Bendix Power Assist Steering Question
Thread Starter
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Mountain Pass
Joined: Sep 2018
Posts: 136
Likes: 25
Bendix Power Assist Steering Question
Hi All,
1975 F250 4WD Highboy with Bendix Type power assist steering system.
No leaks, no noise, but steering was very sloppy and loose....lots of wandering - dangerous wandering.
I noticed lots of free play from the Ball Stud at the front of the Control Valve.
During PA State Inspection, I asked the shop to install a new Ball Stud Kit.
The new Ball Stud made no difference and has the same amount of free play as the removed part - see the very short video, i'll set up a longer video tomorrow on you tube.
Another shop, with a master mechanic, that is a lover of our trucks, said he thought those those Ball Studs had an adjusting screw.
I cannot see any evidence that there is a way to adjust and tighten up the Ball Stud.
Any comments or experiences with this situation?
Any advice very much appreciated.
Thanks,
Jimmy
1975 F250 4WD Highboy with Bendix Type power assist steering system.
No leaks, no noise, but steering was very sloppy and loose....lots of wandering - dangerous wandering.
I noticed lots of free play from the Ball Stud at the front of the Control Valve.
During PA State Inspection, I asked the shop to install a new Ball Stud Kit.
The new Ball Stud made no difference and has the same amount of free play as the removed part - see the very short video, i'll set up a longer video tomorrow on you tube.
Another shop, with a master mechanic, that is a lover of our trucks, said he thought those those Ball Studs had an adjusting screw.
I cannot see any evidence that there is a way to adjust and tighten up the Ball Stud.
Any comments or experiences with this situation?
Any advice very much appreciated.
Thanks,
Jimmy
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 784
From: Simi Valley, CA
1975 F250 4WD Highboy with Bendix Type power assist steering system. No leaks, no noise, but steering was very sloppy and loose....lots of wandering - dangerous wandering.
I noticed lots of free play from the Ball Stud at the front of the Control Valve. During PA State Inspection, I asked the shop to install a new Ball Stud Kit.
The new Ball Stud made no difference and has the same amount of free play as the removed part.
Another shop, with a master mechanic, that is a lover of our trucks, said he thought those those Ball Studs had an adjusting screw.
I cannot see any evidence that there is a way to adjust and tighten up the Ball Stud.
I noticed lots of free play from the Ball Stud at the front of the Control Valve. During PA State Inspection, I asked the shop to install a new Ball Stud Kit.
The new Ball Stud made no difference and has the same amount of free play as the removed part.
Another shop, with a master mechanic, that is a lover of our trucks, said he thought those those Ball Studs had an adjusting screw.
I cannot see any evidence that there is a way to adjust and tighten up the Ball Stud.
Upper pic: Ball stud is part of the 3A533 (D4TZ-3A533-A) control valve kit. I assume the shop replaced all the parts of this kit and not just the ball stud.
There's no adjustment screw. 87901-S is a zerk fitting.
3304 (D4TZ-3304-A) is what Ford calls a draglink. Has a joint at the end that wears out, steering becomes loosey-goosey.
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Lower (lower) pic: P/S hydraulic cylinder, it's the same for Garrison & Bendix power assist.
3B711 (D3TZ-3B711-A) is the ball stud, 3C590 (D3TZ-3C590-A) is the kit that mounts the cylinder to the steering rod.
All these part numbers are obsolete. Parts for the power assist systems (especially the control valve seal kits) are getting very hard to find.
Edit: See post #3 for the whole shebang, both Bendix and Garrison are shown.
Laughing Gas
Joined: Feb 2011
Posts: 995
Likes: 317
It didn't sound like the engine was running during video. There will be movement at the ball stud if the power steering pump isn't running or making pressure. When turning the wheel with engine off essentially the movement you see is the centering springs in the control valve compressing one way and the other. When the engine is running and hydraulic pressure present at control valve, as soon as the steering wheel moves the pitman arm/ball stud it shifts the spool inside the control valve sending pressure to the hydraulic cylinder which forces the steering linkage in desired direction. This is why the power assist systems do not have the responsiveness of conventional integral power steering systems.
Do the test again with the engine running. As soon as the pitman arm puts pressure on the ball stud, the control valve arm should immediately start to move via force back through linkage from the hydraulic cylinder. If its not responding very well then there could be a problem in the control valve itself or the cylinder. Are you100% sure all other components in the steering linkage system are tight?
Do the test again with the engine running. As soon as the pitman arm puts pressure on the ball stud, the control valve arm should immediately start to move via force back through linkage from the hydraulic cylinder. If its not responding very well then there could be a problem in the control valve itself or the cylinder. Are you100% sure all other components in the steering linkage system are tight?
Thread Starter
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Mountain Pass
Joined: Sep 2018
Posts: 136
Likes: 25
Hi ND,
Thanks for the reply, good information.
