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2500HD/3500 HD Trucks & Drivetrain Discussion Forum for the 2001 & newer 2500HD/3500 Trucks, Transmissions & Drivetrain

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  #11  
Old 05-31-2017, 09:42 AM
Kennedy Kennedy is offline
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Yes the pitman arm does the work, and takes the main load of steering, but there is another factor. The twisting thrust load.

The drag link is offset _____--------------------_____

This offset causes input from the wheels/tie rods to put a twisting force on the drag link. This is particularly obvious in 4x4 (truck pulling) where the front tires try to toe in under power. To test this with both wheels off the ground take a pipe wrench and grab the drag link and attempt to rotate it. As you rotate it (which it should NOT) you'll see the toe changes quite dramatically.

The other test is to jack just the RF wheel off the ground and grab the wheel at 3 and 9 and try to steer it.

In Gary's case because the pitman was replaced all may seem tight as it is difficult to reproduce road forces, but trust me, the PISK that I linked above will make the steering MUCH more precise and hold toe more consistent.



Both arms attach to the same rigid drag link. Replacing one will give you the sense that the other is OK when it is not
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2002 Chev K2500HD D/A CC Long LT 11.77@ 124mph at 7700# fuel only-e.t. needs help
2005 Chev K3500SRW D/A CC Long LT(SOLD)
2007 Chev K2500 Classic EC Short LT (Sold)
2012 GMC K3500SRW D/A CC Long LTZ Happy Birthday to me! Built 1 working day after my birthday and delivered 7 days later.
2016 GMC K3500SRW D/A CC short LTZ

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  #12  
Old 05-31-2017, 09:49 AM
rapidoxidationman rapidoxidationman is online now
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Thanks for the education
The more you know...
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  #13  
Old 06-01-2017, 04:09 AM
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EdHale EdHale is offline
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Quote:
Originally Posted by gary_lucas View Post
Yah, I'm not sure what to say.

There's literally no obvious play in the pitman arm, there was with the Idler.

I'm still going to swap it out, just in the fall. At this stage i've spent about as much as I can swing on it and I definitely need to address the leaking power steering fluid (as far as I can tell that's coming from the power steering pump). When I say leak I mean the return line is slightly dirty and damp, it's not pissing out or anything. I haven't seen low power steering fluid.

I'll pull it apart in the fall and address it all and throw on the cognito braces.

I appreciate everyones input and will re-check the pitman again this weekend!



G
I just had a leaking hydraulic hose replaced from the power steering pump to the brake booster. Both were leaking just enough to cause a dirty/damp look around the leak, but the damp was getting damper. That booster is expensive!
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  #14  
Old 06-01-2017, 09:51 PM
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gary_lucas gary_lucas is offline
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Interesting, I'll test that (Pipe Wrench) out in the next week or so. Certainly before putting the 5th wheel on.

I'm really trying to hold off on more expenditures at this stage. I've poured almost 10k into this truck between the head gaskets, brakes, front end work fluids etc. That includes buying all the tools (until recently I lived in a condo... working on my own vehicles has been a no go for a long time now).

In an ideal world I'd like to soak up a few months of usefulness before hammering another pile of cash into the problems. I'm suspecting that given my other issues my steering gear is on the way out as well + when I do that I'd want to do at least some of my power steering lines. So I'm hoping to wait until the fall or next spring for those items. Given that the cognito kit is a bolt on I could do that in the fall.

It seems to me that I really want to avoid cracking that area (Pitman, gear, PS components) etc until I'm comfortable doing them all...

G

Quote:
Originally Posted by Kennedy View Post
Yes the pitman arm does the work, and takes the main load of steering, but there is another factor. The twisting thrust load.

The drag link is offset _____--------------------_____

This offset causes input from the wheels/tie rods to put a twisting force on the drag link. This is particularly obvious in 4x4 (truck pulling) where the front tires try to toe in under power. To test this with both wheels off the ground take a pipe wrench and grab the drag link and attempt to rotate it. As you rotate it (which it should NOT) you'll see the toe changes quite dramatically.

The other test is to jack just the RF wheel off the ground and grab the wheel at 3 and 9 and try to steer it.

In Gary's case because the pitman was replaced all may seem tight as it is difficult to reproduce road forces, but trust me, the PISK that I linked above will make the steering MUCH more precise and hold toe more consistent.



