Rack & Pinion or Power Steering Pump

Your opinion?
Steering is excessively stiff when vehicle is cold, loosens up when ambient temps are warmer. When I say "cold", I'm referring to between +10 degrees and -20. Those are the typical morning temps here now for the next few months.
I'm about to start playing parts-darts and hoping to hit a bullseye on the first toss. My first thoughts are either the PS pump or the rack beginning to fail. I'm not getting a single chirp from the pump so leaning toward the rack. Both appear to be original with 350k miles.
Which dart would you toss first?

 

Check for leaks coming from rack, hoses or pump. If nothings leaking or making noise, I’d start by flushing the PS fluid. Use a turkey blaster or a smaller hose transfer pump to suck out the atf from the reservoir and refill. Turn wheels from side to side to get most of the fluid circulated.

 

If the rack isn’t leaking, then why replace?

Those temps you have are enough to lower the fluid viscosity and make a stiff wheel. Hows the wheel feel once the fluid warms?

How fresh is your fluid? Using Dex/Merc as spec’d?


The PS Pump has these inner ‘veins’ that look like shim paddles from diagrams. Maybe those are worn out reducing the fluid ‘push’ which is causing the stiff wheel.

A couple years ago I did a dumb Hand Model move and sucked and filled the rez with the engine ON. Got to the bottom of the rez and the PS Pump started screaming. Fortunately, my Golden Hands reacted quickly to the stand by fresh Dex/Merc quart next to me. I poured the fluid in and then some Boogers showed up after the scream immediately stopped. The Steering has felt better since. I do not recco procedure this to anyone. Pictured is about a third of the removed soft in nature Boogers. Where did the Boogers come from? Why did they form? What did they cause? Lots of questions.

BTW, I’ve always had a slight leak at my rack bellows for a few years. Mostly, the driver side which does not affect the rez fluid level. I haven’t seen any pass side drops in 6 months.

Conclusion: If you have the money, I’d replace the entire system (Pump, All Hoses, and OEM New Rack... not rebuilt) which will ensure a clean one time fixes it all repair.

 

Thank you for the reply (Casper). I'm a little ahead of you there. I replaced the PS reservoir (was leaking) about a month ago and bled the system properly at that time. The problem was occurring prior to that and did not change at all afterward. It's not air in the lines.

 

Where was the leak on the rez?

 

It gets better once the fluid warms up but not as free as it should be. If it's cold all day, it stays stiff. My neighbors with Toyota trucks don't have any issues and I've never had this issue with another vehicle up here.

 

I thought it was the res itself but it was the return line... also replaced that.

 

Yeah. I fixed that one on mine with a snake clamp on both in and outs. Just put one on my PS Pump inlet when I jangled the Mojo during the TBelt Replace.

 

I just texted the original owner to ask if either had ever been replaced... we'll see what he has to say soon. That might shed some light. I know he was having the problem when he gave it to me. He had gotten an estimate from BrakesPlus. Of course they wanted to rebuild the entire steering system (liability bullshit) at a cost of over $3K. Umm....... NO.

 

well, maybe not soon... forgot he went ice fishing today... in his NEW Tundra

 

This would be so much easier for me to diagnose if Toyota had used a solid axle front instead of this dbl wishbone and rack system.... their target demographic was probably not offroad enthusiasts.

 

But the steering with rack and pinion is so smoove and direct. Good design. They do make some "cold weather" power steering fluid formulations. Normal PS fluid can turn to sludge or even freeze at low temps. Trying a colder formulation may be worth it before spending all the money on a pump or rack, especially since it improves once warm.

 

It seems like something is going on with it. If it was just cold weather alone wouldn't you experience it with other vehicles? You said your other cars and your neighbors don't have this issue.

That member in the other thread solved this issue by greasing the U joint on the steering shaft.

https://www.tundras.com/threads/power-steering-too-stiff.78607/#post-2009438

 

KNABORES - I think I will try your suggestion, can't hurt! Although this was noticeable even before the really cold temps hit. FirstGenVol - First effort will be to lube the steering shaft as discussed in that thread.

 

It seems like that makes it even more likely it isn't the cold weather causing it. It's probably just making it worse. I would do what others suggested and make sure you get fresh fluid in there too.

 

Correct. Something is definitely not right.

 

When my transmission is cold, it has a mild 1-2 shift hiccup. My steering is a little stiff when i first get in regardless of temp too. Possibly something getting worn out. The transmission has behaved this way for over 50k miles, still going. The steering rack has behaved this way for over 25k miles. Still going. I'll keep changing the fluids and until they start leaking severely or show signs of impending doom, I'll keep servicing them and rolling along. Get my money's worth.

 

Cold weather not "causing" it so much as really amplifying it.

 

Transmission is performing flawlessly.

 

yes, wonderful design... for the highway. My Jeep is not as nice as this on the hwy but the axles will articulate enough to crawl over the Tundra.

 

Yeah buddy. Looking forward to the u-joint lube feedback.

 

I'm probably gonna reach up in there with my hand and slather it in. Any advice on how to best protect my hands?

 

Looks like a dangerous job. I’d go for a heavy protection type glove.

 

In just out of curiosity

I did have an xterra that was impossible to turn the wheels on when it was cold. Mainly my fault, the truck had no power steering fluid, ran strictly Lucas stop leak. The steering box is a weak point on those trucks with bigger tires. I have since learned that this was a bad idea. I don’t recommend it . Dumb Sh*t you did in high school lol

 

Roger that PHM, thank you.

 

Conclusion: It was the power steering pump.
The belt finally started talking. Slight chirps occasionally when making a slow speed turn at moderate radius.... that was the eventual giveaway.
I replaced the pump with a new Cardone from rockauto and viola, no more stiff steering at all. Driving it for about a month since replacement and still perfect steering.
Thanks everyone for your insight!

 

^^ This too. ^^ I did a complete flush and bleed after replacing the pump.

 

My truck does the same thing. Good to know what you did to fix yours!