I have done some searches but come up empty on this.

Is there a difference between having power steering and power assist. I have a 78 4x4 with power steering. Pump on the motor, with a power steering box on the frame rail. What I cant figure out is how this differs from power assist. Can someone post a picture showing the difference.

Here you can see the pitman arm attached to the power steering box on my truck.

F150 Modificatins - DSM8's Photos

Sorry cant attach a pic

 

According to forum users, your set up is considered power assist (or Integral Power Steering). Power steering would have a hydraulic ram.

I swapped in the system from a 78 Bronco on my 73 F-100. Love it.

~

 

That is incorrect. Power assist would be a system with a hydraulic ram "assisting" a manual steering box. Integral power steering "integrates" the power assist in the gearbox. There is no hydraulic ram in an integrated power steering system.

-Jared

 

I respectfully disagree on your nuances.. and I didn't say there was a hydraulic ram in the integrated PS system.

Integral power steering has the pump feeding the steering box. Power steering has the pump feeding the hydraulic ram.

 

Um no sir... Power assist utilizes a control valve and a power assist cylinder on the front member...Assisting the manual gearbox.

DSM8 your picture proves that you do not have the power assist set up as there would be a power assist ram from your axle tube to the drag link

 

1978 4WD's did not come with Power Assist P/S. Power Assist is not Integral P/S, the two P/S systems are totally different.

Power Assist P/S applications:

1973/77 F100 4WD / 1975/77 F150 4WD / 1973/77 F250 4WD (1977: High Boys only).

1969/74 Econoline's.

1953/80: Myriad Passenger Cars.

With Power Assist, there is a separate control valve and ram cylinder. The steering gearbox is of the manual type, because...it has nothing to do with Power Assist P/S.

Integral P/S: 1966 thru today F100/250 2WD's / 1969 thru today F350's / 1977 F250 4WD's (not High Boys) / 1978 thru today 4WD's / 1972/96 Bronco's / 1975 thru today Econolines.

With Integral P/S, everything is contained within the P/S's gearbox.

1973/77 F100/150 4WD's / 1973 F250 4WD's / 1974 F250 4WD's before serial number T80,001 used Garrison Power Assist P/S.

1974 F250 4WD's from serial number T80,001, 1975/77 F250 4WD's (High Boys) used Bendix Power Assist P/S.

Garrison P/S parts do not interchange with Bendix P/S parts. Thes two 4WD P/S systems are totally different, sharing only the P/S pump.

1978: Ford changed the P/S pump on everything (includings cars) except Econolines. This pump has a plastic reservoir and dipstick.

1965/77 P/S pumps have a steel reservoir and dipstick. The P/S pressure hoses are specific to each type of pump, so are most of the mounting brackets.

 

Is there an advantage of one over the other when dealing with a lift and larger tires (35") I am considering full hydraulic steering but dont believe that would be the best choice for freeway travel so I am looking to see if there is a better choice and dont know if the power assist is the better choice of the two for this specific application.

 

You do not want Power Assist P/S...almost all the parts are obsolete, mucho expensive when you do find them.

Mounting Power Assist on a non High Boy would be a royal PITA, a modifiers nightmare. Forget it.

 

Well then I guess that makes it easy either run with the stock or work on a ram assist after market application. Thanks for the info, that is what I was trying to determine.

 

A stock 78/9 4x4 steering box is a good place to start, but you do not want to use the stock push / pull steering design for a lifted truk.
Crossover and hydraulic assist is the way to go.

 

To NumberDummy: I have a 1975 F250 4x4. Right now I see that I have the Bendix type power/assist/steering? I just bought the truck and it does not have a power steering pump, it was gone/is gone. Of course it is a bear to steer. If I was to get a pump for it, would it simply be power assist or power steering. I have heard a lot about using a steering box from a 78'-79' steering box. Do you have an opinion on what would be the best way to go to make mine true power steering??? Thanks to You or anyone that can help with this. Shane

 

Assuming the other components are in place, i.e. control valve, power cylinder and supply/return lines you'll have power assist steering, otherwise, it will be just as it is now, basically manual steering.

 

What do you mean, 75F350, when you say to go with a crossover or hydrolic assist is better? Thanks, Shane

 

Ok fellas, this question goes out to all of you guys: I keep hearing that getting your hands on a 78-79 F250 4x4 steering box, to make my 75 4x4 highboy with power assist power steering integral power steering, is hard to find. O'Rielly Auto Parts tells me that they have them, fully refurbished, with a lifetime guarantee for $212 with an $89 core charge. Can anybody confirm this? Is it that easy, or are they selling the wrong item. Thanks, Shane

 

Hi, I have a 77 high boy and I just had the power assist valve rebuilt .. hooked it up and it spins the wheel to the left on its own and stays there tight enough where it stops the pump... need some help please