Both arms attach to the same rigid drag link. Replacing one will give you the sense that the other is OK when it is not
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  #15  
Old 06-06-2017, 12:54 PM
Kennedy Kennedy is offline
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With a fresh idler arm I doubt you will see much as any one of these joints in fresh condition resists rotation pretty well. Put a few miles on and it will loosen up especially with a partly worn pitman on the other end.
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More than just a salesman-I use and test the products that I sell on a daily basis!
Superflow Lie Detector in house
2002 Chev K2500HD D/A CC Long LT 11.77@ 124mph at 7700# fuel only-e.t. needs help
2005 Chev K3500SRW D/A CC Long LT(SOLD)
2007 Chev K2500 Classic EC Short LT (Sold)
2012 GMC K3500SRW D/A CC Long LTZ Happy Birthday to me! Built 1 working day after my birthday and delivered 7 days later.
2016 GMC K3500SRW D/A CC short LTZ

Custom tuning in house using EFI Live tuning software!
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  #16  
Old 06-09-2017, 09:19 PM
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gary_lucas gary_lucas is offline
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From what Iv'e read / researched it's not easy to get the pitman arm on / off without removing the steering gear. So even if I wanted to do it now I'd be in for a 'big' job. Or is something that's really not that big of a deal, I also don't know if my gear is a 3 spline or 4 spline which is a PITA as it means I need to do a bunch of work just to find out.
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  #17  
Old 07-03-2017, 09:10 PM
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gary_lucas gary_lucas is offline
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So took it out with the trailer. There's still some slop in the steering, about 1/2 as much as there was previously.

I'm probably going to do the pitman arm next. My main frustration is I'm pretty sure the steering gear needs replacement and ideally I'd like to do them both at the same time...

Need to do some research, if I'm going to replace the steering gear I want to make sure the unit I replace it with is better than the one being replaced. I assume I can confirm that on a bench.

Do people just put up with slop? or is it something that can be fixed and stay fixed? IE with the support braces?
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  #18  
Old 07-07-2017, 11:01 AM
Big Green Big Green is offline
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alignment can affect steering with a load significantly. Talk to your shop.

I had mine aligned and it drove great until I put a trailer behind it. Then it was a 2 handed job to keep on the road at 65mph. The back of the truck lower under load had a big affect on caster ( I think) and if it's near the limit they can get hard to drive.

Big Green
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  #19  
Old 07-07-2017, 01:15 PM
Kennedy Kennedy is offline
Long Distance Crew Chief for BMDMAX
 
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Quote:
Originally Posted by gary_lucas View Post
So took it out with the trailer. There's still some slop in the steering, about 1/2 as much as there was previously.

I'm probably going to do the pitman arm next. My main frustration is I'm pretty sure the steering gear needs replacement and ideally I'd like to do them both at the same time...

Need to do some research, if I'm going to replace the steering gear I want to make sure the unit I replace it with is better than the one being replaced. I assume I can confirm that on a bench.

Do people just put up with slop? or is it something that can be fixed and stay fixed? IE with the support braces?

In my experience, the steering slop is pretty much non existent with fresh pitman and idlers plus the braces. I stick with OE joints for these.
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Kennedy Diesel-owner
More than just a salesman-I use and test the products that I sell on a daily basis!
Superflow Lie Detector in house
2002 Chev K2500HD D/A CC Long LT 11.77@ 124mph at 7700# fuel only-e.t. needs help
2005 Chev K3500SRW D/A CC Long LT(SOLD)
2007 Chev K2500 Classic EC Short LT (Sold)
2012 GMC K3500SRW D/A CC Long LTZ Happy Birthday to me! Built 1 working day after my birthday and delivered 7 days later.
2016 GMC K3500SRW D/A CC short LTZ

Custom tuning in house using EFI Live tuning software!
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  #20  
Old 08-04-2017, 10:47 PM
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gary_lucas gary_lucas is offline
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Got in there today.

The pitman had a bit of wear on it, but not bad.

I put my hand on the steering shaft input to the steering gear.

Other hand on the pitman arm... Had someone rock the wheel. Like this: https://goo.gl/photos/MT6CgC6eS37ewMqy8

No movement felt at the pitman arm. I think the steering gear is cooked, bought a rebuild... Put it back together... Stripped the hydroboost -> steering gear bolt... (Swore allot...)... Bought a new power steering line...

Installed it, was much... Much more carefull with the other line and got it in...

Couldn't tighten up the pitman arm... Got it just enough that I could get it out of the garage...

Realized that I am retarded while cleaning up and that I just needed channel-locks on the bottom of the stud (facepalm)...

Will fix that up tomorow. Not sure if the steering is tight yet...

I have the cognito kit and will install that soonish, the day was so long I gave up on it for today.

Wish me luck!
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