Power steering for postwar Mopar

[Tim Keith]

Some have had success in adapting late model electric power assist steering to older vehicles. The units that I have become aware of attach to the steering column and act in multiplying the effort that the driver inputs to the steering wheel.  There are no pumps or hydraulics.  You can search street rod and off road forums for examples of this type of steering conversion.   One popular unit is from a Saturn Vue.  To save fuel many manufacturers are using these units, there is no power steering pump.   Many units require a signal from the ECU of the vehicle, there are vendors that supply a low cost device that supplies the necessary signal.

 

Here is an introduction to this power assist method

   http://preview.tinyurl.com/kbst5s9

Edited April 18, 2014 by Tim Keith

[DonaldSmith]

An electric unit may be a good solution.  

I had looked at Unisteer, but they recommend against locating the unit under the hood, where it would be exposed to heat and moisture.  And I could not visualize the unit behind the dashboard; the steering column would have to take a sharp detour to get to the motor without disrupting the shifting rod.  And the postwar DeSoto is very busy behind the dash, if it has the double heater.  

 

I looked at the preview, and it involves replacing the steering column.  That would lose the stock appearance. 

Edited April 18, 2014 by DonaldSmith

[Tim Keith]

Most of the time the unit fits under the dash. I think that is where it is mounted on late model cars as these units may be sensitive to underhood heat.  There are several units to consider.  Because of fuel economy requirements these assists are widely used to avoid the need for a power steering pump.   A vendor supplies a $60 device that enables the Saturn system to function in another vehicle.  Other auto manufacturers may have different designs that do the same thing.  Almost any steering system modification would alter the stock appearance of a S11, but this leaves the bulk of the steering stock

 

https://www.youtube.com/watch?v=1SgLgb2sjBo

Edited April 18, 2014 by Tim Keith

[Tim Keith]

Another option could be the Chevy Cavalier power rack n pinion with the Toyota MR2 electric pump.  This is the electric power steering pump from the MR2 "Spyder".  This is a relatively popular upgrade that many have made to newer cars of various makes. I think it could also work for the DeSoto if the power Cavalier RNP provides proper steering geometry.  The Prius also has electric power steering pumps, but I've only read about using the pump from the later series of MR2 sports cars.  The gasoline motor of the MR2 is mounted behind the driver, so it was impractical to run conventional motor mounted hydraulic pumps.  It is common to use this swap to clean up the engine comparement in a modified vehicle.

[DonaldSmith]

Update:  Pump installed.  Belt and hoses ordered.

 

Pump with bracket and spacers.   Squared holes in bracket for carriage bolts.  (Adjustment will be vertical, instead of pivoting the pump.) 

 

 

Pump installed.  Belt too long, held tight for photo.  Shorter belt on order.  Carriage bolts in slots in large bracket frame, for adjustment.  Shorter carriage bolts are in the plan.

 

 

The belt and hoses will be here Monday.  Then I'll fill the pump and gear, and put everything back together.  We're coming down the pike, on the last lap, and other suitable metaphors. 

[builtfercomfort]

Looks good. What is the pump from?

I'd suggest you leave a little adjustment in the pivoting arm as it's much easier to adjust for final tension than the up and down / two bolts method.

[DonaldSmith]

First, I found on line that mid '70's Mopars had 1-1/4-inch pitman shafts, like my DeSoto has.  I ordered the gear and pump from O'Reilly's on line, but found that that the gear for a '70's Mopar came without a fitting that was made of unobtanium, and the bosses and holes were in the wrong places anyway.  I returned them to the local O'Reilly's,and got next-day availability on the right parts, and without shipping charges.  And the gear had four threaded bosses on the right side, which was the left side.  

 

The gear is Cardone 27-6579, and the pump is 20-6117.  There may be a host of other combinations that would work, but I didn't know how to access some sort of comparison chart.  Sometimes I'm just to timid to pursue matters for fear of making a pest of myself.  

 

I still have some pivoting adjustment at the pump. but since the belt is almost vertical, pivoting might not make much difference.  

 

So this weekend I'll sit around, waiting for the belt and hoses to arrive Monday.  I can clean up the workshop and garage, and do some minor items on the checklist, or maybe sit in the magic chair for a few spells.

[DonaldSmith]

The hoses are in. 

I assumed that the red plug on the steering gear was for the pressure hose, and the green for the return.  Hey, these hoses don't fit! 

 

Long call to Cardone technical, the rebuilders.  (They were shorthanded.  I kept hearing the canned lectures on flushing the system, replacing the rotten hoses, and restarting certain GM cars.)  No, the pressure fittings are 11/16ths on the gear and 9/16ths on the pump.   The return is 5/8ths at the gear, and slip-on at the pump.  Gee, the hoses all fit now! 

 

I topped off the reservoir.  Tomorrow I'll spin the engine, to get the voids out of the fluid.  Then it's resolve the radiator relocation, per "pulleys and belts". 

