Conversion Question

-
dustadude

dustadude

Well-Known Member
Joined
Jan 30, 2014
Messages
236
Reaction score
29
Location
San Lorenzo, Ca (SF East)
Has anyone on here ever tried converting their giant power steering box into a rack and pinion unit say out of another Mopar? I was wandering around the junk yard today and looking at a late 90's ram with rack and pinion and wondered if that was something that would work?
 
Many many lengthy threads on this. Short answer is "I know of no way" other than

CAREFULLY re-engineering a rack in the same relative spot as the original center link. I have seen none that appealed. Usually, a radical steering shaft angle results

Problem with front mounting, is the design of the original spindles screw up steering geometryl

Otherwise, is to build your own / buy one of the aftermarket 'Stang front ends which properly puts the rack "up front"
 
67Dart273 said:
......Uh, whut? The problem IS the spindles
Click to expand...

I agree.....Modifying the factory rear steer spindles is nothing new. I did it in the early 90s because I saw it done on early Pro Stock cars ( early 70s) that have very limited suspension travel ( bunp steer issues) and mostly are only concerned with going straight (ackerman issues).

But to the original question......just consider having to design the pivot points for numerous salvage yard racks (regardless of price) OR design for a common unit that are readily available and you can buy NEW for around $200- $250.

It can be done.....just not cost effective.
 
blown71duster said:
The problem is guys try to use the factory steering arm/ball joint and turn it to the front which screws up the geometry.

Magnum force uses a bolt on steering arm custom made for front steer to use the stock spindle, Bob's performance uses something similar:

http://www.bobsprofab.com/
Click to expand...

Oh crap, LOL, now I see the error in my thinking. For some reason I was picturing factory spindles AND ball joints / steering arms.
 
Placing a steering rack to the rear of the K thus keeping the rear steer and geometery looks simple at a glance. 2 issues result, as Del said, getting a steering column shaft attached will be difficult, then getting exhaust past the rack without cooking it.
The later model rear dump Magnum manifolds may be the way but those have cooked floors and feet in a few cases so.... aftermarket front steer seems to be the best route for those who really want R&P steering in a-body
 
The Borgenson box, which seemed to get off to a somewhat rocky start, has gained ground as a cheaper way to get responsive steering. Frankly, for my own part, I don't HAVE another 4K or whatever to spend on "improved" front/ rear suspension.
 
While I have not really looked into it there is a rack that may work in most situations. That is from the LH cars. This is something that apparently is starting to get some attention from Mustang folks (my son is building a '65 for his wife). Since that rack steers from the middle, length is not an issue. I would build semi-custom tie rods with heim joints on the inner end, though.
 
what if you used a rack from a car that used rear steer spindles?
 
dukeboy_318 said:
what if you used a rack from a car that used rear steer spindles?
Click to expand...

The problem that you run into is finding a rack and pinion that has enough travel to have a decent turning radius and bump steer issues with the stock K-frame:

http://www.crankshaftcoalition.com/wiki/Swapping_to_rack_and_pinion_steering


The muscle cars that came with steering gearboxes have a lot more travel than a rack and pinion gear can usually provide.
The length of the steering arm from the center of the ball joint to the center of the tie rod end dictates on how much the steering gearbox or rack need to travel .
On a mopar it' s like 7 or 7.5 inches , which means your rack and pinion needs to be able to have that much travel to get a full turn.
I have driven a car with a rack installed that you could not pull into a parking space without backing up and turning again to get parked.
Also when it hit a dip in the road the bump steer was bad enough it would move the steering wheel.
It can be done, but not what I would want to drive.
Probably better off with the quick ratio Borgeson box on a budget.
Unless you could use a custom rack that had adjustments and travel like this:

[ame="https://www.youtube.com/watch?v=OwT5ruol4yU"]Universal Steering System - Jay Leno's Garage - YouTube[/ame]

Last time I checked it's price was outrageous.
 
Jim Lusk said:
While I have not really looked into it there is a rack that may work in most situations. That is from the LH cars. .
Click to expand...

Those have more travel than most, but they are for front steer applications . The center bushing design had a bad reputation on those .
 

Attachments

  • front-suspension.jpg
    43.4 KB · Views: 248
blown71duster said:
Those have more travel than most, but they are for front steer applications . The center bushing design had a bad reputation on those .
Click to expand...

Yes, the center bushing was pile of dog poo, which is why I would build custom tie rods with a heim joint on the inside. It's been a long time since I owned an LH car, but I thought they were rear steer (I'd have to check my manuals).
 
Those were just a strange setup with the north/south engines . You would think its a rear steer with the rack mounted at the firewall, but the steering arms on the struts are on the front .
Too bad they would have made a good junkyard swap rack.
 
blown71duster said:
Those were just a strange setup with the north/south engines . You would think its a rear steer with the rack mounted at the firewall, but the steering arms on the struts are on the front .
Too bad they would have made a good junkyard swap rack.
Click to expand...

Ok.....then how about a Eclipse rack? I had a 05 Eclipse, had to replace the rack, they were rear steer spindles and their rack was mounted on a crossmember just infront of the firewall?

If it did work though, you'd more than likely have to mount it low under the rear of the engine and somehow get headers to clear....
 
Most racks have less than 6 inches of travel , which would create a severe lack of turning radius. And getting a rack built for another car to fit these older chassis and not create bump steer is two problems very hard to overcome.
Unisteer came out with a rack and pinion conversion for B-bodies , they even had issues with a lack of turning radius with those.
 
blown71duster said:
Most racks have less than 6 inches of travel , which would create a severe lack of turning radius. And getting a rack built for another car to fit these older chassis and not create bump steer is two problems very hard to overcome.
Unisteer came out with a rack and pinion conversion for B-bodies , they even had issues with a lack of turning radius with those.
Click to expand...

Makes sense. I figured there was a valid reason for it being that no one else had came up with a working solution
 
blown71duster said:
Those have more travel than most, but they are for front steer applications . The center bushing design had a bad reputation on those .
Click to expand...

Hmmmmm......that just re-lit the light bulb on something I tried years ago.

Maybe time to take another stab at it
 
You must log in or register to reply here.
-

Back
Top