Rack & Pinion on Stock Crossmember?
 

I am looking for a way to mount a rack and pinion to a stock 67 C10 crossmember. I have seen the Flaming River setup, but it looks expensive. How can I make a bracket to bolt a used rack in front of the crossmember, but low enough to miss the pan?
Also, what rack would be long enough to span a truck, have the right threads for the C10 tie rod ends, have the steering shaft in the right spot, and be tough enough to handle getting beat up?
It looks like all the MII racks need studs welded on the front crossmember to mount, and that would be fine, if I could find someone that will sell me a bracket with a stud on it that would weld to the front of my crossmember.
Now thats the type of DIY article I wish the magazines would publish.

Re: Rack & Pinion on Stock Crossmember?
 

I too am interested in this! You can buy new x-members but like you said, they are expensive. Maybe you would have to cut out part of frame? IDK

Re: Rack & Pinion on Stock Crossmember?
 

When you guys get it figured out, be sure to share the results w/the group. What's wrong w/just getting a spec built factory ball & sector style box & using high quality steering parts?

Re: Rack & Pinion on Stock Crossmember?
 

Well, mine is bagged so I would need to somehow mount it above the frame or in it I think.

Re: Rack & Pinion on Stock Crossmember?
 

what advantage does the R&P offers over a stock style steering box?

Re: Rack & Pinion on Stock Crossmember?
 

Typically a more positive road feel and quicker response. Less effort and quicker ratio. Less parts to wear out or create slop. Overall tighter feel. More compact packaging.

The recirulating ball boxes (like stock) worked fine for their entended use but they will not be as good as a R&P setup. If you look almost all auto companies have moved over to R&P setups.

Re: Rack & Pinion on Stock Crossmember?
 

Are you sure that's because of better quality & performance vs. better manufacturing costs?

One of the best aftermarket companies around that does the suspension thing (Detroit Speed; ran by former GM drivetrain engineers no less) utilize OE steering box set-ups vs. a R&P swap. I think a R&P offers better packaging for certain applications for sure, but a recirc-ball box built right w/the correct supporting hardware can work as well.

Re: Rack & Pinion on Stock Crossmember?
 

I am quite familar with DS&E and have eaten dinner with the owners back when I was building my Pro-Touring '69 Camaro. Yes, they do use the stock box setup but when they are working with a stock frame/sub-frame assembly. If you look at their aftermarkt sub-frames (like for the Camaro) they use R&P because it works better for an all out handling vehicle.

Agreed that stock boxes CAN work well and that is what I had on my Camaro (well aftermarket quick ratio stuff) since I was still using the stock sub-frame.

I was REALLY deep into the Pro-Touring scene before my divorce and had to sell my Camaro. When it came to all out handling, most of those guys would spend the bucks to get things switched over to R&P since they were building seriously handling cars. No one who switch every wanted to go back to a stock box/draglink system ever.

YMMV

Re: Rack & Pinion on Stock Crossmember?
 

heres what i found, is a temporary mount but u get the idea.

http://c10forum.com/forum/showthread.php?t=3388&page=9

post 309,327-330

Re: Rack & Pinion on Stock Crossmember?
 

On. The. Nose.

it has very very little to do with handling and everything to do with lower manufacturing & assembly costs (less parts) and more profits for the OEM's. it's called marketing.

I spent quite a lot of time doing work flow, time studies, automation/machining and in process inspection processes for one of the largest producers (TRW) of both recirculating ball boxes and R & P units.

guess which one costs a LOT less to manufacture?

Re: Rack & Pinion on Stock Crossmember?
 

Here is a quick list of the basic parts in the steering system that lead to sloppy steering.
There are a lot of parts in either system. The road feel is controlled by the valve and torsion bar. All power racks use a large diameter torsion bar to provide more “feel”. Most steering boxes can be had with new large diameter torsion bar and have the exact same feel as a rack and pinion. Most center links are curved to fit around the engine and mount the inner pivots in a position to minimize bump steer. All rack and pinions must be made straight, making a less than ideal inner pivot location. The exception is when the upper and lower control arms can be repositioned and changed to minimize bump steer.


Power rack and pinion moving parts:
1 Rack and pinion has an input shaft connected to a torsion bar.
2 The torsion bar is connected to a control valve.
3 The control valve is connected to a pinion gear.
4 The pinion gear meshes with the rack gear.
5 The rack gear is runs back and forth thru the rack housing.
6 The rack housing is mounted on rubber bushings.
7 The end of the rack connects to the inner tie rod pivot.
8 The inner tie rod pivot is connected to the outer tie rod pivot.
9 The outer tie rod pivot connects to the steering knuckle.
10 The steering knuckle is connected to the upper ball joint.
11 The upper ball joint is connected to the upper arm pivots.
12 The steering knuckle is connected to the lower ball joint.
13 The lower ball joint is connected to the lower arm pivots.
14 The steering knuckle is connected to the inner and outer wheel bearings.
15 The inner and outer wheel bearings are connected to a wheel hub/rim.
16 The rim is connected to a rubber tire.


