Rack and Pinion: Should I start over?

I've been trying to set-up the steering if my '54 Hudson Jet, but I think I'm in over my head! Obviously didn't do enough research before hand, and look like I'm going to learn this lesson the hard way (we've all been there right??)

The original Hudson Jet steering is long gone, and the homemade crossover steering in there before was really scary, so I decided to try and mount a rack and pinion in my car (it's out of a late 90's Chevy Lumina or Monte Carlo).

Just curious if this set-up will work at all, or if I should just start over from scratch....











Any help is greatly appreciated!

 

I'm no expert but I can see from the pics you need to move the rack forward so the tie rods are straight. The lower "A" arms should be parallel to the ground at ride height. You may need to heat and bend the steering arms to get it all lined up but I think it will work.

 

Thanks for the advice- I forgot to mention that the car is rear-steer... I'm guessing you mean space it out further from the crossmember to line everything up?

 

I'm pretty sure that's what he meant. It should line up so the tie rods are more straight across. However, even with the shortest tie rods that work with that rack, I think it will be too wide for that application.

It may be time for a MII.

*Edit: Jem and need louvers? are right about the Ackerman.

 

Okay, I can't tell quite enough from your pics to know for sure, but relative to how something like that should REALLY fit, I'm a tad concerned.

First off, go put the rack and the wheels straight ahead. Then hang something from the inner control arm pivot so you get a projection of the pivot axis to the rear of the arm. Get the vehicle sitting on its wheels at normal ride height (on a lift, or sitting on blocks under the wheels so you can work under it) - it's the 2" of jounce/rebound from normal ride height that really matter in terms of steering geometry.

Then stick a tie-rod end in the steering arm and SWAG a horizontal (left-right) distance measurement from the tie-rod pivot center to the lower control arm outer pivot.

Then go measure that same offset distance, in the same direction, from the inner control arm pivot axis. If your rack inner tie-rod end doesn't pivot within 1/2in or so +/- that point (ideally closer, but in the real world we take what we get) you're gonna have bumpsteer problems. If the rack is too long, or a lot too short, throw it away and find something shorter/longer as appropriate. If the rack is a little too short you might be able to make/buy something to space the inner tie rod ends out a bit.

That's the horizontal, now the vertical. Same thing. Once you have a rack that's the right width, measure the vertical distance from LCA outer pivot to the tie-rod end at the steering arm, it should be the same vertical offset from the LCA inner pivot axis to the tie-rod inner pivot on the rack. If it's not raise/lower the rack to get it there.

That's the basics, then we get into moving the rack forward/backward to get the ackermann angles right.

Let us know what you come up with.

 

check out this mid size Gm rack swap. you could move the pivot points to match where they were on your stock suspension to advoid bump steer

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

 

Jem is on the right track, and just by the pictures that you have I can tell that the way you are set up will be bump steer deluxe. To expand a bit on what Jem was saying, the inner pivots of your rack should end up somewhere on an imaginary line drawn from the upper control arm's inner pivots, and the lower control arm's inner pivots. Operating those rack inner pivots out side of those parameters is going to end up with rapid toe in/out change as the suspension moves though it extremes. And, yes, as Jem stated, the rack's fore to aft placement is often used to control Ackerman, so it doesn't necessarily have to be straight across...

 

ya, you got a mess happening. no insult intended, please. the rack timothale...pointed out may work for you much better. oh and contrary to belief, tierod parallel to ground has no bearing.....parallel to lower arm ,yes. have built many custom IFS. Used the center steer gm rack with pretty good success. Aim for zero bump steer, but even Detroit cars don't always have zero bump. but warning...1/8" over 2 " of travel , well may get a little exciting behind the wheel. good luck ,but get away from the rack you are using , definetly use a shorter pivot to pivot. the center steer , bout your best starting point in this application. feel free to call the shop if you need more help. good luck

 

I believe your Hudson originally steered from a central pivot where both tie rods joined a central sector type arrangement. One solution may look like this:

This type of rack was used on Dodge Intrepids and Chevy Cavaliers a**** others.
Here's some more reading:
http://www.jalopyjournal.com/forum/showthread.php?t=627197

 

Thanks for the help guys- I will look into everything soon, and report back.

The Hudson did steer from a center pivot point- I made my mount to bolt up to the stock location on the crossmember.

I've seen some threads on shortening the rack itself- would that be an option for me, or should I think about a completely different rack?

I did find a couple pictures of a Jet with a rack and pinion installed... A little bit more modified then mine, with disc brakes and S-10 spindles. The guy stated that he used a rack and pinion out of a 2000 Cavalier.

 

This could actually be dramatically improved by making a plate that bolt to the current inner tie rod end holes and would be drilled and tapered to accept them out further. Basically, you want the tie rod inner pivots to line up on the lower control arm inner pivots - PROVIDED the rack was mounted on the same plain as the lower control arms. As the rack was moved higher in the frame, those inner rack pivots would have to get wider.

