how does the power assist steering work
how does the power assist steering work
Hotshot
Joined: Aug 2006
Posts: 10,764
Likes: 39
I took all of it out & put in a chevy gear box ,,steers like a car ...
with my old set up,,you had to let it know what you were going to do in advance with a bump of the wheel left ,, (if you were going to turn left ,,) it sucked ....
Tuned
Joined: Feb 2003
Posts: 355
Likes: 0
From: Oregon
It uses a manual steering box with the pitman arm attached to a ball stud on the front end of a control valve pressurized by the power steering pump. The rear of the control valve is attached to the driver's side steering knuckle by a tie rod end looking thingy. The valve pressurizes a hydraulic power cylinder on the center (drag) link. The ball stud on the valve moves back and forth with the pitman arm, either extending the ram on the hydraulic cylinder or retracting it, depending on which way you're turning. The ram moves the center link left and right, in turn moving the steering knuckles.
There might be more to it than that, but that's the way I understand it, based on staring at my '76.
A lot of people say it's the worst piece of crap ever invented, but I don't think it's that bad. The only issue I have with it is that some the the parts are getting hard to find, and run big $$ when you do find them.
One thing I didn't know until recently is that Ford used a similar setup on their cars in the 1960's.
There might be more to it than that, but that's the way I understand it, based on staring at my '76.
A lot of people say it's the worst piece of crap ever invented, but I don't think it's that bad. The only issue I have with it is that some the the parts are getting hard to find, and run big $$ when you do find them.
One thing I didn't know until recently is that Ford used a similar setup on their cars in the 1960's.
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 785
From: Simi Valley, CA
ALL Ford passengers cars used power assist P/S from 1953 thru 1964, except 1961/64 Birds & Lincolns.
1965/71 Falcon/Fairlane/Torino/Montego & Comets (thru 1969) / 1965/70 Mustang/Cougar / 1970/77 Maverick/Comet also used this setup, as did 1969/74 Econolines.
Power assist P/S was used on F100/250 4WD's thru 1976.
There are two different P/S control valves and related parts.
Garrison (used before serial # T80,001) and Bendix, (used after serial # T80,001).
The parts do not interchange.
1965/71 Falcon/Fairlane/Torino/Montego & Comets (thru 1969) / 1965/70 Mustang/Cougar / 1970/77 Maverick/Comet also used this setup, as did 1969/74 Econolines.
Power assist P/S was used on F100/250 4WD's thru 1976.
There are two different P/S control valves and related parts.
Garrison (used before serial # T80,001) and Bendix, (used after serial # T80,001).
The parts do not interchange.
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
I couldn't agree more, it's not the POS most would have you believe, any mechanical system that's been neglected for over 30 years is going to be troublesome, but when maintained these power assist systems function just fine, mine is 33 years old, all original, and works perfectly.
More Turbo
Joined: Jun 2006
Posts: 601
Likes: 0
I'll throw my 2 cents in. I have the power assist in my 74 high boy. It works flawlessly, even with my lift and 39.5 swampers. I can run 60mph on the highway steering it with 1 finger, and it doesn't wander at all. I've said it before, it's actually a good system when working properly. I bought a 79 steering box 2 years ago, based on all the negative things I heard about the power assist, and the 79 box is still sitting in the back of my shop. At this point, I see absolutely no reason to swap. The only drawback I see in the power assist, is the cost of parts like mentioned earlier.
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
I'll throw my 2 cents in. I have the power assist in my 74 high boy. It works flawlessly, even with my lift and 39.5 swampers. I can run 60mph on the highway steering it with 1 finger, and it doesn't wander at all. I've said it before, it's actually a good system when working properly. I bought a 79 steering box 2 years ago, based on all the negative things I heard about the power assist, and the 79 box is still sitting in the back of my shop. At this point, I see absolutely no reason to swap. The only drawback I see in the power assist, is the cost of parts like mentioned earlier.
Trending Topics
Freshman User
Joined: Oct 2006
Posts: 26
Likes: 0
Truck Valves
At its most basic - the steering box moves the ball stud, which shifts a spool valve in the control valve housing. This directs pressurized fluid to a hydraulic cylinder, which them pushes the steering linkage.
When the ball stud is moved off-center, all the hydraulics are trying to do is re-center the ball stud. It does this by moving the linkage, which just happens to steer the truck.
It is not a bad system at all, when set up properly and in good working condition. A lot of systems tend to be neglected and receive a lot of physical abuse from underneath the truck, and this is where most of the problems come from.
Most of the rebuilding I do is Mustangs, Falcons and such, but in the last couple of months I have rebuilt three Bendix-style truck valves. They were is really good condition, compared to most that I have seen, and didn't have the usual rust damage inside, so they turned out really nice. I think the later Bendix style valve is much better than the earlier Garrison valve.
When the ball stud is moved off-center, all the hydraulics are trying to do is re-center the ball stud. It does this by moving the linkage, which just happens to steer the truck.
It is not a bad system at all, when set up properly and in good working condition. A lot of systems tend to be neglected and receive a lot of physical abuse from underneath the truck, and this is where most of the problems come from.
Most of the rebuilding I do is Mustangs, Falcons and such, but in the last couple of months I have rebuilt three Bendix-style truck valves. They were is really good condition, compared to most that I have seen, and didn't have the usual rust damage inside, so they turned out really nice. I think the later Bendix style valve is much better than the earlier Garrison valve.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Thread Starter
|
Junior User
Joined: Dec 2005
Posts: 91
Likes: 0
ok so if I was to move the setup out of my 76f250 and put it in a john deere tractor to eliminate costly steering worm failure... I could replace one of the two tie rods on the pitman arm with the drag link aka garrison valve or is it a bendix??... attach the ram to the other tie rod... and I would have power assist steering in my tractor right?????
More Turbo
Joined: Jun 2006
Posts: 601
Likes: 0
ok so if I was to move the setup out of my 76f250 and put it in a john deere tractor to eliminate costly steering worm failure... I could replace one of the two tie rods on the pitman arm with the drag link aka garrison valve or is it a bendix??... attach the ram to the other tie rod... and I would have power assist steering in my tractor right?????
Freshman User
Joined: Jul 2008
Posts: 42
Likes: 0
ok so if I was to move the setup out of my 76f250 and put it in a john deere tractor to eliminate costly steering worm failure... I could replace one of the two tie rods on the pitman arm with the drag link aka garrison valve or is it a bendix??... attach the ram to the other tie rod... and I would have power assist steering in my tractor right?????
I did something similar to what you are wanting to do about 35 years ago. I had a 1947 Plymouth that I turned into a streetrod, with a 413 Chrysler engine with a six pack setup on it. I wanted power steering, so I took the necessary parts from a 57 Ford car and adapted them to the Plymouth. It worked pretty good, but I wanted a faster steering, so changed the length of the steering arms to quicken it.
However, I wished after doing it, that I had not quickened it as it took more power to turn the wheels than if I had left it slower. Otherwise it worked quite well.
Jim.
###
Thread
Thread Starter
Forum
Replies
Last Post
704 dentside man
1973 - 1979 F-100 & Larger F-Series Trucks
7
Jul 28, 2013 03:30 PM
tylstruck
1973 - 1979 F-100 & Larger F-Series Trucks
1
Jan 12, 2008 11:45 PM
johnorser
1973 - 1979 F-100 & Larger F-Series Trucks
26
Oct 7, 2003 09:31 AM
leadmic
1973 - 1979 F-100 & Larger F-Series Trucks
3
Jul 9, 2002 01:34 AM