Rack and Pinion Adventure

[mechanixman]

Hey Everyone
I figured if I go through the steering like I did the brakes, I might as well post it too. So it started off with steering box woes. I couldn't fit anything that had a drag link like the original steering set up. I looked into a cross steer set up, but both the steering shaft and figuring out the exhaust would still be a nightmare. So I decided a rack and pinion was the way to go. A lot of the people talking down about this set up had the same responses, each of which I'd like to address.

The Bump steer will be out of this world!
I'm not mounting my rack and pinion to the frame, but to the axle. And in turn, eliminating any bump steer whatsoever.
Side Note: Technically, if you mount the rack in the right place, the wheels will move in and out the same amount, meaning bump steer really won't be much of a problem. But because you're measurements have to be so exact for that, I'f prefer not to.

You're adding unsprung weight to the vehicle, meaning your handling and performance will go down.
2 things to that remark, both come from the president of No Limit Engineering.
1. His kit only adds 3.5lbs to the axle. The one I'm building will probably add 6 lbs. That's hardly anything at all! especially considering you're adding at least 10lbs to the wheels just by doing a brake disc conversion.
2. Since when does "classic truck straight axle", and "performance and handling" ever go in the same sentence? I'm not racing this at Bonneville, I'm using this as a daily driver! Somewhere I won't really need to worry about handling performance any more than usual. Maybe it would be a problem if I had a drilled out axle with carbon fiber components on it, but that is not the case.

Now the final (and my biggest concern)
Now if you mount it to the axle, you need to have a steering shaft with a slip joint in it. They tend to be high maintenance, and it could fail.
Now this is a concern of mine, but the reason I have disregarded this is because flaming river makes a couple dozen telescoping steering shafts for several makes and models, all look well built. The No Limit Engineering kit uses it, and classic trucks magazine used the no limit engineering kit in their AD pick up. If these steering shafts did fail as frequently as some people say they do, I feel like at least 2 companies wouldn't be selling them, and a national magazine wouldn't post an article involving one.
If anyone believes what I have said is wrong, please let me know. I'd much rather be wrong than in a hospital bed.


Phew! Now that being said. Here's what I have started on this project.
The original tie rod measures 48" center to center.
I picked a mustang II rack because it measures 45" to the ends of each rod.
I bought the K member out of an 87 mustang for $50.

The original tie rod ends are $110 at any local auto parts store, and it's hard as hell to find a 1/2-20 tap to make any kind of adapter. So I decided to find myself a modern, cheaper equivalent.
I spent an hour and half at oreilly's two days ago finding a set of tie rod ends that actually would fit the original steering arms.
Here it is! it's a little bit larger, but it will work perfectly. This came out of the for Aerostar! (I never thought I'd use any part from one of those van on this truck.) $15 for the tie rod end! Part number at oreilly's is es2262rl
I figure if anyone wants to update their tie rod, this is a good start.

Right now, I need to work on making a bracket to securely hold the rack to the axle, and an adapter to mount the 9/16-18 mustang tie rod to the M14X1.5 tie rod end from the aerostar.
We'll see what happens!

[dwcsr]

run a 9/16-18 tap in to the 14 mm. 18 tpi and 1.5mm are almost identical

[Lextech]

I am not familiar with the slip type steering shaft from Flaming River. Are these made for constant in/out slip and are they sealed and greased? I am thinking that you need a small diameter slip joint similar in function to a driveshaft slip joint that is made to constantly move in/out. It will also need a good bit of travel. You wouldn't want to hit a big pothole or driveway dip and disengage the splines of the slip joint.

Jeff

[mechanixman]

Originally Posted by dwcsr

run a 9/16-18 tap in to the 14 mm. 18 tpi and 1.5mm are almost identical

Thanks for the tip!
That will make life so much easier.

Originally Posted by Lextech

I am not familiar with the slip type steering shaft from Flaming River. Are these made for constant in/out slip and are they sealed and greased?
Jeff

Here are a couple links to one of the pages of them:
https://www.flamingriver.com/index.p...ts/c0008/s0001
https://www.flamingriver.com/index.p...ipshaft/FR1856

Yes they're made just like a driveshaft's joint. They're sealed and even have the rubber boot.
The travel is 3" which isn't bad, but I'd like it to be a little more. I think that will be enough for everyday driving, but what concerns me is when some one lifts up the truck by the frame instead of the axle, and the shaft can't stretch that far.

[Lextech]

Maybe check with your local driveshaft shop and see it they have something with a longer slip stroke.

Jeff

[62ChevyII]

I am on board with the idea of mounting the rack to the axle and I am not too worried about a slip joint wearing out but one question I have about your rack choice is this: do you plan to make this a front steer arrangement? The MII rack is a front steer rack. If you mount it behind the axle like AD trucks steering arms are I think the wheels will turn left when your turn the wheel right...

I have started looking into rear steer racks and I have seen people use Dodge Omni/Plymouth Horizon racks for rear steer applications. I was thinking a guy might be able to find a whole power rack and pump and lines out of a salvage for pretty cheap and adapt them to the Chevy truck.

