Sticky or stiff or sticking steering (solved)

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Cowtc, Jul 5, 2015.

  1. Cowtc

    Cowtc New Member

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    My prius had developed sticky steering, where most noticeable on the motorway, you normally make small steering adjustments to keep in lane. The steering wheel would stick and I'd have to push it back manually to centre it again. This would only happen on small turns of the steering wheel.

    I solved this issue by taking it to a local garage who greased the steering rack (where it can be greased), it's been 4 months and I've not had the sticky steering issue since.
     
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  2. Cowtc

    Cowtc New Member

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    I should probably add that before new greasing, as much of the old grease was removed as possible
     
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  3. Athos

    Athos New Member

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    Thanks for your post @Cowtc . I have the same issue on my 2008. Tires fine, alignment just done. The steering is fine and light but in a straight line it sticks so you have to make constant adjustments. On a very slight curve the car will continue the turn if you let go of the wheel. It doesn't want to re-centre. It is the same in both directions. I want to call it stiction, like a computer hard drive that won't start spinning unless you shake it.

    I tried new Mevotech shock tower bearings, still stiff. I then regreased the old ones and went back to them. No change.
    With the car raised I disconnected the tie rod ends and checked for stiffness of the shock tower by turning the steering knuckle by hand. It was smooth and easy to rotate. No stiction.

    I disconnected the steering shaft and compared the turning effort of the steering column with a 2005 parts car. Overcoming the initial stiction was about the same for both.

    I compared the turning torque on the rack with the rack of the parts car and it took 4 more inch pounds to overcome the stiction: 26 inch pounds for the parts car and 30 inch pounds for my 2008. (I controlled for friction of the tie rod ends dragging on the subframe by supporting them to make movement frictionless.)

    Does anyone know the torque required to start the rack shaft turning? Has anyone ever regreased the rack? I doesn't look easy, especially with the large 12 point female plug. Torque values would be important or maybe you could do it by feel. What grease would be best?

    I could simply go to a wrecker and get a new rack but the two torque measurements I took seem close and maybe the rack is not the problem.

    Any suggestions would be welcome. Thanks everyone.

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    #3 Athos, Oct 14, 2019
    Last edited: Oct 14, 2019
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  4. edthefox5

    edthefox5 Senior Member

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    ,are you aware there was a tsb offered about 10 years ago for a steering intermediate link that could fail or bind the steering? It was a big deal nationwide recall.

    It was the same time they offered to chop the bottom of the gas pedal off to prevent runaway Prius from jammed floor mat.

    There’s not much to grease steering rack wise unless the rubber boot failed failed there’s 2. Previous poster did a nice job checking the strut steer bearing they fail. But be aware you tested that bearing unloaded with no weight on them. There is tremendous weight on those bearings the entire front end.

    I had my struts replaced at 100k miles and the steer bearing too and got 100% easier steering effort. Major improvement. If you have 150k miles or more I would buy new struts and steering bearing. They are a maintenance part. The factory struts only last like 80 to 100k.
     
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  5. Athos

    Athos New Member

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    Here is a follow up on my steering rack adjustment.

    It worked! Steering is light now with little to no stiction. I loosened the large plug that holds the rack against the worm gear. I also had a bit of a dead spot at the gears. It might have been the rack but I decided to swap the worm (pinion?) gear because I didn't want to remove an inner tie rod to get at the rack. That seemed to solve it. I didn't regrease because the grease looked fresh. It had a jet-black grease that was probably lithium based and I didn't want to chance it with what might be a lesser quality grease.

    I didn't have a 12 point torx that big so I used a 15/16" nut and a 15/16" socket. That worked. It was not too tight and came off fairly easily with the rack in a vice to hold it. It looked like they used a grey coloured gasket goo so I reassembled it using Hondabond (same colour and texture when cured).

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  6. Athos

    Athos New Member

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    Another follow up.

    Working great. I was on the highway and the car had fingertip steering. It was a night and day difference. I caught myself going 125kph which I would never have done before when it was sticky.

    For anyone who has the rack out or had dropped the cradle I highly recommend that you at least check the stiffness. Grab one of the tie rods then push and pull it. If it is sticky or notchy just loosen off that adjuster. You will probably have to completely remove the plug to clean up the threads so you can make fine adjustments. Use gasket goo on the locking nut to seal it.

    There is a spring behind the adjuster plug which you shouldn't allow to drop, roll and hide in the corner of your garage under a heap of fossilized valuables but nothing about the job is really hard once the rack is out. I tried measuring the torque needed to overcome the stiction but you don't have to go that far. Besides, my torque wrench was at the bottom of its range and probably wasn't accurate at all. Just adjust it until the rack slides smoothly in the housing. Think like Goldilocks.
     
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