 

 

I'll update the power steering news as it develops.  

[Don Coatney]

Looks good and I applaud your efforts and reports on this "how you did it" upgrade.

[DonaldSmith]

Final Report (I hope):

 

This morning we dropped the radiator in (my wife helped me), and I connected the hoses and added water (antifreeze will come after leak-check).  Since the radiator moved only a half-inch to three-quarters of an inch, I used the existing hoses.  I'll check later for leaks. 

 

I charged the battery, and this evening I cranked the engine over.  After moving a hose clamp screw which the fan was hitting, I started the engine.  I moved the steering wheel right and left, no difference; then right and left again, and POWER STEERING!   IT'S ALIVE!

 

The pump reservoir was low, with foaming fluid, so I topped it off and I'll have to let the foam settle out.  Enough for today!  

 

Tomorrow I'll actually drive the car out of the garage, shut down the engine and check for leaks, start it up again, and look under the hood while the engine is running.

 

What follows will be a period of to-do items and shakedown cruises, of gradually increasing lengths.   I'm figuring the month of May for the tweaks and fixes, June to rest and to do maintenance, and early July to prepare for the National DeSoto Club Convention, which will culminate in the car show on Saturday, July 19th.  I expect to do quite a bit of showing off.  

[Don Coatney]

I hope to see you here in the Fort on July 19.

[James_Douglas]

Yesterday I located the steering box so that I can connect it with the steering shaft.  I rotated the box about an existing hole.  I carefully marked the location of the new hole to be drilled in the frame, and managed to drill the hole a half-inch off.  

 

I have a new-found sympathy for Wiley Coyote.

 

I supported the gearbox with a come-along hoist hooked to a pipe across the fenders.  Of course, the rope sling on the box was too loose to hoist the box high enough.  Re-sling it.  And the box was not square to the frame.  Twist and shove.  I used long threaded rods instead of bolts to pull the box against the frame.  That works well.  The threaded bosses on the box are not flush with the frame, so I'm adding spacers.  Get one threaded rod engaged, and the second rod should screw right in, if the dumb hole is in the right place.  Once everything is secure, I can replace the threaded rods with real bolts.  Well, that's the plan.   

 

It's cold, and this morning we are getting a light snowfall.  Eventually I'll get back outside.  (I have to work with the garage door open, since the car barely fits and I have to get around the front if of it.)  I'll double-check the dimensions and cobble the hole to fit.

 

I still have the challenge of relocating the alternator, locating the power steering pump, and re-doing the pulleys and belts.  But one frustration at a time.  Sufficient for the day is the evil thereof.  

 

 

Hey Don.  Looks like things are coming along.  I do hope you are keeping detailed records and templates.  You never know when I may need them!

 

One thing to consider, I know of experience, when mounting a power steering box on a frame rail that was originally a manual box...often after a few years the pressure causes the frame to crack.

 

I would suggest that when you are satisfied with the location of the mounting holes, that you drill them out and place a steel pipe with an ID the size of the bolt OD into the frame and have it welded on both sides and then ground smooth.  You can also add a plate on the outboard side for extra strength.  I did a car many years ago like you are doing and about year 2 the frame started to crack from the extra pressure.

 

Good luck and MORE photos.

 

Best, James

[James_Douglas]

Desperately searching for double groove pulleys.  Contacting my DeSoto Club sources.  Been advised that the double groove pulleys for the early 50's are scarce, since Chrysler made few cars of that vintage with power steering, maybe one per week.  But working on it. 

 

Backup plan:  Leave the single groove water pump pulley and alternator pulley, maybe even with the present wide belt.  Add a narrow pulley to the crankshaft pulley, where there is some room to add on.  Mount the power steering pump low, and run it of the second crankshaft pulley.  I mocked it up, and it seems doable, but the fan blades might be an issue.  If this layout works otherwise, I can cut the fan blades back.  I have a pusher fan as backup at low speeds, but it runs off my auxiliary battery, so I don't want to get rid of the belt-driven fan.

 

DSCF3934.JPG

 

 

Don, would the Desoto/Chrysler generator-pumps work from 1954 (6POS) ?  JAmes

[DonaldSmith]

James:

 

The frame:  You've ... "been there, done that".  Point well taken.  Reinforcing the mounting area of the gearbox is on my to-do list.

 

DeSoto/Chrysler generator-pumps:  One of the DeSoto gurus told me that the early '50's Mopar power steering setups, including the double pulleys, are extremely rare.  So I gave up on them, in favor or readily-sourced parts.  And I wouldn't want to give up my alternator.  

 

Also, I don't know if the generator/pump would suit the later steering gear designs.  I suspect that the early '50's steering column/gearbox, if you could get one, would not adapt readily to the postwar Mopar setup.  We know that for 1949 they changed the orientation of the gearbox.  I don't know what the early '50's orientation is. 

[DonaldSmith]

Got the air out of the power steering fluid (no more growling).  Got the pump belt tightened.  Putting the car back together.

