fighting a steering problem i cant find

[dusterbd13]

Exactly my thoughts too when I read that.

As far as the wandering, are the 'techs' setting the front end up as according to stock specs?
Stock spec leaves a lot to be desired. Throw in a bunch of mods & some compensation needs to dialed in.
With wider, heavier wheels & tires, these trucks need as much positive castor dialed-in as possible. Setting it up as such will make the truck want to come back to center more readily. This will also give the steering a somewhat heavier feel which will kinda-sorta overcome these truck's over-boosted power steering systems.
Have the camber knock-outs been punched? If not, then the tires are actually riding on their outer edges, leading to that twitchy wandering.
Wider/heavier than stock wheels & tires require a bit more toe-in. When a vehicle is having it's front-end aligned, sitting on the alignment rack, it's actually out of alignment. It's not till it's rolling that it comes into spec. This is due to the drag that the road puts on the components. Adding wider/heavier wheels & that drag is greater than the factory sized T's-n-W's create, consequently pulling the alignment outa whack.

The techs have been using the factory specs. Knockouts were punched out.

What is the preferred spec for these with wide rubber and lowered? My normal muscle car standards are -1.0 camber, 5.5+ caster, 0 toe. However, thats on muscle era mopar and chevy cars. So , completely different application .

Could the majority of the problem be alignment specs and steering box adjustment at this point?

Dad drove it today. He had a different way to describe the steering feel: lots of effort to start the turn, gets easier off center. Easy to steer till close to center, then stiff and difficult. Almost like the middle 6 inches of steering wheel travel (3 inches either way from center) have no assisst or major bind, then the power steering comes back.

Makes sense that way. Exactly what ive been experiencing just a different way to describe the issue.

 

[delta_p]

Could the majority of the problem be alignment specs and steering box adjustment at this point?

That's what your Dad's description sounds like.

 

[someotherguy]

I understand your concern completely. Scrub line on these would be dangerously unsafe with anything smaller than 18s. With an 18-inch wheel I have roughly 3 in between the lowest point of the control arm and the dirt on a bare steel wheel. I have admittedly given thought to going back to stock control arms and shorter Springs so I can run 15in Wheels safely. However that's a decision for after it's fixed.

Not to sidetrack too much but the clearance to the wheel is one issue, the real one though is lca clearance to the ground, speed bumps, dips or debris in the road, etc.

Good luck as it sounds like you're on the right path, stock alingment specs are not sufficient for a lowered gmt400 and the steering box adjustment is a lot more involved than just turning the screw on top - don't get lazy on that or it will cause you problems.

Richard

 

[dusterbd13]

Care to link me to the second adjustment procedure all i can find is the top nut method for the worm gear.

And scrub line: i measured on bare steel wheels, weight on the suspension. The wheel has to dig into the dirt 3 inches before control arm contact. However, thats on 18s.

 

[someotherguy]

Sure - these are some sketchy but totally legible pics of the 1994 GM C/K factory service manual, regarding the steering box adjustment - sorry couldn't get really clean scans; these are really thick manuals and I didn't want to destroy them trying to lay them flat on the scanner.

http://www.someotherplace.com/info/FSM3B_10.JPG

http://www.someotherplace.com/info/FSM3B_11.JPG

Richard

 

[dusterbd13]

k, so i want to confirm my thoughts. I have this thing gutted like a trout right now.

1. Steering is isolated from the spindles via outer tie rods bein disconnected. The steering has about tge same effort running as not at idle. Its slightly easier running, but still requires not insignificant effort. Definitely not 1 finger effort. More like a manual steering box at parking lot speed. My thought is bad pump. Any way to confirm?

2. Lower ball joints shouldn't require massive effort to move in any direction, and DEFINITELY should not feel notchy or incredibly much stiffer past tge central point of range, correct? Its much easier to move towards droop than compression, and much easier fore/aft than droop OR compression.



So, i think its bad lower ball joints, and a bad pump. But want to make damn certain this time.

 

[delta_p]

what about when you rev it up? FWI on my '96 C1500 it's never been one finger easy turning. And i have been know to swear my power steering is out but it's always after i drive my 2017 Civic daily driver for a week and then drive the truck. When i broke a belt once and had to get it home stop and start without over heating, I had to get up on that dang steering wheel, and there was no question power steering was out.

Just keep in mind it won't go to full pressure because either the valve will open or it's stuck and restricted but the pressure should be higher than at idle.

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A power steering and rack pressure test kit is really the proper way to diagnose.

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[dusterbd13]

Revving it makes a slight difference in the amount of effort . And i am comparing it to an over boosted neon....

Maybe stop at ball joints and see?

 

[Lu Blunt]

Any luck on your steering issue? It sounds identical to the problem I’m having.
https://www.gmt400.com/threads/memory-steering.43600/page-2#post-1029615

 

[sparetimefab]

So I am having the same issue. 99 suburban, djm uppers and lowers, 1 drop spring. New steering box, all new linkage, and new lower shaft. It has been aligned twiceand it seems to be getting worse. Because we all have the djm arms makes me think maybe they are causing the issue.

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