[gatz271]

I know this has been discussed before, but my question is; what was GM's thinking on this type of steering system?
All the threads I've read on this topic concur that when adapting a non-stock R&P unit to an older vehicle, the ball-ends must be in line with the LCA shaft pivots.

However, because the tie rods are quite lengthy (compared to having the tie rod ball-ends in line with said pivots); did they figure that any "bump-steer" to be negligible?

The application would be for a 48 DeSoto and my concern is of course, "bump-steer". Can one assume the CTO could work without mods?

 

[d.b. cooper]

i don't have my cavalier in front of me at the moment, but based on memory (and my super-uneducated guess) is that since that rack is so high up, that part of the McPhearson strut does not travel (or travel much) and thus getting the ball-ends to line up with the connection points wasn't a concern?

 

[gatz271]

I was not familiar with the Cavalier McPherson strut system..
Answers my question, thanks

 

[d.b. cooper]

Don't quote me on that. i will try to either take a picture of the setup or find a picture of the setup online. What year rack are we talking about?

In the meantime, here might be some important info:

Swapping to rack and pinion steering

www.crankshaftcoalition.com

i think the consensus is, IF the tie rods are LONGER than the control arms, you'll be ok?

 

[gatz271]

The Cavalier R&P is from a '98 Z24 (quicker ratio ?)
Thanks for the info and link.
It appears that Cobalt,et al might have been able to use the Cav R&P as is, but decided to add the angled bracket for 2 reasons;
1) the R&P was rotated up to align with the steering column
2) spread out to align with the LCA pivot & shifted the tie-rod mounting bolts as the R&P was offset in the vehicle

It's unclear to me how to message someone on this forum.
It says to click on the Discussion tab....but then what ?

 

[S10xGN]

Click on the person's avatar, then click on message...

Russ

 

[Racer-X-]

The application would be for a 48 DeSoto and my concern is of course, "bump-steer". Can one assume the CTO could work without mods?

I have one in a 1947 DeSoto. Are you using a mounting kit for it? And what kit is it? What will you use for outer tie rod ends.

We had a failure in the "tie rod coupler" on a kit that was in ours. I ended up paying a machine shop to fabricate some adjustable couplers with male threads to match the inner tie rods on the Cavalier rack and female threads on the outer, to match the stock outer tie rod ends (aftermarket replacements are still available). Our kit originally used Ford Explorer ends which are female threaded with small threads and inadequate. Also the Exploder taper doesn't match the DeSoto steering arm at all. You can sort of tighten the hell out of it and it will kind of work, but I wouldn't rely on "sort of works" for steering components.

Here's how the Ford Exploder tie rod "sort of fits":

You can see that the castles on the nut don't engage the cotter pin at all. The center taper is too long on the Ford part.

Here's the broken pieces, the original unbroken ones from the driver's side, and the new pieces we had made, shown with a "stock" outer tie rod end.

Our rack was already mounted too high on the car, which was causing the outer tie rod on the right side to bind, which probably contributed to the failure we had. I ended up fabricating a plate in the same position as the one in the post above, but with the left side inner tie rod mounted in the stock position and the right side one mounted a couple inches lower. If we could've mounted the rack lower, I would've made a plate that moved the left up about an inch and a quarter and the right down about an inch and a quarter, as that would've been a better design.

I'll try to get a pic of our linkage plate on the rack in the next day or two.

Oh, one more thing, with the Cavalier rack, you've got the turning radius of a battleship. You can fabricate new steering arms for the king pins that are shorter, but there's nothing "on the shelf" anywhere to fix that issue. We haven't spent the money on a fix for that yet. We just deal with the fact that turning around isn't a "3 point turn," it's somewhere between a 7 and 9 point turn.

 

[Racer-X-]

Here's a pic of the plate on our1947 Desoto that lowers the right side tie rod to where the outer tie rod end never binds up or runs out of "tilt" travel on the ball.

 

[brading]

Here is how someone reduced the turning circle when going from Box to Rack steering.

https://jalopyjournal.com/forum/threads/50-plymouth-power-steering-conversion.1069141/

 

[gatz271]

View attachment 628269

Here's a pic of the plate on our1947 Desoto that lowers the right side tie rod to where the outer tie rod end never binds up or runs out of "tilt" travel on the ball.

So, no issues with bump-steer ?

 

[gatz271]

@Racer-X-
Did you modify the tie rods at all ?

 

[Racer-X-]

So, no issues with bump-steer ?

I honestly haven't checked, and since I set the toe correctly, the driver is thrilled with steering and "handling," but this one is mainly used as a wedding limousine for the bride and groom. It's Elvis the "Hot Rod" 1947 DeSoto wedding limo.

@Racer-X-
Did you modify the tie rods at all ?

It came to me with the stock Cavalier inner tie rods, and that "kit" with the adapters to fit the Exploder outer tie rod ends. All I did to fix the big issues was the custom adjusters and "stock" outer tie rod ends, and the plate that lowers the right side. There's still an issue with power steering in this one. I'm not sure if it's the rack or the pump. There's a chance that I might at least check the bump steer situation when I get to that. But bump steer is not an issue for the drivers, so it's not really a priority for me. And the drivers are so happy it goes where it's pointed, and the steering effort isn't very high due to the long arms and minimal movement for the wheel input that I haven't even had complaints about the lack of power assist. I notice it, and it bothers me, but it won't come to the forefront unless/until I correct the steering arm geometry to give it a better turning radius. Even that's not an issue because the drivers are used to driving 30ft or longer "stretch limos", so this thing does just fine in the parking lot by them.

The truth is, this car has been a very big project between jobs, and things like putting the engine in straight and centered in the car, and new rear leaf springs and correcting the pinion angle so the rear u-joint doesn't scrape on the floor pan and replacing the fuel tank and the exhaust system that crushed the fuel tank causing the leak have been higher priority.

The cool thing is, since Elvis (the car) is employed, he makes enough money to afford all the fixes, mods and upgrades.

 

[sbutler]

I put a cto rack from a dodge intrepid on a 1988 S10 frame with a 1939 ford body. Mounted the rack in front of the steering rod and built a bracket to tie it to the S10 steering bar. Kept the steering geometry as stock

 

[gatz271]

Here is how someone reduced the turning circle when going from Box to Rack steering.

https://jalopyjournal.com/forum/threads/50-plymouth-power-steering-conversion.1069141/

Pic from post....

Looks to be that would make it 2 1/4" shorter where the tapered tie rod end fits.

Here's what I did to "shorten" the steering arm; it is half that amount or 1 1/8"
It is also an integral part of adapting Explorer disc brakes to the '40 Chrysler, and to use the Cavalier R&P
I ended up going with something different (after all that work), so this setup will be used for a friend's '48 DeSoto
LEFT side.; stock spindle and steering arm.

exploded view from different angle.....

 

[brading]

That looks like a good idea.

 

[sbutler]

That looks like a good idea.

I'll try to post some pictures, there is a big how-to article on this but not on a s10.