Rack and pinion steering for 46 Plymouth

[dale]

Im considering adding rack and pinion steering on my 46 Plymouth.  Id like to know  if all units require power or if they work without and if they dont need power does it make the steering much easier turning than stock.  THX, Dale

[Andydodge]

Dale...curious why you want to install rack & pinion on your car and I ask this as the owner of a 1940 Dodge that has had a rack & pinion setup since 1973 due to a 318 Poly V8 installation..........my car has an Oz Austin 1800 that I narrowed 9" to give me some sort of bump steer reduction and I would NOT recommend doing things the way i did, however over the past decade I have seen quite a few installations of the Cavalier centre pivot rack and they appear to offer the best compromise as far as the bump steer issue is concerned however the Cavalier rack still has the problem that from what I've seen befalls most R&P installs and that is an increase in the vehicle turning circle, albeit with a much more direct steering feel and a reduction in turns left to right........my car uses a manual rack and I've seen pics of both manual and power Cavalier rack installs, I think its just a matter of preference, although the manual version is obviously a more simplier arrangement without any hoses or pump to complicate the install...............as I mentioned my car has a manual rack and whilst the steering is heavy its not really noticeable once the car is moving......I have attached a couple of pics of a US Cavalier rack install that may give you some help tho' its a power rack version, and a V8 install to boot, the 1941 chassis I think is basically the same from the firewall forward as your 1946 car....these pics are from an earlier discussion on steering racks on this forum a couple of yrs ago and unfortunately I didn't make a note of who's car they are from...............anyway trust this helps........also have attached a pic of the Austin 1800 rack in my car for what its worth..........lol........Andy Douglas       

[dndrodshop]

I have had the Cavalier rack on my car since 1999.  I shortened the stock steering arms which lessened the loss of steering radius.  I don't think I got everything back but is very manageable.  Made my own mounts but very similar to the photos above. 

 

I do have the power rack but with the 440 engine weight it works fine without any noticeable bump steer.  Drive to "Back to the 50's" each year and to Florida for the SE Nationals in Tampa and the Daytona Turkey Run in 02.   When people ask how it handles the 70 mph speed limit, I tell them "I can slow down to 70 if I have to."

[dale]

Thanks guys.. So I take it a non power rack doesnt make the amount of force less to turn the steering wheel.  I have a Chevy 350 motor and I believe the weight is about the same or less on the front wheels than the old Plymouth flathead...

Ill be checking into this.

[dale]

Could you describe  "Bump  steer "  ?

[Frank Elder]

1 hour ago, dale said:

Thanks guys.. So I take it a non power rack doesnt make the amount of force less to turn the steering wheel.  I have a Chevy 350 motor and I believe the weight is about the same or less on the front wheels than the old Plymouth flathead...

Ill be checking into this.

The 6 weighs more than the 350.

[Frank Elder]

1 hour ago, dale said:

Could you describe  "Bump  steer "  ?

Google Ackerman.

[MackTheFinger]

http://www.hotrod.com/articles/ctrp-1001-bump-steer-explained/

 

Ackerman has to do with turning, bump steer is a different thang...

[Andydodge]

Bump steer is as the words imply....."steering via bumps".....or the ideal steering senario is that the lower control arms or A arms are the same length as the steering tie rods so that the arc that the lower arms travel thru, up & down is the same as the arc that the tie rods also travel thru or vice versa........if the tie rods arc when going up & down is different to that of the A arms then the tie rods effectively get "pulled" in & out which pulls the wheels back and forth as tho the steering is changing even ever so slightly and is also felt thru the steering wheel............andyd.      

[59bisquik]

2 hours ago, Andydodge said:

Bump steer is as the words imply....."steering via bumps".....or the ideal steering senario is that the lower control arms or A arms are the same length as the steering tie rods so that the arc that the lower arms travel thru, up & down is the same as the arc that the tie rods also travel thru or vice versa........if the tie rods arc when going up & down is different to that of the A arms then the tie rods effectively get "pulled" in & out which pulls the wheels back and forth as tho the steering is changing even ever so slightly and is also felt thru the steering wheel............andyd.      

Andy has bump steer and tie rod length explained pretty good. I have the same rack in my 54 Ford Coupe. The difference being that there is a bracket the bolts to the R&P and spreads the tie rods out so the length matches the A-arm length and that reduces the bump steer issues.

