[Columbus]

Deep thinking... Trying to understanding what type of rack needs with correct fitment...
I do not have service to measure all, but do as possible...

Crysler 300M (total width 880mm):

Probably side mounts are here on caprice frame where two red rectangles:

 

[Blue Bowtie]

That rack unit is not from an Astro/Safari van. Or at least not from what was sold in North America badged as an Astro/Safari (GM Truck/Bus Division designation M-Body).

This is the steering gear used on 1985-2005 Astros:

 

[Columbus]

Virtualy mounted 300m rack and pinon😁
That is the end of project 😁

Doubts about the location of this part, it is from below!

 

[Columbus]

Maybe anybody can make 3d scan of caprice/impala 91-93 all front stuff?

 

[SSandman]

Just wanted to say I love this thread. Haven't had a chance to read it all yet but I feel like a steering rack would be one of the most beneficial things one could do on these cars if done correctly. I'm running a turn 1 steering box on my build, and I have zero complaints. It FEELS like most cars i've driven with rack and pinion but the thing I love about rack and pinion is that it uses fewer linkage parts which is huge on a car this big, heavy with wide front tires. We all know how fast these cars eat through linkage parts and even when new how much flex could be in them. Fairly sure rack and pinion on these cars would create a huge improvement in steering feel.

Wish I took the time to try to make something on my build but just had too much other stuff going on with it.

 

[Marky Dissod]

... a steering rack-&-pinion would be one of the most beneficial things one could do on these cars
if done correctly.

To my memory of several ISSF threads prior to Aug 2009, the geometry from the steering column to the rack would determine whether or not it was a resume enhancement, or a bona fide performance improvement.

 

[95wagon]

"fewer linkage parts"
Yeah , take a look at the stuff they are hanging on these transplanted racks to get an inner pivot in the right place and keep it from rolling.

 

[Columbus]

Just wanted to say I love this thread. Haven't had a chance to read it all yet but I feel like a steering rack would be one of the most beneficial things one could do on these cars if done correctly. I'm running a turn 1 steering box on my build, and I have zero complaints. It FEELS like most cars i've driven with rack and pinion but the thing I love about rack and pinion is that it uses fewer linkage parts which is huge on a car this big, heavy with wide front tires. We all know how fast these cars eat through linkage parts and even when new how much flex could be in them. Fairly sure rack and pinion on these cars create a huge improvement in steering feel.

Wish I took the time to try to make something on my build but just had too much other stuff going on with it.

3D scanning will help.
Know who can scan but he need payment.
I do not promise the installation of rack and the final result, but we can try for 30 years.
May be donation from forum is possible?

 

[Columbus]

3D model online:

Chassis Chevrolet Caprice (1986) 3D CAD Model - 3D CAD Browser

Download Chassis Chevrolet Caprice (1986) 3D CAD Model for AutoCAD, SolidWorks, Inventor, Pro/Engineer, CATIA, 3ds Max, Maya, Cinema 4D, Lightwave, Softimage, Blender and other CAD and 3D modeling software.

www.3dcadbrowser.com

 

[Columbus]

Found bmw e30 rack from e30 club for free, wait for shipment.
Another interesting rack is from nissan teana j31 right hand driving.

 

[Columbus]

For a first lookup the place for rack and moving brace like astro must me here:

The rack housing will partially affect the center link, which is already wrong. and given that a bracket is needed, it is more logical to position the steering rack as in the figure.

The r&p outter tube diameter is about 50mm for bmw e30.

 

[Columbus]

 

[95wagon]

View attachment 207311

And I bet someone is very proud of that.

What I see is inner pivots a mile from the centerline of the rack .
Any large forces on the linkage when ever the tie rod is not in perfect line ( only would happen at one point in travel) will try to move the tie rod up or down creating a twisting force on the rack shaft. This binding the gear, wearing things out or loosening that entire carriage they made.
Sure they strapped on a little pair of guide rollers to a bracket that is pinch clamped to the rack housing but how long before it shifts or crap gets jammed between the rollers and carrage.

The above is my opinion , feel free to disagree.
If you are trying to do this whole deal to prove a point, great.
If you are trying to build a marketable kit, I feel you are going to find no market.

 

[Blue Bowtie]

Agreed. A recirculating ball and sector gear is virtually bullet-proof as long as it is lubricated. No one, almost EVER, replaced a Saginaw steering box unless they wanted to go to a variable ratio (F-Body) or the box was damaged in an accident or from running it out of oil. Steering racks are replaced almost as much as ball joints due to wear, and the resultant leakage. That should define the potential demand.

 

[Columbus]

Found me known guy with 3d scanner and ready to scan front area!

 

[Columbus]

Agreed. A recirculating ball and sector gear is virtually bullet-proof as long as it is lubricated. No one, almost EVER, replaced a Saginaw steering box unless they wanted to go to a variable ratio (F-Body) or the box was damaged in an accident or from running it out of oil. Steering racks are replaced almost as much as ball joints due to wear, and the resultant leakage. That should define the potential demand.

Agreed.

 

[Columbus]

The mounts must be like tahoe 900 or same way...
Flat mounts and fluid flares are on top of tube.

 

[Columbus]

Here are the first source for me how the r&p must mounted!
There interesting moments where found info how to and where mounts must be placed. This is the only correct option(variant) for the location of the mounts and mount bar for the steering rack. That is why gmt 900 r&p interested me.

 

[Columbus]

One bolt mount ???!!!!

 

[Columbus]

This is 3D low quality front part of frame... with unknown dimensions.

frame - Google Drive

drive.google.com

Maybe if i coud have a more compute possibilities(cpu about 88 + gpu ), this 3d mesh will be more precision, but 4 core xeon (8 threads) and gtx 960 4gb with ~1000cuda make this 7 days..