Rack and pinion in my ‘48 Plymouth

[Bob Riding]

16 minutes ago, Scott Knecht said:

Me too.  I do know the kit includes the brackets, adapter sleeves to connect tie rods to outer ends and of course the u-joint I mentioned earlier in the post.  They don’t delete parts from the kits unfortunately.  
I also got the heads up the kit requires outer tie rod ends from a ‘04-‘05 Explorer.  Apparently they use the same taper.  We’ll see. 

Me too, too! My kit came last week- I'm waiting for the Detroit Axle R&P unit to arrive. Detroit Axle Remanufactured R&P  I have the other bits that I will need from my junkyard rack. I will send the junkyard rack back to Detroit as a core, which will get me some kind of extra special warranty (I believe). I guess Scott and I are in a race! Actually, I'm not in a hurry, but will document my progress as I go.

[Scott Knecht]

19 minutes ago, Bob Riding said:

Me too, too! My kit came last week- I'm waiting for the Detroit Axle R&P unit to arrive. Detroit Axle Remanufactured R&P  I have the other bits that I will need from my junkyard rack. I will send the junkyard rack back to Detroit as a core, which will get me some kind of extra special warranty (I believe). I guess Scott and I are in a race! Actually, I'm not in a hurry, but will document my progress as I go.

Very nice.   I’ll take my time and learn from you.  Lol

[Bob Riding]

It's a deal. I have a kid (late 20s now) from my old Boy Scout troop who is a professional welder. He did my floors on the '52 and I'm sure will be able to make the R&P work. News at 11...

[Scott Knecht]

Woo hoo! 

[Scott Knecht]

So the FatMan kit came earlier this week.  I’m a bit underwhelmed at what you get for $324.  But as I said before why reinvent the wheel.  Plus I get it.  These guys put all the time into designing and testing their product to keep us hot rodders rolling along.  There is also a fairly comprehensive instruction sheet included.  Hope to get started on this once I button up the engine and trans and get them installed. Stay tuned.  

[Bob Riding]

I ordered the wrong outer tie rod ends from a ‘04-‘05 Explorer, but they are 1/2" internal threads (female end) and the junkyard arms are almost 3/4". Which ones did you buy?

[Scott Knecht]

This is the Napa number for the Explorer outer tie rod end. They are I believe 14mm inside diameter.  They fit the FatMan adapter perfectly. The other end of the FatMan adapter is 18 or 19mm and it also fits the Cavalier inner rod perfectly.  

Edited March 13, 2021 by Scott Knecht

[Scott Knecht]

Hello again.  Finally got some time to mock up the rack in the ‘48 today.  While I have things close, I’m a way off from any welding yet.  There are several issues I must address. 
First the rack still must go higher or I need to fabricate a plate to bolt to the rack tie rod holes and raise the tie rod pivot points.  As they are presently, the tie rods go up slightly to the steering arms while the control arms are level.  This is creating slight bump steer because the inner ends are not at the height of the control arm pivots. ( I have the springs removed to make cycling the suspension easy) The second issue as you can see in the photos, one of the Cavalier rods is not like the other.  The fat one has a significant bend in it. That’s actually the driver’s side for the Cavalier but I have them backwards in the photos as I was trying to see a difference in fit.  I think I’m going to order another passenger side Cavalier rod to match the other.  
Lastly I really need to slip the engine back in to check clearances before I attempt to modify the fat man mounts or anything else.  Stay tuned.  

[Sniper]

Thanks for the update, I am following this one closely.

[Bob Riding]

Me too! Great photos. I am at the engine mockup stage and need to make sure I leave enough room for the rack. My frame is different than yours- a '52 is probably narrower where the rack will sit. Once I figure out where the 360 will be,  I'll concentrate on the rack positioning. What is your thinking on having matching Cavalier rods- aesthetics or function?

[Scott Knecht]

Wow had to trim the firewall? 
I was able to get good set back with a big hammer.  Lol

looks good in there!

As I said the Cavalier driver side tie rod has a large bend in it.  Probably to clear something in the chassis. I’m not too familiar since I bought all new stuff and didn’t go to the yard. 
Anyway the passenger side rod is straight except a slight bend at the end which points it rearward slightly right to steering arm.  It seems to work well on both sides.  The driver’s side rod ends up there but in a more elaborate way.  It would contact the frame because of the bend if I keep it on the passenger side.  (See photo) Hard to tell here but it actually rises up where on the drivers side it would go down.  

And yes I guess aesthetically it would look better having matching rods.  But I’m funny that way.  Hahaha

[Scott Knecht]

Well I got some time to get farther along on the Plymouth today.  After sticking the LS back in with the retro swap oil pan screwed on, I finally gave a few tack welds to the Fat Man mounts.  Of course that was only after measuring everything 65 times.  Lol 

As you can see in the pictures the inner pivots are not centered.  The engine is set about 3/4” to the passenger side in the frame which exaggerates it a bit.  At any rate I had to move the rack slightly to the driver’s side to gain header clearance for the steering shaft.  However this will enable me to build the plate to bolt to the rack which will raise and center the tie rod pivots exactly with the lower A-arm pivots which should completely eliminate the slight bump steer I’m still seeing when I cycle the suspension.  

 

Edited April 3, 2021 by Scott Knecht

[Sniper]

Very nice work, wish I could weld.

 

Regarding bumpsteer, oh wow does my 51 have it bad, all stock steering.  I was enthusiastically driving it the other day and just about bumpsteered myself into oncoming traffic.  It was an uphill sweeping right hand thru an intersection and when I got to the top of the hill (middle of the interesection) the pavement was rough and it hopped itself left on me.

 

Glad you sorted the bumpsteer out.    