[Andydodge]

59Bis...........thats an interesting bracket arrangement to mount the rack, looks like it uses the original steering box mount holes and I assume the idler arm bracket mount holes on the passenger side...neat setup, also the use of a steel bar to fine tune the tie rod pivot points looks good..........nice to see various ways to skin a cat.........lol............andyd 

[59bisquik]

10 hours ago, Andydodge said:

59Bis...........thats an interesting bracket arrangement to mount the rack, looks like it uses the original steering box mount holes and I assume the idler arm bracket mount holes on the passenger side...neat setup, also the use of a steel bar to fine tune the tie rod pivot points looks good..........nice to see various ways to skin a cat.........lol............andyd 

Yes, you are correct about the mounting on both sides. It was a kit many years ago the floated around the Ford circles. I don’t know if they are around anymore though.

[mrwrstory]

'Tho I redid my whole front end, I've used a manual rack.  One less system to maintain than power. Much easier to steer than the old box and I have a small block Mopar V8.  That said, my wife does not like it so I'm the only one who drives it.  Oh well ! 

[dale]

I think its the radial tires that make for alot of the hard turning of the steering wheel.  Thanks for the info guys.

[Andydodge]

Dale, interesting that you say that re the increased steering effort with radials as I remember when I changed to radials on my 1940 Dodge after running crossplys(this was 40 yrs ago) and also when I went from crossply tyres to Coker radials on the 41 Plymouth about 10 yrs ago, the steering , if anything seemed to be much easier...........I know that the old whitewall crosslys that the Plymouth, an older resto when I got it were unbelievably bad in their ability to weave and follow whatever indentations etc that were in the road and that the Coker Radial Whitewalls made a huge differnce to the steering and reduction in weaving........andyd     

[Niel Hoback]

Stopped or moving at a slow speed, the steering wheel is harder to turn, but driving is much easier. Tread width problem? Dunno.

[DonaldSmith]

Radial tire, bigger, flatter footprint.  I couldn't steer my DeSoto Suburban when stopped.  Very tricky to go slow but fast enough to  steer.  Added power steering. 

[dndrodshop]

On 4/7/2018 at 12:50 PM, dale said:

Could you describe  "Bump  steer "  ?

My car would change toe-in and toe out during the suspension travel. Once I changed to a the Cavalier rack that all went away.

 

[rvannoy1]

On 4/7/2018 at 8:24 PM, Andydodge said:

Bump steer is as the words imply....."steering via bumps".....or the ideal steering senario is that the lower control arms or A arms are the same length as the steering tie rods so that the arc that the lower arms travel thru, up & down is the same as the arc that the tie rods also travel thru or vice versa........if the tie rods arc when going up & down is different to that of the A arms then the tie rods effectively get "pulled" in & out which pulls the wheels back and forth as tho the steering is changing even ever so slightly and is also felt thru the steering wheel............andyd.      

 

 

Very good explanation.

[ply 51]

Hi Folks, I am thinking about putting a rack in my 51 p22 with a small block 340. what year Cavalier is tipicaly

used. I will go with a power rack.

Thanks

[rvannoy1]

ply 51,

I think 1986 to 1992 Cavalier rack is what you're after. That's what I put under my P15. Be aware that there are various steering ratios for the power rack as well as a manual rack too.

Good luck with your conversion.

[DJ194950]

9 hours ago, ply 51 said:

Hi Folks, I am thinking about putting a rack in my 51 p22 with a small block 340. what year Cavalier is tipicaly

used. I will go with a power rack.

Thanks

 

I believe Fatmanfab a company- stills sell the setup for your car.

 

Give them a call.http://www.fatmanfab.com/

 

DJ

[ply 51]

Thanks , I didn't know about the different ratios. What should I be looking for?

 

[ply 51]

1 hour ago, ply 51 said:

Thanks , I didn't know about the different ratios. What should I be looking for?

 

I did a search and found that there is a soft steering and a sport steering. I think the soft(standard) will be fine.

 

[rvannoy1]

 I had both (sport & standard) from scrap yards and realized the sport steering ratio was not for my P15 with the weight of a 354 Hemi. I also installed a manual Cavalier rack and, much to my dismay, I could barely turn the steering wheel while the car was sitting on the garage floor. I still  have mounts welded to my frame for both racks as the manual rack, passenger side mount is approx. 2 inches closer to center than the power rack. I left both mounting brackets in just in case I change the engine someday to a much lighter small block Mopar.

 I will tell you that I've been struggling with my type II GM power steering pump to find the proper pressure and volume that works best with the extra weight of the engine and also the fact that I fabricated new, shorter steering arms to correct for the turning radius that the original steering arms would produce. When you get further along with your conversion let me know if you would like a drawing of my steering arms and mounting brackets. I can also send you photos of the installation if need be.

 

Regards,

Ron