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Rack and pinion in my ‘48 Plymouth


Scott Knecht

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On 11/20/2021 at 3:56 PM, Scott Knecht said:

Racer X this was the crazy angle I had on my rod ends at ride height with the factory long steering arms.  At full on suspension compression it would exceed the angle limit of the ball joint.  Not sure if you had any of these problems or not or if that contributed to your failure? 

 

I put everything back together yesterday (finally) after getting some custom wheel spacers to replace the wheel shims Bubba installed on it with his "disc brake conversion."  There's a thread about the hubs, bearings, lug studs, etc. here as well.

 

My angles were pretty crazy at full droop (like when the car was on jack stands with the wheels off).  Actually, it exceeded the limits there with the new (stock-ish replacement) tie rod ends.  I couldn't connect the tie rods until I put the car on the ground.  In "normal travel," it looked like the tie rod ends would be in their operating range, but I'm going to have to put a chain on it in place of the shock when I jack it up to take the wheels or do something else to limit droop travel. In the bump direction, our current setup looks good.  It's the droop direction that pushes things to the limit (and a bit beyond).

 

BTW, so far, no response at all from Fat Man Fabrications (I wasn't expecting anything there).

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I ran into the tie rod thing yesterday when putting my new tie rods in.  Turns out I had the inners and outers swapped around.  It was only really noticeable on the drivers side, but then again I have a Plymouth with the long/shot tie rod assembly setup.

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Kind of bummed about the no response from Fat Man.  I thought they would defend their product.  
Like Sniper mine too had the long and short factory tie rods.  As far as the full droop situation, my spindles only moved inward about 2 degrees at the very, very bottom of travel and were perfectly straight the rest of the range all the way to maximum compression.  
By the way I tested my travel without any bump stops installed and I still had over an inch frame to tie rod clearance  at maximum compression. So with bump stops installed top and bottom,  the steering should stay pretty neutral and move bind-free I hope.  All I can say is getting your inner tie rod pivots in line with the A-arm pivots is the key to everything moving as it should.  
As I said before I mounted the rack where I did for header clearance and because I wanted the engine as low and far back as possible.  So fabricating the center tie rod mount allowed me to dial in the pivot points almost dead on.  

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You know, I got to thinking about this tie rod adapter malarkey. 

 

Speedway sells 11/16-18 threaded swaged tubes in a number of lengths.  That is the thread size of the stock tier rod end, which takes care of the outers. 

 

https://www.speedwaymotors.com/Speedway-11-16-Inch-Raw-Tie-Rod-Drag-Link-Tubing,27189.html

 

They sell 11/16-18" rod ends for the inners.  Way stronger and way more safe than that adapter, imo.

 

https://www.speedwaymotors.com/Standard-Steel-LH-Heim-Joint-Rod-Ends-11-16-18-Shank-5-8-Hole,36045.html

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23 hours ago, Sniper said:

You know, I got to thinking about this tie rod adapter malarkey. 

 

Speedway sells 11/16-18 threaded swaged tubes in a number of lengths.  That is the thread size of the stock tier rod end, which takes care of the outers. 

 

https://www.speedwaymotors.com/Speedway-11-16-Inch-Raw-Tie-Rod-Drag-Link-Tubing,27189.html

 

They sell 11/16-18" rod ends for the inners.  Way stronger and way more safe than that adapter, imo.

 

https://www.speedwaymotors.com/Standard-Steel-LH-Heim-Joint-Rod-Ends-11-16-18-Shank-5-8-Hole,36045.html

 

For a stock steering system, I'd go with the speedway stuff for sure.  

 

The issue is when you've fitted a rack and pinion unit.  On these cars, it's apparently fairly common to use the rack from a Chevrolet Cavalier (also used on the other J Body variants, as well as L and N body cars).  That particular steering rack has the inner tie rods attached to it in a way that they don't swivel, and for that particular rack, the outer end of the inner tie rod is female M18x1.5 left hand threads. So you need male M18x1.5 left hand threads on the inner end of your tie rod adjuster piece. The outer end has to mate with whatever outer tie rod end you use.  You need a right hand threaded outer tie rod end, and the rh threaded stock ones are probably the best choice there, but they are 11/16-18 right hand threaded and male.

 

Also, we've got a bind in our steering somewhere that's limiting steering when turning left.  The rack has 3 full turns lock to lock with the tie rods disconnected, and it's pretty well centered on the car.  With everything connected and ready to drive, you can turn the wheel 1½ turns to the right and make a reasonably sharp right turn.  When you turn to the left, the wheel stops turning (binds) at just a little less than one full turn of the steering wheel, and the turning radius for left turns is much wider. I need to do more testing to figure out which side is binding (I suspect the one of the outer tie rod ends  is binding), and I'm going to need to address that soon.