[Scott Knecht]

Thanks.  Yeah I’m learning as I go on this.  I’ve restored a lot of cars in my years but never did work like this.  The most I’ve done with swapping stuff is a few S10 V8 swaps. 
This is all new to me.  I should’ve paid more attention in geometry class.  Hahaha

I have been mig welding for about 35 years. So I’m not too scared when it comes to that. 

Edited April 4, 2021 by Scott Knecht

[Andydodge]

What are you guys doing about the limited throw that the rack & pinions generally have which results in a large turning circle?..........my car with the 9" narrowed Austin 1800 rack(pictured, yellow sump) has modified steering arms which give a better turning circle......however the pic I have attached shows the stock steering arms mounted ONE BOLT forward from their original position.........which brings the steering arm tie rod hole closer to the kingpin pivot point and results in a shorter turning radius ..........I can't remember who did this or came up with this solution however it appears to offer an answer to this problem which arose using the Cavalier style rack...........any comments?..............andyd   

[Scott Knecht]

Wow that’s a great idea! Looks easy enough to accomplish.  I was concerned about that problem too but thought I could get used to it.  Now you’ve got me thinking. 
I’ve heard of guys cutting and re-welding them but I’m in no way comfortable doing that.  Moving them forward really seems like it might solve that problem.  I’ve also heard the rack with stock pump pressure has no feel.  Moving the arms closer to the kingpin may solve that too because of increased force to turn them.  I shall investigate this possibility and let you all know what happens. I am curious though how this will affect the bump steer if the rods are not shortened and the inner pivots moved outward to match the A-arm pivot lines? Guess we’ll see what happens.  Thanks Andy!

Edited April 4, 2021 by Scott Knecht

[Andydodge]

Personally if I were doing all this again, rather than 45yrs ago I'd use a Cavalier(Camira here in Oz) rack, and not be concerned about the pivot points as they are reasonably close to the pivot points of the lower A arms.........but instead of having the steering arms cut, shortened 1",forge welded & x-rayed by an automotive blacksmith as I did in 1975 I'd move the arms forward as it seems to me to offer a great alternative............funny thing is just recently a mate gave me a rack from a car we can't identify and it was used in another old hotrod but it also has been narrowed to suit an Oz GM Holden independant front suspension and seems to have a similar pivot measurements to my narrowed Austin 1800 rack..........so I've got them all over the place incl an Oz Camira/Cavalier rack...............fun & games, lol..............andyd 

[Bob Riding]

Brilliant!  However on my '52 front end, there are only 2 holes...can I swap out older steering arms without screwing up the geometry?

[Scott Knecht]

Yeah what they did Bob, from what I can see, was weld on an extension to the disc brake backing plate then put a spacer under the steering arm. I could see this being a pretty easy fix.  If you have aftermarket steel backing plates that is.  I’ll try work on it this week and let y’all know what happens.  

[Scott Knecht]

Alright guys I couldn’t wait till Easter dinner was over.  I had to run down to the shop and check out this mod.  Well..... got a clearance issue with the lower control arm. The spindle won’t rotate to the stop. At least on my ‘48. Not sure there’s enough meat to remove but I ain’t giving up on it just yet.  Also I’m going to slip the rotors on the hubs to be sure there’s clearance. Stay tuned. 

Edited April 4, 2021 by Scott Knecht

[Andydodge]

Scott & Bob.......I wish I'd kept the details of who did this steering arm trick but it was someone here in Oz and the pics were posted on this forum but it would have been 5-10 yrs ago........the actual car going by my naming of the pic was a 1957-62 Oz Chrysler Royal which was an Oz bastardised 1953/54 Plymouth with 55/56 fenders grafted onto it.........see attached pic of a 57 and 62  version, note the basic 53/54 body shell, the suspension was the same up to the Oz 1962 model..........I used the 1962 stub axles on my 1940 Dodge and they are the same as that used on the 1941 and 1948 US Plymouths so I assume thru to 1954 and newer.............it may have been that the disc brake adaptor plate was slightly different or maybe the steering arms were swapped side to side.............unfortunately I can't help with any more info but this was on a car that was one the road here in Oz..................andyd

[Scott Knecht]

Yes Andy I believe that to be a very easy fix on vehicles with clearance.  My driver’s side (left side here in the US) as shown in the picture has slight interference.  However I totally forgot the right side steering arm is bent like an “S” so the tie rod end comes up through the bottom (opposite the other side). The “S” shaped arm has ZERO clearance of the lower control arm when I moved it forward.  So I’m back to the drawing board.  I’m so enthralled with the idea of a tight turning radius now, that I’m considering making arms from scratch out of heavy bar stock.  Other than reaming the taper for the tie rod end, it seems pretty straight forward.
But so did installing rack and pinion steering.  Lol 

[Bob Riding]

Andydodge and Scott -Thanks for the updates. I have a donor 56 Plymouth Suburban that I wonder about it's steering arms. More to investigate...

[Andydodge]

AFAIK the steering arms attachment bolt holes are the same size and spacing at least up to 1954, maybe 1956 but there are probably a few different "drops" depending on the various years, it would be worth checking various steering arms to see what if any differences there are as for making new arms to suit I'd be using 1" plate flame cut to shape & drilled, you could then have the ends reamed to suit the Cavalier tie rod ends.........and it maybe worth checking whether installing the arms on opposite sides even if upside down to see if that makes any difference as being upside down in itself won't make any difference in this application.............andyd   

[DJ194950]

Might want to read up on bump steer and how to check.

 

Tools for checking are available online with a web search-" bump steer checking tool". Much info/stories are there.

 

Also  tried to attach but had some brain fade and did not get it done.  Longacre i think it was -had  some checking/ teaching info and a reasonable price?  tool.

 

DJ