OK this has probably been covered before but here goes. I have a 48 Anglia with a straight front axle. It has vega steering and I want to change it to rack and pinion. I bought a Mustang II /Pinto rack and pinion. When I got it I realized it moves the wrong way. I want to mount it behind the axle and it made to mount in front. Price is relevant. I paid $150 new for the Mustang II and would like to stay in that price range. I don't mind buying from a junk yard but don't know what to look for. I'm only interested in retaining the nostagia look of the straight axle with a little better response.
Well you got to take the tires off first. If you don't want to mount it to the axle the best way is to buy one of the racks that are dead on one end and work like a cross steer. I'm sure that someone did it as soon as there was a rack available but the truth of it is that rack and pinion steering is for street rods. Very little to do with traditional rods and customs.
Rack & Pinion on a straight axle cause more problems than they solve. If you mount them to the frame, you will never completely get rid of the bump steer - not even close. If you mount it to the axle, you have to have a flexible shaft between the rack and the steering column as the rack will be moving with the axle and the column is fixed. Yeah some guys have done it over the years, but there is no good reason to do it and only creates problems.
Kind of echoing what Hotroddon just said, if you asked me for this at my shop my first question would be why? Apples for apples, a properly set up steering box and linkage and a properly set up rack and pinion steer with no clear advantage either way. I use either in situations where they can be properly installed, and rack and pinion on a straight axle doesn't fall in those perameters.
I've done five of them and they all work very well. You need a slip joint, but typically it only moves in and out about 1/2". Must be mounted to the axle. It cracks me up when someone says it isn't traditional and then recommends a Unisteer. Works good in my Crosley
My Anglia has about 3.5" of wheel travel and when the front wheels come up it uses it all. I would think that the shaft would have to move pretty close to that same amount. So I'm curious about why yours only moves 1/2", do you not have much wheel travel or am i somehow missing something? Agree about the Unisteers
A lot of water has went over the dam since i last used a rack & pinion. so long ago in fact that the hot setup at that time was a Corvair front suspension with a Colt rack & pinion connected to the steering column by a pinto flex shaft,,,ah,the good old days of junk yard engineering. granted it didn't have a straight axle. And to be perfectly honest that old Model A truck handled like a slot car.HRP
While your axle may travel 3.5" in the "Y" direction, the shaft that connects if at some angle to the horizon and sees only a small percentage of the travel along its center axis. his shaft grows 1/2" in length while the axle travels more.
Same principle as a trans yolk. While the rear axle can move up and down several inches the trans yolk only needs about 3/4" of plunge.
Well, this got me thinking a bit more, so I mapped it out. It depends entirely on the angle of the shaft in relation to the height of the r&p. On a 3.5 " travel, the shaft, if mounted half way between droop and compression would move about 3/8", The higher the angle of the shaft (more likely), the more that movement will be. For instance at a 45 degree angle upward, the movement would become 1 3/4". And this still relies on two universal joints, one at the rack and another on the rack side of the support bearing for the upper shaft (which will need two support bearings). Of course the other option is the good old Pinto flex shaft Personally I don't really like the idea of a slip joint in the steering shaft, but that's just my opinion.
There are other ways to mount racks, though I can't recall seeing any examples. I can think of three, off hand: rack on firewall, bell cranks and vertical shaft to drag link; rack on firewall turned vertical, with bell crank to drag link; rack mounted fore-and-aft to driver's side frame rail, with u-jointed steering column. None of these will produce any more bump steer than any kind of drag-link steering.
ther are going to be the tra****tatorial gestapo who will tell you R&P is not "traditional" but here goes,, R&P has been used in Oval track race cars with straight axles for years,,,as in sprints midgets and supermods, it works well,,just like the guys told you. YOU will have to learn about toe out on turns ( Akerman ),,,cuase how you mount your rack will effect your Ackerman, here is some info No Limit Engineering http://www.nolimit.net/prodinfo.asp?number=PS%2DSA%2D http://www.nolimit.net/prodinfo.asp?number=PS-SA- http://www.rodandcustommagazine.com...steer_products_rack_and_pinion_kit/index.html http://woodwardsteering.com/index.php?option=com_content&view=article&id=682&Itemid=586 http://woodwardsteering.eu/images/basic rack and pinion tech.pdf
If this is to work, the slip needs to be minimized. that's done by reducing the angle. I have a different spin on this, but have never seen it done. how about an axle mounted rack connected to a steer clear drop box with a near horizontal shaft? It would still need a slip joint, but slip would be very small.
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