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I think I saw Where Scotty made a plate to move the tie rods up, you can use any type of connection there, be it a rod end with a bushing and not a spherical ball.  You do not need to use the stock cavalier tierod assemblies, but rather replace them in their entirely with your own assemblies.

 

Be interesting to see if your bind is being caused by a tie rod assembly that can't swivel.

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Yes sniper I did.  The stock Cavalier rods use pressed in rubber bushings and sleeves much like a shock absorber mount.  I will not fully tighten them until the car is on the ground at rest.  Then they’ll be in a neutral position.  I would think tightening them in any other position would potentially cause binding.  Yes it would be really easy though to adapt spherical rod ends and I’ve actually given it some thought given what I’m now seeing with the failed FatMan adapter sleeve failure.  

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I’m feeling pressured Bob! Haha

Racer x, Are you sure you have 3 turns lock to lock on your rack? Mine only turns 2-1/2.  If yours is actually 2-1/2 that would explain why you can’t turn fully in one direction.  The rack isn’t centered too start with.  I’m not saying there aren’t racks that turn 3 full turns, I just know mine does not.  

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23 hours ago, Scott Knecht said:

Racer x, Are you sure you have 3 turns lock to lock on your rack? Mine only turns 2-1/2.  If yours is actually 2-1/2 that would explain why you can’t turn fully in one direction.

Yes, I'm sure.  That was checked multiple times when the tie rods were disconnected. The wheel is off, but I put a piece of tape on the exact top. It turns 1-1/2 turns to the right, and the tape is dead center on the bottom when it hits the stop. To the left it turns 1-1/2 turns and again, the tape is dead center on the bottom. That measure was critical when I sourced a replacement that has been sent to an excellent rebuilder for them to go through.

 

When I put it together, I set the toe with the tape straight up and the steering wheel off center.  The tape is straight up so the thing is exactly centered between the stops. All that remains on that is to pull the steering wheel and reinstall it straight.  I've been reluctant to do that for fear the column will fall apart, or I'll discover yet another nest of snakes that will consume more of my time. Every time I look at something new on this car, I find more issues that need to be resolved.

 

I'm home recovering from a surgical procedure on my face (the second one in a week, this one to close up and finish after they removed a basal cell cancer from my cheek last week). So I won't be online much this weekend, and I won't be back to work on Elvis at least until Monday or Tuesday.

 

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Yeah I did some quick research the other day and found some racks do in fact have a 3 turn lock on them. Apparently some models used wider ratio steering.  So something is definitely binding in your case.  One thing I’ve learned with this project is just about every modification leads to another to get everything to work.  Hopefully you can figure it out without too much distress.  
Sorry to hear of the surgery situation.  That’s a drag.  Hope you have a speedy recovery and can resume the project in short order.  

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1 hour ago, Racer-X- said:

. . . All that remains on that is to pull the steering wheel and reinstall it straight. . .

I don't know how they did it on your year/model but on a number of years the spline for the steering wheel is setup so that it only goes on one way. I hope yours works for you.

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I'm not sure what I'll find. The column isn't original.  It's a GM style tilt column with a GM pushrod type ignition switch near the bottom of the column.  And a chrome cover on the column.  It was installed with the custom interior by some shop in Miami.  I'll figure out how to get the steering wheel centered eventually.  I just don't want to touch it yet and end up with ignition switch problems or turn signal switch issues.

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1 hour ago, DonaldSmith said:

Isn't the steering wheel centered by adjusting the tie rods?  The steering wheel only fits on the shaft one way.  

That's correct for a stock steering column. 

 

The one I'm dealing with isn't stock.  There's a lot of non-stock items on ours, and the column (along with basically everything in the interior of the car) is aftermarket "custom" stuff.

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  • 3 months later...
On 2/7/2021 at 11:55 AM, Frank Elder said:

If you can find one I heard Omni racks fit also.

A MOPAR is a MOPAR until  someone sticks a chitrolet into it and then they have a mochit !!!

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  • 2 months later...

Well guys it’s been far longer than I expected to test drive this project but it finally happened yesterday! 
I’m excited to report the rack and pinion and all the mods paid off hugely! 
2-1/2 turns lock to lock effortlessly and factory spec turning radius.  A quick rip down the not-so-smooth road by my house produced zero bump steer!

I’m very happy with things so far.  
Still have much to finish on the project as a whole.  Some exterior trim, some interior pieces, etc. but overall I’m stoked about driving it soon for some summer fun.  

 

 

 

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Edited by Scott Knecht
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Scott.......I just went thru this thread again and I am very happy to see a smiling face.....and thats just from the car as its looks like its getting some paint in the future so it will be pleased.............oh.....and theres some bearded guy also with a smiling face in the last pic..........lol............regards from Oz.......andyd. 

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