Only the Ball Stud was replaced.
Hi Mark8man,
Correct, the engine was off.
Thanks for the excellent explanation.
I will check with engine on and also check all other components.
One step closer to getting one of those updated modern steering systems.
Many thanks,
Jimmy
Cargo Master
Joined: Jun 2015
Posts: 2,240
Likes: 23
@NumberDummy Do you have torque specs for the bendix control valve? I cant find it in my 74 shop manual, haynes manual, or searching this site. I need the torque specs for nut 3A540 and nut 34033-S. Im going crazy searching for it, thanks in advance.
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 784
From: Simi Valley, CA
@NumberDummy Do you have torque specs for the Bendix control valve? No.
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Laughing Gas
Joined: Feb 2011
Posts: 995
Likes: 317
This is not critical. They just need to be tight, line up hole with slot in nut and install cotter pin. I tighten about as tight as I can get with 1/2 drive ratchet or appropriate size box wrench without straining myself or using a cheater. I know, highly technical description huh. If you have to you can back off an 1/8 turn to line up hole.
I did a complete rebuild on my control valve this winter and so far its working great.
I did a complete rebuild on my control valve this winter and so far its working great.
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Cargo Master
Joined: Jun 2015
Posts: 2,240
Likes: 23
This is not critical. They just need to be tight, line up hole with slot in nut and install cotter pin. I tighten about as tight as I can get with 1/2 drive ratchet or appropriate size box wrench without straining myself or using a cheater. I know, highly technical description huh. If you have to you can back off an 1/8 turn to line up hole.
I did a complete rebuild on my control valve this winter and so far its working great.
I did a complete rebuild on my control valve this winter and so far its working great.
Mountain Pass
Joined: Feb 2020
Posts: 118
Likes: 2
Check to make sure the steering gear box is adjusted properly and not worn out. There is adjustment on the control valve but only done when rebuilding it. There are notes on the net, and the adjustment is more of a setting and controls how fast it responds. It has little effect and only worth mentioning for clarity. If you are not leaking any fluid and it appears to be working fine, then likely you have a loose steering box, bad tie rod ends, or ball joints(kingpins or bearings). If you truck has the stock front axle you should have steering bearings. It may be a good time to jack the truck up, put on jack stands, and do a thorough inspection off your front end.
Gear boxes are known to get sloppy and will effect steering. The steering bearings are known to get worn out and can get dangerous quick. These are very important since slop usually results in breaking the housing and non-repairable for the most part.
Gear boxes are known to get sloppy and will effect steering. The steering bearings are known to get worn out and can get dangerous quick. These are very important since slop usually results in breaking the housing and non-repairable for the most part.
Lead Driver
Joined: Oct 2018
Posts: 7,847
Likes: 2,353
You mentioned upgrading to a real steering set up. just do it.
I've messed with this abortion of a steering set up my whole life and I've grown to dispise it. if yours isn't leaking now just hold on a second it will be. they didn't drive good when they were new and it was downhill from there.
Check out the Benchworks kit. it's not cheap but it was worth every cent. easy installation , no leaks and you'll have a high boy that drives better than any ever did off the showroom floor.
I've messed with this abortion of a steering set up my whole life and I've grown to dispise it. if yours isn't leaking now just hold on a second it will be. they didn't drive good when they were new and it was downhill from there.
Check out the Benchworks kit. it's not cheap but it was worth every cent. easy installation , no leaks and you'll have a high boy that drives better than any ever did off the showroom floor.
5th Wheeling
Joined: Jan 2024
Posts: 46
Likes: 2
hey all
Problem:
Anytime I rotate the tires (standing still, while moving, doesnt matter) the front tires start to shake. The shake is rather aggressive.
Notes:
The truck seems to be equipped with a bendix power assist setup and ive noticed while I rotate the wheel the return line seems to be collapsing near the PS.
Shop said they bled the system as well.
Does anyone know what could be causing this?
Problem:
Anytime I rotate the tires (standing still, while moving, doesnt matter) the front tires start to shake. The shake is rather aggressive.
Notes:
The truck seems to be equipped with a bendix power assist setup and ive noticed while I rotate the wheel the return line seems to be collapsing near the PS.
Shop said they bled the system as well.
Does anyone know what could be causing this?
Lead Driver
Joined: Oct 2018
Posts: 7,847
Likes: 2,353
By rotate the tires I assume you mean steer from side to side.
If this is the case and it's shuttering it means your steer cylinder is lacking pressure to work. this could be from a low fluid level, slipping belt on the pump or a weak pump or bypassing cylinder. faulty control valve possibly.
If this is the case and it's shuttering it means your steer cylinder is lacking pressure to work. this could be from a low fluid level, slipping belt on the pump or a weak pump or bypassing cylinder. faulty control valve possibly.