Power steering system moving parts:
1 Steering box has an input shaft connected to a torsion bar.
2 The torsion bar is connected to a control valve.
3 The control valve is connected to a rack gear by a ball screw assembly. (Typically the ball screw is preloaded and has zero backlash.)
4 The rack gear meshes with the sector gear/pitman arm.
5 The rack gear is runs back and forth thru the box housing.
6 The pitman arm connects to the center link.
7 The center link is connected to the idler arm.
8 The end of the center link connects to the inner tie rod pivot.
9 The inner tie rod pivot is connected to the outer tie rod pivot.
10 The outer tie rod pivot connects to the steering knuckle.
11 The steering knuckle is connected to the upper ball joint.
12 The upper ball joint is connected to the upper arm pivots.
13 The steering knuckle is connected to the lower ball joint.
14 The lower ball joint is connected to the lower arm pivots.
15 The steering knuckle is connected to the inner and outer wheel bearings.
16 The inner and outer wheel bearings are connected to a wheel hub/rim.
17 The rim is connected to a rubber tire.

Just a little more info to look at when trying to compare the different steering systems.

Danny Nix
CPP

Re: Rack & Pinion on Stock Crossmember?
 

My point earlier was that DSE uses the recirulating ball boxes on many of their builds w/great success. Their R&P set-up is only available w/their Hydroformed sub-frames.

I equate DSE's front HF sub-frames to an aftermarket frame/part. And they're a high end part @ that (beyond Dropmember territory in 'truck-speak'). If they use the stock/OE sub-frame on a build, they'll use upgraded OE style boxes w/upgraded steering parts as it's not worth retro-fitting a R&P set-up because it won't be optimum.

I feel there's much improvement available just w/the stock stuff w/o the hassle of trying to figure out all the PROPER geometry required to truely benefit from the R&P swap.

Re: Rack & Pinion on Stock Crossmember?
 

Thanks for the info. Sounds like there is a large manufacturing impact here, but what better way to judge performance than to load up 1000 backyard truck builders with a cheap R&P alternative and let them hit the street?
I took a look at http://c10forum.com/forum/showthread.php?t=3388&page=9 and having to notch frame seems extreme. I guess the reason the MII subframes get away with R&P is that the C-arm pivot shaft is a lot shorter? Looks like the stock C-arm has a bump in the stamping in the worst spot to sneak a rack shaft through. Would tubular C-arms have helped here? What about if he had dropped the rack down below the frame, and more forward, like I think Flaming River does?
I think it has to be simple, cheap, and use available parts.

Re: Rack & Pinion on Stock Crossmember?
 

Tubular arms definately would have helped but the frame notch is necessary. With the truck laid out if you draw a line from mounting point to mounting point on the spindles you will see it passes directly through the frame. Both Porterbuilt and Suicide Doors aftermarket cross members use this same method of notching the frame.

Re: Rack & Pinion on Stock Crossmember?
 

This has been one of those "there has to be a cheap and easy way to do it" topics for quite a while.

In short, there isn't a cheap or easy way to slap a rack on the factory crossmember and have an engineered result. You can slap it on and get the truck to go down the road, but if it isn't located in the proper spot it won't be a fun driving experience. Proper location requires a solid understanding/knowledge of suspension and steering geometry, and is best verified with a suspension analyzer software to ensure desired results.

DV8 has done a good job of putting it together on his truck, but I am sure a lot of time/measuring/cutting/welding went into it. And I also know that he has more than an average understanding on suspension geometry.

Re: Rack & Pinion on Stock Crossmember?
 

You definately nailed it with this statement:metal:

Re: Rack & Pinion on Stock Crossmember?
 

Hey,

That reminds me of the old two out of three.

Cheap
Fast
Quality

You can have any two but never three.

Wish someone made a good dropmember for a 1952 Suburban without having the wheel tucked in so far or have to use wheel spacers to get the desired look or track.

Thanks, Dan

Re: Rack & Pinion on Stock Crossmember?
 

It's in the works. :)

Re: Rack & Pinion on Stock Crossmember?
 

Here are some pics from okcminis.com on a square body..

Re: Rack & Pinion on Stock Crossmember?
 

Thats pretty cool, thats basically what im doing with mine. Just been on the back burner here lately..

Re: Rack & Pinion on Stock Crossmember?
 

Okay, the $64 question is.... what rack are they using in that pic above?

Re: Rack & Pinion on Stock Crossmember?
 

looks like a mustang II rack to me.

Re: Rack & Pinion on Stock Crossmember?
 

I didn't think the MII racks were wide enough. The pivot point for the shafts were inboard too far to match up with the control arm rotation.

Re: Rack & Pinion on Stock Crossmember?
 

The guy building the truck says it is a Mustang rack..

Re: Rack & Pinion on Stock Crossmember?
 

Cool. Never thought they would have been wide enough. Good info to know.