Thread summary
Issue:
Steering wheel randomly locked up during long drive. Power assist was degraded at the time.
Factors leading up to cause:
Poor fitting universal steering boots/bellows were used for an experimental heim joint tie rod setup. Boots did not adequately fit or seal the steering rack from the elements. Additionally, tears in the boots were formed and dirt/debris/water was allowed to enter.
Root cause:
Contaminated power assist mechanism dramatically increased friction and created a very gritty rotational action, similar to an extremely dirty ball bearing unit. The dirty mechanism, translated what was a small bind, into a fully locked steering input shaft(steering wheel). Due to the loss of power assist at the time, it was virtually impossible to push through the bind. Loss of assist was likely linked to water intrusion in the main control harness connector at the assist motor. Dirt was found inside the connector, while all other connectors were clean.
The temp fix to get home:
Shaking the wheel back and forth was able to kick the assist back on and push through the bind. Restarting the truck reset the power assist. It was observed that the longer steering input was not received, it increased the chances of it stopping, so a constant feed of small movements was needed to keep the assist working. Was able to drive home like that.
The actual fix:
Removing rack:
Removing rack shaft:
How to remove assist mechanism from housing:
Misc notes:
------------------------------------Original post----------------------------
Making this its own thread.
Had a rather large scare a little bit ago. Preface this by saying that my steering has been acting up since I went chasing for puddles after a rainstorm a couple weeks ago. Was on my way to the Grand Canyon, along the I-15 when the steering assist faded. Ok, not a massive deal, it usually just does that for a few degrees of wheel movement, then it's back. But this time, I tried to make a slightly larger correction and the steering completely locked up. Felt like the steering wheel lock when it's in park, but it wasn't the column lock, it was from the rack. Was able to slow down and get it to abruptly break free which made the truck swerve. Played with the wheel to see behavior and it was really notchy with a couple instances of locking. Turned the truck off, then back on 😂 and it reset. Was able to limp it home. One of the characteristics of the issue is that if you stop providing steering input for a while, it happens. So I proceeded to jiggle the wheel for a whole hour back home. The "spaghetti bowl" near downtown Vegas was extremely sketchy with the thought of my steering locking up, in the back of my head.
Luckily I was on a straightaway when it happened, or it could have been catastrophic. Rack is coming out tomorrow for examination. My hunch is that it's full of water and causing stuff to freak out. Ever since those puddles, it was loud during steering movement, almost like a gritty bearing, so water definitely got into it. I would take it to the dealer, but I have a heim inner tie rod setup with some kinda janky boots, so they would more than likely refuse warranty since I opened and modified the system. They have refused me for less. Time to learn more about the crappy steering on these trucks. Yay!
Issue:
Steering wheel randomly locked up during long drive. Power assist was degraded at the time.
Factors leading up to cause:
Poor fitting universal steering boots/bellows were used for an experimental heim joint tie rod setup. Boots did not adequately fit or seal the steering rack from the elements. Additionally, tears in the boots were formed and dirt/debris/water was allowed to enter.
Root cause:
Contaminated power assist mechanism dramatically increased friction and created a very gritty rotational action, similar to an extremely dirty ball bearing unit. The dirty mechanism, translated what was a small bind, into a fully locked steering input shaft(steering wheel). Due to the loss of power assist at the time, it was virtually impossible to push through the bind. Loss of assist was likely linked to water intrusion in the main control harness connector at the assist motor. Dirt was found inside the connector, while all other connectors were clean.
The temp fix to get home:
Shaking the wheel back and forth was able to kick the assist back on and push through the bind. Restarting the truck reset the power assist. It was observed that the longer steering input was not received, it increased the chances of it stopping, so a constant feed of small movements was needed to keep the assist working. Was able to drive home like that.
The actual fix:
- First fix attempt will be to clean all components of old grease and dirt, refill with fresh heavy duty grease and reassemble.
- Next attempt, if needed, will be to replace steering rack shaft and Electric assist mechanism (sleeve, main unit bearing and loose ball bearings).
- Last attempt will be to replace the entire rack with new ZR2 unit (PN 84670798).
- Possible assist motor replacement for ZR2: PN 84494269
- Clean all electrical connectors thoroughly and use dielectric grease to help protect connections from future water intrusion.
- Replace steering boots/bellows to achieve good fitment and sealing.
Removing rack:
- 18mm top bolts (one on each side, top of front engine crossmember)
- 13/16" lower bolts (one on each side, front face of engine crossmember)
- 7/16" input shaft bolt (must be taken completely out, steering wheel straight)
- Disconnect locker and axle disconnect connectors.
- Easier to remove two large plugs at front of engine crossmember vs plugs on assist motor.
Removing rack shaft:
- Remove dust cover/seal from input shaft
- Remove four 10mm bolts holding torque sensor cover.
- Remove cover.
- Unplug torque sensor
- Remove input shaft nut cover
- Remove input shaft retaining nut
- Tap input shaft outwards, through top of rack.
- OPTIONAL: Remove shaft preload tensioner.
- Push rack shaft towards driver's side
- Catch any loose ball bearings as the rack shaft exits the assist mechanism
- Remove all remaining ball bearings from assist mechanism (72 total)
- Remove rack shaft.
How to remove assist mechanism from housing:
- Use a drift or punch to unthread and remove locking collar.
- Grab assist pulley and pull straight out. Unit bearing is NOT a press fit. Tap housing with rubber mallet if needed.
- NOTE: there is a shim on either side of the unit bearing. (Rack housing, shim, unit bearing, shim, locking collar.) When reinstalling locking collar, collar should sit flush or slightly recessed from housing surface.
Misc notes:
- 18mm top bolts (one on each side, top of front engine crossmember)
- 13/16" lower bolts (one on each side, front face of engine crossmember)
- 7/16" input shaft bolt (must be taken completely out, steering wheel straight)
- 10mm bolts for all small fasteners on rack.
- 15/16" Input shaft cover bolt
- 17mm input shaft nut
- 46mm tensioner lock nut (1-13/16" can be used, but not ideal)
- 1" hex - tensioner bolt
------------------------------------Original post----------------------------
Making this its own thread.
Had a rather large scare a little bit ago. Preface this by saying that my steering has been acting up since I went chasing for puddles after a rainstorm a couple weeks ago. Was on my way to the Grand Canyon, along the I-15 when the steering assist faded. Ok, not a massive deal, it usually just does that for a few degrees of wheel movement, then it's back. But this time, I tried to make a slightly larger correction and the steering completely locked up. Felt like the steering wheel lock when it's in park, but it wasn't the column lock, it was from the rack. Was able to slow down and get it to abruptly break free which made the truck swerve. Played with the wheel to see behavior and it was really notchy with a couple instances of locking. Turned the truck off, then back on 😂 and it reset. Was able to limp it home. One of the characteristics of the issue is that if you stop providing steering input for a while, it happens. So I proceeded to jiggle the wheel for a whole hour back home. The "spaghetti bowl" near downtown Vegas was extremely sketchy with the thought of my steering locking up, in the back of my head.
Luckily I was on a straightaway when it happened, or it could have been catastrophic. Rack is coming out tomorrow for examination. My hunch is that it's full of water and causing stuff to freak out. Ever since those puddles, it was loud during steering movement, almost like a gritty bearing, so water definitely got into it. I would take it to the dealer, but I have a heim inner tie rod setup with some kinda janky boots, so they would more than likely refuse warranty since I opened and modified the system. They have refused me for less. Time to learn more about the crappy steering on these trucks. Yay!