Steering sticks/stiff after ~20 minutes driving

[FlyingBear]

I've asked around on this one and gone through the threads, but is foreign to me as to the "why":

After about 20 minutes of driving, my steering progressively gets sticky/stiff. This makes any amount of wandering way worse because I find myself gripping the steering wheel in both hands just to no overcorrect what was (minutes earlier) a simple nudge of the wheel when I first started driving. It goes away once the engine has cooled completely, linearly from what I can tell.

- I've bled the system, but perhaps I should try again?
- I have replaced the water pump/power steering with a FlowKooler and Saginaw combo. They've made the first 20 minutes even better, no whining, easy enjoyable driving, but didn't fix the original problem.
- It seems it could be something to do with friction/heat as it gets worse and tapers off as it rests between drives: steering box (haven't replaced it)? Ball joints?
- I'm an amateur, so how could I check the steering box? I've seen rebuild kits etc... I learn by this forum and youtube typically.

I'd prefer to not only do 15 minute drives forever... Any ideas?

 

[DirtDonk]

Yeah, you can only get so far in 15 minutes in most places!
Not sure myself, and have never run into this issue with a new Saginaw type pump either. So following along to see what others say.

I would have thought deteriorating old fluid too, but not after bleeding and new components have likely replaced 100% of the old stuff anyway.
You are using real power steering fluid, correct? Not just transmission fluid?
I would assume a "cheap" fluid might act up when hot, but I've never seen even a cheap oil/lubricant that was not up to the basic tasks.

Belt slipping? Is it a serpentine or a v-belt system?

Paul

 

[blubuckaroo]

According to the shop that rebuilt my steering box, it can take quite a few lock-to lock cycles to work all the air out.
I put it up on jack stands and cycled the heck out of it.
Another thing comes to mind though. Centering the pitman arm within the box's limits is really important.

 

[SteveL]

What size tires? Hydroboost brakes? Lines or pump real close to header? Just spitballing things that might be heating up the fluid.

 

[Viperwolf1]

I'm going with a loose belt.

 

[DewyDag]

Gear adjustment to tight on the steering box? When it heats up and expands the steering gears binding?
Just a Thought. I have overtightened them before.

 

[Broncobowsher]

IF you remember back in the 90s a LOT of cars suffered morning sickness in the steering rack. The steering would be spotty until it warmed up. While this is different, it is the same. As in the problem changes as it warms up. And you are dealing with a steering gear and not rack and pinion. The pump already replaced pretty much rules that side out. The belt had to be re-tensioned during the pump, so that rules that out as well. At this point I am going to say there is a problem with the seals inside the steering gear. There really isn't anything else that hasn't been touched. And the seals are about the only thing left that would be temperature sensitive.

 

[Jfryjfry]

You can have your steering box rebuilt as it sounds like that is the problem. But ps systems are finicky and if there is debris in there, it is usually best to replace everything as it will contaminate the new pieces if you just replace one piece.

 

[SteveL]

I just redid my ps plumbing for hydroboost. While I was in there I added the bc ps fluid filter. Nice way to add some fluid capacity.

 

[FlyingBear]

Ok awesome, thank you all very much for the comments - couple updates and answers to your questions:

- V-belt
- Belts seem tight enough, didn’t see any slippage (thought I would have preferred that fix).
- All hoses are away from the headers, though I still think heat is an issue somehow.
- 2.5” suspension lift, 0 BL, 33” tires. To reiterate, newish sag steering pump and water pump, untouched steering gearbox.
- Fluid is decent power steering fluid, over filled if anything.
- I re-bled the system about 100 turns total.
- The videos below show the turns during bleeding about halfway through.
- It began to get “sticky” again towards the end as it heated up (idling vs driving took longer). The engines temp is fine, holding about 200 degrees, and the number of turns didn’t seem to phase it. It seemed more about length of time the engine was running and the temperature of the other components under the hood.
- I noticed something as I was pulling it back in the garage: the stickiness is due to the lack of play. When I first start it, like any car, the steering wheel will wiggle slightly back and forth and the steering is normal. After running it for 20-30 minutes, the play is gone completely, though actually turning the Bronco isn’t difficult. So: it seems like the pump is working, but something is not allowing the initial freedom of movement of the wheel.
- SO (to narrow it down): As it heats up from driving, what would bind the initial play in the steering wheel?

Apologies if that is confusing… I’m trying to make sense of it. Videos below:

Under the hood:
https://youtu.be/c_4xs4nyigQ

Under the truck:
https://youtu.be/PQjL7erBP0Y

Steering wheel sticks:
https://youtu.be/xCuTPuIv9xg

 

[DirtDonk]

Haven't seen the videos yet, but that sounds like what someone suggested that the gearbox preload is too tight and after heat expands things slightly it's binding up inside.

Because the box is older it might be anything, but you might consider going through the preload adjusting procedure as described in the book. Member Steve83 here has it documented on his SuperMotors pages as well.

If it was me though (and you didn't hear it from me!) I would test the theory right away and simply get under there, loosen the lock nut, turn the screw counter-clockwise 1/4 turn, tighten it back up and drive it to see what happens.
The worst you can do by loosening it (I believe) is to make the steering loosey goosey and wandery, but it should not harm anything.

In fact, the PO probably turned it tighter to try to tighten up a worn out box anyway. Not realizing you can't just do that without care and not possibly have trouble.

Viper here rebuilds these boxes for fun and local folks and has done quite a few, so knows what all goes on inside them. I don't, but that sounds plausible to me.

Good luck. Good clue tracking too by the way!

Paul

 

[Justafordguy]

I bet DirtDonk is right, the PO probably over tightened it. Just back it off a 1/4 turn, drive it and see if it gets any better, repeat. If it gets better then go through the proper procedure and re-adjust it.

 

[FlyingBear]

Welp... i bet you guys are correct - the preload allen head is stripped - grrr.

This PO guy sounds like a real jerk (what is a PO?)

 

[DirtDonk]

PO equals the dreaded "previous owner" and most of our rigs had them unfortunately.
We just hope that someday we don't earn that name!

Paul

 

[DirtDonk]

Oh, and most Bronco PO's seem to have considered themselves "wiring experts" judging by the condition of our wiring harnesses!%)

Paul

 

[oldiron]

oh, and most bronco po's seem to have considered themselves "wiring experts" judging by the condition of our wiring harnesses!%)

paul

amen!!!!!