Maybe I am missing something about your plans but just thought I would ask. I am looking at doing the same thing myself on a 51 and I ain't buying a high dollar kit if I can keep from it.

[mechanixman]

Originally Posted by Lextech

Maybe check with your local driveshaft shop and see it they have something with a longer slip stroke.

Jeff I like that idea. I'll give him a call monday, and see what we can come up with.

Originally Posted by 62ChevyII

If you mount it behind the axle like AD trucks steering arms are I think the wheels will turn left when your turn the wheel right...

That would be pretty interesting!
But it does work with a rear steer application.

Originally Posted by 62ChevyII

I have started looking into rear steer racks and I have seen people use Dodge Omni/Plymouth Horizon racks for rear steer applications. I was thinking a guy might be able to find a whole power rack and pump and lines out of a salvage for pretty cheap and adapt them to the Chevy truck.

Actually, I bought my 305 with a power steering pump on it, and from what I've read two little adapters let you run the pump and the rack together. So I'll I'm missing are the lines and adapters.

Originally Posted by 62ChevyII

Maybe I am missing something about your plans but just thought I would ask. I am looking at doing the same thing myself on a 51

Thank you for the questions. It never hurts to double check. I thought I read you were planning on doing the same thing. I like you're way of thinking!

Originally Posted by 62ChevyII

I ain't buying a high dollar kit if I can keep from it.

I like the way you think!

[62ChevyII]

Originally Posted by mechanixman

That would be pretty interesting!
But it does work with a rear steer application.

I am curious how this will work. A front steer rack moves right when you turn right but a rear steer rack moves left when you turn right because the steering arms have to move left in the back to turn right.

What do you do mount it upside down or something to get it to work?

[mechanixman]

Aww man
It took me a few minutes of just trying to work out how the steering was going to work.
You are correct, it is a front steer and it won't work like i originally intended.
Does anyone have reasons to not go with a front steer set up? aside from the awkward steering shaft position.

[Russell Ashley]

It might be a little difficult to get the ackerman right. You might have better luck by finding a rear mounted rack. GM compacts from the eighties like Pontiac Grand Am's and similar had rear mounted racks and should be plentiful at pick and pull.

[62ChevyII]

Originally Posted by mechanixman

Aww man
It took me a few minutes of just trying to work out how the steering was going to work.
You are correct, it is a front steer and it won't work like i originally intended.
Does anyone have reasons to not go with a front steer set up? aside from the awkward steering shaft position.

Imagine your surprise if you fabbed that all up and the wheels turned the opposite direction.

Originally Posted by Russell Ashley

It might be a little difficult to get the ackerman right. You might have better luck by finding a rear mounted rack. GM compacts from the eighties like Pontiac Grand Am's and similar had rear mounted racks and should be plentiful at pick and pull.

Thanks for the info on the Grand Am rack... I bet the GM rack will work with a GM pump better too. I have heard the MII deal is kinda flakey with a GM rack even with the adapter stuff they make for it. Should be lots more in the salvage yard than the Omni/Horizon units too.

[47 Fasttoys]

FWIT, I'm not sure who makes it but there is a gear unit which reverses the shaft output. I saw one of these on an old hot rod. Basically it's 2 gears with spline shafts coming out of opposite ends. Using only 2 gears it reverses the rotation. Think of a clear steer unit with only 2 gears. I would think you would need at lease 5 inches of travel for the solid axle. 1 good pot hole and compression and your at 5 inches.
Good luck,
Rob

[Old Crow]

A few years back we had a guy bring a truck in that he had fabbed his own r&p setup. Had done the reversed rack deal and it did indeed steer backwards.
Worst part of the whole thing is he'd moved it around enough to be comfortable driving it on the road to bring it into the shop. Good thing we're out in the country and not right downtown.

[mechanixman]

Oh my goodness really? That's hilarious (and slightly awful).
Thanks Russell and 67fast toys for the suggestions.

[55dude]

why not use a pre 1986 toyota 4x4 steering box? thats what those overpriced kits from CPP use.

[mr48chev]

Originally Posted by 55dude

why not use a pre 1986 toyota 4x4 steering box? thats what those overpriced kits from CPP use.

That would be a lot better than hanging a rack and pinion on the axle and adding another 20 lbs.

OBTW, Most front wheel drive GM cars have a rear steer rack and pinion and it shouldn't be too hard to find one the right width.

[mechanixman]

I'm sorry i didn't realize I hadn't replied.
The reason not is because I don't have the room.
If I were to fit a steering box without notching the frame, I'd have to mount a vega box in front of the engine. I could almost make it work too, except the tie rod connecting the pitman arm to the wheel would rub against the springs.
We were ready to just buy the kit from No Limit, but one look at the brackets holding the rack to the axle and I knew I had to go through with making my own.
I did just find the perfect rack and pinion though.
The part number from Oreilly's is Part # 22-184 Line: A1
It's a rear steer with the same M14 threading as the tie rod ends for the aerostar. From the end of each tie rod it measures 45". Only modification is to cut each tie rod down so with the tie rod ends bolted on it will measure the needed 48"