Stiff Steering After Pitman/Idler/Box; 2WD vs. 4WD Steering Pump Difference?

[wildcatgoal]

I got a 2002 Tahoe LT for $2K with 191K miles. It's never left Georgia, completely rust free everywhere. Unfortunately, nobody maintained the suspension bits, so I had to replace all of that - was original. Then I started noticing the steering wheel clunk/rattle, so I replaced that plastic bearing (did nothing), replaced the upper intermediate shaft (did nothing), and finally got smart and went under the car to find the steering box had 1/4"+ of vertical/up/down play in the sector shaft, so I replaced that (did nothing). And since I was down there, I decided to replace the pitman arm, idler arm, and idler bracket (made things worse).

Now my steering is extremely stiff. Yes, I know how and did bleed the steering system.

The idler arm bracket (I decided to get Proforged parts for steering) is so extremely freaking stiff that I I had to use my entire body to move the idler arm to position it for re-installation on the drag link. The factory idler bracket pivots easily but with no play whatsoever. I don't see a reason why the idler arm bracket (which the idler arm pivots on) needs to be THAT STIFF. But at the same time, I've always hear more from the power steering pump (also original) than I thought was "normal" (but after the fluid flush it was much quieter, if not back to normal). I guess I'm thinking maybe I could use a power steering pump?

So I get to looking and see there's a different P/N for 2WD and 4WD pumps. I don't have hydroboost, so I did more research into what the difference is and all I can tell is that the 2WD pumps come with a little valve on the back such that the pressure line connects directly to the back of the pump (hence a different pressure line P/N for 2WD trucks) and the 4WD has that variable power assist steering (like mine does) and therefore you'd transfer over that nonsense to the 4WD pump (and the 4WD pumps are cheaper).

But is there actually any difference in the mechanical operation or assist of a 2WD vs 4WD pump? If not, I figure I'll just get a 2WD pump, use a 2WD power steering pressure line, and bypass that stupid assisted steering band-aid BS GM decided to add to a power steering pump from the bloody 60's. And then I don't have to use that ultra-expensive GM U-tube part that's just bound to come loose and leak since it's not supported by anything.

 

[OR VietVet]

That idler arm bracket is greaseable, did you grease it and all other greaseable steering and suspension components while under there? You should if you did not and if you do grease you should elevate the tires off the ground and turn slowly while greasing any steering components.

You said you know how to bleed the power steering system after gear box replacement. Please detail here how you did it. You may well know how but there have been many times here when a member is asking about a problem and they answer to the affirmative when asked if they did some thing right and when details come out, they actually did not do it right. Don't be butt hurt about me asking but I ran shops and saw the bleed process done wrong many times by techs that thought they knew. I ask questions, lots of them. It does not mean I don't believe someone.

By the way, it is normal to flush out or change the power steering fluid on a maintenance program. That fluid goes thru many cycles of building heat and will break down that fluid over time.

As far as installing a 2wd pump instead of a 4wd pump, your call. You experimented with the idler arm bracket and that may well be your stiff/steering wheel not returning problem. If you install what was not meant to work with your existing system, then that is on you of course. Others here will chime in and tell me if I am full of it or agree with me.

Grease the snot out of the steering and suspension components and lift and turn at the same time.

 

[wildcatgoal]

I did grease those components and regreased after bleeding the steering system (thus cycling those joints) and they're all good and greased up! Literally everything has been regreased that can be and needs to be greased under that car. All the suspension parts down the the shocks and the little camber/castor alignment bracket guide pins are now new, so... nothing should be binding due to a lack of grease.

The idler arm bracket was not an experiment, although it's turning out to be one. It was a part designed for the car. The Proforged parts I got are the same (as far as I can tell) as the MOOG parts, which I've verified with measurements of the pitman arm sector shaft hole diameter (which is too small compared to AC Delco but the same between MOOG and Proforged, telling me they get the same casting) and using a beam torque wrench on the idler arm and steering box to see how stiff the Proforged vs. MOOG vs. AD Delco idler arm bracket rotation is - Proforged and MOOG are effectively the same (almost 3x the rotation resistance as the steering box which seems wholly unnecessary) and the AC Delco is much easier to rotate (being about the same resistance to rotate as the steering box, which makes a lot of sense). I'm taking these Proforged parts off and returning them (hopefully getting a full refund; this is what Proforged told me to do and cared not about what I found). I'm installing all the AC Delco stuff as soon as the actual idler arm from them arrives in the mail. That'll be tomorrow. Hopefully these replacements fix it.

As for bleeding the system, as I have always done on mechanical power steering systems that do not have a computer-controlled bleeding process, I lift the front of the vehicle off the ground, vehicle off, and rotate the steering wheel lock to lock probably 20 times at a consistent slower pace. I then start the car and within a second or two shut it off. All the time checking the fluid level such that no air is introduced. Prior to this, I bleed the entire system by removing the return line and capping the reservoir and draining the return line until the fluid is clear. I also have an in-line Magnefine filter which, being on the return line, would not impede power steering flow in any way (and it doesn't... I already tried removing it to see if that's the issue).

 

[OR VietVet]

I agree with the power steering bleed process you do. I always lift as well. I had techs that wanted to leave the weight on the ground and I told them no way. At the very end when the lifted process is done, fine. Plus recheck fluid level after a road test. Bet that different bracket does the trick. Good luck and post here after to let us know.

 

[mattbta]

Did you take the center link completely off at any point in swapping out the idler/pitman?

 

[OR VietVet]

Did you take the center link completely off at any point in swapping out the idler/pitman?

I know where this is going.

 

[wildcatgoal]

Did you take the center link completely off at any point in swapping out the idler/pitman?

Nope. Did one side at a time plus it was always connected to the tie rods.

 

[wildcatgoal]

So I just finished replacing the Proforged idler bracket and idler arm with AC Delco Professional. Stiff steering completely solved and power steering pump no longer making any noise doing it's job. I have left the Proforged pitman arm on right now, but it'll get replaced with an AC Delco next week when I get a new sector shaft dust seal in the mail (the one off of my old steering box was covered in crap and since I found the P/N for it, I got a new one so everything is fresh and clean, haha). Great news -- my steering doesn't have the Corona.

 

[OR VietVet]

Glad it all worked out. Yea, the p/s pump works hard enough as it is without a steering component pushing back against it. Thanks for posting the fix.

 

[treehan77]

Can you tell me the part ac delco #s you used : idler, idler bracket, pitman