I am trying to figure out how to put a R&P on my 47 Plymouth and having no luck. I am wondering if anyone has done this before and what they have done and maybe see some pictures and hopefully I can figure this out. Any suggestions or help would be greatly appreciated!!!

Welcome to Moparts.
Rack & pinion steering has been installed in several 46-48 Plymouths.

If you are retaining the original independent suspension, a rack from a 94-97 Chevy Cavalier works very well. Those GM racks have been used in many other GM cars since the Cavalier. That rack has the inner tie rod ends attached at the center of the rack, rather then out on the ends like most racks. They were available as a power or non-power rack, but the non-power racks are much more difficult to find. A standard Mopar power steering pump will work well if you pickup one of those pressure reducing kits that fit inside the pressure hose, or one of the dial a pressure things. Should find both options on a google search for power steering pressure reducers.

The racks mount up nicely behind the Plymouth front crossmember. You will have to make simple brackets to weld to your frame. The outer edges of the rack match the width of the frame, mounting the rack is pretty simple.

The center tie rod attaching point allows you to make a center link and use your original tie rods if you wish (replacement tie rods are readily available, they are the same as 70s Dodge trucks.) You may also modify the original Cavalier tie rods, or you can modify tie rods from a 93-96 Dodge Intrepid. Making a center link is easier.

You will have to modify your steering column, and you have to locate the special GM Ujoint that attaches to the Cavalier rack. I suggest you try to locate the short GM shaft & joint from a junk yard. They may be available at parts stores by now. The rack is pretty cheap, with a very low core charge if you buy a rebuilt rack from a parts store (shop around).

The rack will have a larger turning radius unless you modify (move the tie rod hole 1" I believe) closer to the spindle the Plymouth steering arms.

I used to have pictures,I'll see if I can find them.

If you venture over to www.jalopyjournal.com and check on the hokey azz (ss) message board, then do a search for "rack & pinion for 46 Plymouth" you should find several threads with pictures and updates. I'm "50dodge4x4" over there and have been involved with several of those threads. Gene

welcome to the board ! one other item you should also consider if retaining the original front suspension, is the re-location of the upper shock mount. as the originals are mostly useless because the shock is mounted between the control arms, fabbing an upper mount that connects to the chassis will be a great improvement in both ride and handling.

Thank you for the help Gene. If you can find those pictures that would be great! I am going to do that search you told me about as well. Thanks again. Joshua

Is there any threads with pictures of the gabbing and relocating of the shock mount? Thank you for your help!! Joshua

Sorry, I looked, the pictures I had of the rack & pinion must have been on my old Computer.

Try a Google search for "rack & pinion steering for a 46-48 Plymouth" The 39 through 52 Mopar front frame is basically the same. What works on the 46-48 Plymouth can be made to work on the others. I have simply seen more info available for the 46-48 Plymouth.

I know the pictures I took are still out there online because I saw them referenced a couple weeks ago, someplace. Gene

Shock mounts how-to:
http://www.jalopyjournal.com/forum/threads/shock-mounts-for-older-mopars-tech.215548/

Do you have a diagram like this for making brackets to bolt a rack and pinion to the frame with? Thank you for the post!!

I bought the kit from Fatman years ago, and after I got it realized how simple it is. The Fatman kit does have some adapters that let you use the Cav tie rods with Datsun 510(!) tie rod ends that will work with your stock steering arms.

Here's another way:
Cavalier rack install

[quote=
Here's another way:
Cavalier rack install [/quote]
that's simple enough ! those drawings could be pretty close to possibly be tweeked enough to be used on a plymouth chassis, although i would have to look under one to know for sure, and it has been close to 35 years since i sold my '48 sedan. i have heard of the GM rack conversion for many years, but have not been around a car that has had this done. one question i have is, how good is the turning radius with the conversion ? this just comes to mind because i rode in a 55 chevy [i know, not related to this mod, but..] this weekend that had a rack kit of some kind installed, and it took a 40 acre field to turn around in, plus it really didn't steer all that good to boot. i realize the alignment could have been off, but i wasn't impressed at all ! [nor with the car either, but there is another story there to tell.....] a guy could mod the arms on the plymouth to help with the radius if needed. comments ?

The pictures in that link are very similar to what the brackets I made when I installed the rack in my Plymouth coupe all those years ago. The "center link" that the inner tie rods attach to, in the pictures on the Cavalier rack, is probably about the easiest way of connecting your car (or truck) steering to the rack, and you can use your original tie rods by simply modifying the length of the "center link".

As far as turning radius, on my Plymouth coupe, the radius did increase enough to be noticeable, but not enough to be undrivable. Originally, the Plymouth's of that era had a pretty short turning radius. There weren't any issues with driving,(other then the power steering pump produced too much pressure, which can be controlled by a pressure reducer) but parallel parking might require another round of back and forth. At the time I believe that I concluded that shorting the tie rod location on the steering arm by 1" would have solved the problem, but that was many years ago, and I'm not really sure about the 1" anymore.

The only other issue I remember is that a custom power steering pressure hose will probably be required, things are pretty congested where the pressure hose resides, and I believe the available hoses were all too long, or had incorrect bends in the tubing. NAPA, around here, makes pressure hoses.

The Cavalier rack fits, is pretty easy to install, and works well in these cars. Coupled with the upper shock relocation, a disc brake conversion, a modern sway bar, and a fresh suspension rebuild and these 39-53 Mopars will ride and handle as well as anything, short of a full on race car conversion. If the suspension is all intact, and the frame is straight and not rotted away, a frame clip or replacement is not a requirement, and would be a lot of unnecessary work. Gene

I've only done the R&P conversion on my '38 Chrysler, so YMMV:

I did find myself making more 3-point turns than I used to, but I was able to find some different steering arms (early Dodge truck maybe)that were an inch or so shorter but had the same mounting bolt locations as my original arms. That got me back a good bit of the turning radius I'd lost.

I'll bet a clever guy could work out shorter steering arms for the later cars if the turning radius bothers you, but lots of people seem to find it livable without doing that though.

early corvettes had that same steer from the middle setups----there may be topics linked to their upgrades too....

Was wondering if you could show me what your brackets look like?