 

Had to adjust the gearshift linkage before driving the car out of the garage.  

 

The wheel turns easily!  (Careful not to wear flat spots in the tires.)  

 

Not quite ready for the test drive. A few items left on the to-do list.

[DonaldSmith]

Final Report:  (Barring breakdowns)

 

I took the car around the block today.  Power steering - sweet!

Maneuvering in the driveway and parking lots will be so much easier now.

I have to tighten the belt a little, so it doesn't squeak at full turns of the wheel - tighten it just enough so it doesn't squeak. 

 

Now onto my other pre-convention punchlist items...... 

[Jim Yergin]

Congratulations.

Jim Yergin

[DonaldSmith]

UPDATE:

 

In tightening the belt that drives the pump, I noticed that the bracket was twisting.  The more I tightened the belt, the more the pulley was pulled out of line.  (I had fabricated the bracket myself, out of hardware store angles.)   

 

 

I'll call it a "prototype bracket", then I won't feel bad about removing it and having a man fabricate a much stiffer bracket.

 

My dad used to fix a lot of things himself, but  sometimes he would hire a man to do it .  Once, when something came up, I asked my dad:  "Are you going to fix it yourself, or have a man do it?"  He laughed.

 

Am I sad? Am I dejected?  No, actually I'm enthused.  I can support the pump temporarily, remove the bracket, and design a stiffer bracket that will be the envy and awe of everyone.  

 

I allowed time for such occurrences.  It's not even mid-May, and the Convention is not till mid-July.  

 

So much for now.  

[James_Douglas]

Don,

 

Make sure you take a moment and look over my post on the steering bushings (Chrysler & Desoto and really only on the big heavy cars like Dons) on the Desoto club site.  With power steering you may want to order a set of the harder ones early Monday before they make mine...

 

James

[DonaldSmith]

Here's a photo of what I cobbled together to replace the resilient bushings that turn to mush:

 

 

I forget what I used, probably PVC electrical fittings within brass bushings.

 

We'll see what's left of them. 

Edited May 9, 2014 by DonaldSmith

[DJ194950]

Donald- your quite the (cobbler) !!

 

Doug

[DonaldSmith]

I solved the twisting of the bracket (or the two brackets: an aftermarket bracket at the pump itself, a curved shape cut from steel plate; and a rectangular bracket which I fabricated from steel angles). 

 

I added a link (carriage bolt and clip angle) from the rectangular bracket to a bolt at a water pump fitting:

 

 

This link worked, once I tightened the bolts holding the curved plate to the rectangular bracket.  No more squeal at full lock, no twisting of the rectangular bracket.  

 

But before I tightened those bolts, the plate pivoted forward, and the fan went "ping, ping,ping" against the pump pulley.  (Tolerances are tight.)   To keep this from happening if the bolts should loosen, I added another link (eyebolt and clip angle) from the back of the pump to the rectangular bracket:  

 

 

I keep thinking that this it it, I'm done with the power steering installation.  We shal see.   

[TodFitch]

I hope your water pump plain bearings (bushings) hold up. On my older car I kept having to have the water pump rebuilt as the bushings would wear and then the shaft would start wobbling so the seal would leak washing grease out of the bushings, causing the bushings to wear more. Rinse and repeat. Turns out that solution to the whole problem was to stop adjusting the belt so tight. (Internals for my pump are the same as later ones but the housing is different as the '33 and '34 blocks are different than later engines, so I can't buy a new pump but I can easily have mine rebuilt.)

 

If you have a pump with ball or roller bearings you should be okay. But if you have the older style with bushings, well, I wish you luck.

[DonaldSmith]

Don't overtighten the belts - a good caution.

 

I just tighten the belts enough to stop the squeak.  I get some deflection when I push on the belt between the pulleys.  

 

One thing going for me, the power steering pump works off the crank only.  The belt does not go around a pulley at the water pump.  So I should be OK in that regard.  But I expect that something else will rise up and sting me. 

[Tim Keith]

I saw a '91 Toyota MR2 Spyder with the electric power steering in the Pick-N-Pull, but someone had already removed the pump. The car still had electric hydroboost for the brakes.   If I see one of these again I'll get the pump as it would have only cost $21.  This type of system might become mainstream in the future as automakers find ways to improve fuel economy, but currently these MR2 pumps go for up to $300 on Ebay.   These pumps also work great to add power steering to a tractor.  The Toyota system is speed sensing, in that the ECU of the vehicle provides a signal that reduces the pressure depending upon vehicle speed.  The pump produces the greatest pressure at parking lot speeds and cuts back at freeway speeds.   The default output when the control signal is missing is okay for most steering, but the pressure can be varied by using another device.  The pump is compact so you can tuck it out of sight.

 

I have a computer program that searches the inventory of the local PNP, I hope to see if I can get there first for good stuff like this.  Electric cars have similar systems.