.

 

Here you go...http://www.streetrodderweb.com/tech/0812sr_rack_and_pinion_steering/index.html

 

I am using this on my Model A and love it... steers great, but is very quick to steer. I only have about 1 turn at the steering wheel so tight turns aren't good...

 

I changed out a frame mounted rack and pinion unit that was combined with a tube dropped axle. It steered smooth and fast which was too quick for the short wheel base. It also had some bump steer which was the motivation behind changing it all out. My dad and I made brackets for mounting a Vega steering box, cross steer setup, no bumpsteer anymore looks clean, and works good.

 

I have yet to see a full rack install on a solid axle car that works "right"

mounted to the axle, you need a slip joint in the steering shaft, and they Never work well, they bind.

mounted to the chassis, causes geometry issues causing bump steer.

I have driven cars set up this way that work OK, but never as good as a standard steering box, and other parts in good shape.

as a side note, we often have customers looking to add power steering to a early ford front end... many times simply greasing the kingpins makes them happy!

 

Any pic's of this set up?

 

These are the best I have right now....

 

Which is what I said, just not in those words.

 

Yikes! You got your brake line zip tied to a rubber hose?!!! Shaking, vibrating, work hardening, fatiguing, braking - followed by no braking. Better fix that.

 

I went from a Vega box to a Unisteer in my coupe. It was one of the best things I have done to the car.

 

I think the Frazer Nash used cantilevered springs like this;

with the rack mounted back near the spring mounts on the frame,
and links coming fowrard and out to the steering arms,
thus the bump steer problem was minimized.

I guess the answer to the question is more about axle location in one way,
if the front axle was tied in with a watts link,
and the place on the rack where the links out to the steering arms pivot is reasonably close to the effective centre created by the watts there is no reason why rack and pinion could not work fine with a solid axle, sure there will always be some bump steer but the amount could be made small over enough syspension travel to make it more than acceptable.

 

I have a rack from an E X P on my Model A and have been driving it 10 years now with no promblems.

 

Thanks Thunderace! That makes sense.

It doesn't account for the quarter-elliptics becoming longer on bump and shorter on droop, but then those FNs had virtually no suspension travel. It does account for their reputation for responsive steering, however, despite having no differential.

 

How is it installed? On the axle? On the front crossmember? On the frame rail?

 

I remember seeing a project in Rod and Custom magazine several years ago - a '32 Ford roadster powered by a propane fueled Ford 300 CID six and it had rack and pinion of some sort bolted to the axle, with a slip joint on the steering column. If I remember correctly it was Jake (of Pete and Jake fame) that built the car. It might even still be around somewhere.
Chris

 

That's how I always understood it. It works a fore-aft drag link as per the T-bucket norm. That would limit you to a near-vertical steering column, though (again as per the T-bucket norm) as the Minor set-up doesn't have a u-joint at the bottom of the steering column.

I suppose one could use a transverse rack with a bell crank, though that introduces more opportunities for lost motion. It could work if one keeps the arm lengths generous and gives a bit of attention to the joints and bearings.

 

By the same token you could run a vertical rack, with a bell crank at its bottom end ...

 

I think Ak Miller might have had a hand in that.

 

i would like to disagre with x38 on the camira rack set up on a beam i have driven two roadsters with this setup and they are the best steering rods i have been in

 

But they are still inappropriate on a traditional car.

 

But how is it done? Back of the axle?

I'm not sure if I like the back-of-the-axle approach. It might work fine, but it feels a bit like a shortcut to me.

X38, do you think there could be something like Phantom Trad? and if so, what would it take to do it? Could one somehow give a fore-and-aft R&P, for instance, the feel of a '50's aftermarket component?

 

In this case, it bolts to the frame, the tie rods pivot from the centre. I'm doing some work on a car with the setup on Wednesday, I'll try to remember to take some pix.

Please don't make up words like phantom trad! We have enough trouble with rat rod!

 

Yes, I can see it running away!

 

If you find a rear mounted rack of an apropriate width, and position it off, (and mount it to) the axle correctly for the geometry to function well, you'd be pleased w/the performance. Carefully consider loads, fatigue strength/mounts and stress concentrations (sharp corners/edges).
Provide enough material to keep mount stress "low", it is going to bounce up and down w/the axle. Completing a second car I've done in this manner, and I've used European racks that include the VW Rabbit.

 

Gregg in Azirona needs to get out more. You can readily do rack-on-a-beam, and if you pick the right rack there's absolutely no problems whatever. I've had several and wouldn't trade them for cross-steering OR draglink on performance; they're simply flunk the "period correct" test. Manual rack from Dodge Omni works extremely well -- most hotrods are light enough as to not need the power assist -- and they'll mount cleanly behind the axle using Ford ball joints. I even found an excellent, small, manual rack in an "auto recycling facility" that had been manufactured by TRW-Italia but was factory equipment on a Yugo. Worked great on a Model A! PM me and I'll send details.