 

Fatman sells a rear steer Cavalier set up I believe it was for a shoebox, however I have modified it to work on on other cars. Also the Jag XJ6 is a nice easy job on your car. The whole front subframe goes under your car and you can notch your frame should you need the front lower.....you have Chevy bolt pattern on the wheels. There is a whole bunch of info on this swap in this site.

 

The Cavalier rack is what I used on on my 54 Chevy. Found a how too thanks to google and can't be happier with the results. Drives great with no bump steer.

 

No need for me to say anything other than, exactly.

 

Couldn't agree more.
I grabbed that pic from a Google image search because it looked a lot like the Hudson with the angled control arm pivots and tie rods close to where the center pivot for the Hudson's steering sector originally was.
It seems like many factory setups could be improved upon by some modern hot rodders.

 

Those control arms and those tie-rods are long enough that the relative difference in length will be somewhat less important than they would be if everything were shorter, suspension motion creates less angular change.

Obviously, better is better, but at some point and for most purposes good enough is good enough too. I bet that one works really well.

That looks like a GM J-car rack, which I think has been discussed on the board before, a whole swath of '81-mid '00s Cavalier-derived smallish GM hardware as well as '94-03 Saab 900/9-3 (the '94-95 used a ZF rack of similar configuration, '96-up was a Delphi rack similar but not quite identical to the US Cavalier piece...)

Where some J-car installations fall down is that the rack doesn't have a lot of lateral travel, so if your steering arms are longer than the J-car's fairly short arms you end up with a 45ft turning circle.

 

Looks like the J-Car/Cavalier rack and pinion may be the way to go... Perhaps I can even salvage part of the mount I made for this rack.

Live and learn right?

 

Looking at this picture, I think it's the same rack that I have. It looks like the guy built a bracket going from one end to the other, and then mounted the tie rods in the middle. Does that achieve the same thing as the older Cavalier center-mount style?

 

I was doing some more searching and found another version like the above picture... Maybe a bar across, and bolts into the sockets would solve my problems and give me center pivot.

 

some NASCAR Mod guys use a set up like that......

 

Wow.
That connecting bar thingie looks like it has some kind of guide bracket to keep it from rotating but it sure isn't an elegant solution to your problem and may be more headache than it's worth. You can adapt anything to work but at what cost in both money and safety?

I see in your build thread that you have the old steering sector. Reinstall it and get all the measurements so you know where to locate your inner tie rod ends in the factory positions. It would be good to know how far it moved left and right too.

Whatever rack or method you choose should mimic the factory tie rod positions and movements as close as possible if you are keeping the rest of the factory suspension. Also keep in mind the routing of your steering shaft with the fewest universal joints and least amount of angle changes.

 

I do have the original sector, but the arm that actually came out and pivoted for the tie rods was lobbed off with a torch long ago- it might be a little hard to measure off of that. I just happened to see that other rack and pinion and figured I'd throw it out there- heck Flaming River is charging over $2,000 for that rack!

 

Not sure if it mentions it in the link, but...Cavaliers are rear steer while Intrepids are front steer. They will not interchange in that you can't simply replace one with the other as the car will turn left when you steer right!

 

Ooops!
I was only thinking of the center connecting point for the tie rods there and didn't mean to imply they were interchangeable. Thanks for pointing that out.
The Intrepid front steer rack should work fine on any front steer project that needed the inner tie rods closer together like an s10 based project and Cavaliers for rear steers.

 

Just wanted to make sure that anyone reading it would realize the difference because it would be really easy to ***ume the Intrepid is rear steer as well, considering the rack is mounted to the firewall! Odd setup....

 

Jem I am in the same process with my 1941 Chrysler and when I think I have it figured out ,I read more info and I usually become lost .Is there any way that the instructions you have stated could be explained with a diagram.It would be so helpful. Thanks Gary

 

Hey Nukeman, Did you use the original the original Tierod setup ? Also how thick is the material for the bracket that connects the tie rods to the rack.

This setup looks beefier than the using the tie rod adapter that comes in the Plydo kit. I had it snap in half while driving !

 

And for another headache, make sure the pump puts out the pressure (usually stamped on pump) that the rack is looking for.

 

The tie rod pivots need to be on the correct intersecting plane between top and lowers pivots when viewed from above and from front/rear to avoid bump steer. Here's a rough guide as to where they need to be to maintain correct geometry. A friend did this conversion on his 467 Olds convertible and used 7/16" solid bar. When using OEM steerng arms, Ackerman is maintained but you need to check lock to lock.

 

Good stuff. I want to do a narrowed mustang II rack in my O/T ride later this year, lots of good info here.