Steering wheel off center after hit - damaged sector shaft? (1 Viewer)

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Was wheeling at the Mojave Road, didn't see a decent size rock and hit it pretty hard at ~10mph. Wasn't aired down, tires/wheel are fine but it was decent thump. After inspection notice one lower knuckle stud sheared off, other 3 still tight. It actually drove straight after but steering wheel off center by 45deg. I drove it out of trail and drove it on road, aside from very slight pull and steering wheel off center it actually drove relatively normal. Was able to drive it back home 200+ miles no problem.

96 LX450 125k, suspension all stock except 2.5 OME heavy lift, 33in KO2's.

Did some investigation:
- Steering wheel is 45 deg off to driver side. Aside from it being off center it drives pretty straight.
- Knuckle bolt sheared off, I was able to drill it out with arm in place, no problems. I plan to replace all 4 and perhaps rebuild knuckle
- Knuckle arm looks ok to me. I reference a couple pics online and it doesn't appear bent to me, but let me know if you think it is. See pics.
- Tie end rod and and relay rods looks straight. Tie ends have no play
- I measured the relay rod at 42.75" which from what I looked up close to spec
- The panhard bar looks ok, straight part still straight and I measure it to be 31.75" which also looks to be to spec. Bushing looks ok.
Mounts on both side looks solid.
- The pitman arm looks ok, can't imagine that can be bent
- I pulled off pitman arm to check sector spines. It looks straight to me. See pics
- I did measure if the front axle is off center. It's ~1cm shifted to driver side. Not sure if that's from the lift or increased from this incident.
- I turned steering wheel to center to see how much lateral movement at the relay bar it would translate to and it's about 1cm
- From the off center position, I turn steering wheel to dead lock on both side and it's about equal, so that tells me the steering
components after steering box is pretty much centered.

So I'm trying to figure out what's causing the steering wheel to be off 45deg. If just off a little I'd just adjust the relay bar and call it a day.
I see a good amount of discussion and concerns after trail hit twisting sector shaft so I'm concerned it's compromised.
What's confusing me is the splines looks completely straight. Is it possible for the shaft to twist further up or something inside
steering box? or some other damaged part? Want to get people thoughts before I go down the path of 105 sector shaft.

I've also read it's possible for steering shaft to skip a spline at input shaft connection. I wasn't cranking the steering wheel when it hit
so don't think there was much pressure on it. This could explain it but I find it a little hard to imagine for connection to skip a spline.

Thoughts? Thanks in advance.

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??

Thoughts?
 
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IMO the pic of the spline is inconclusive. The bar appears to be touching the spline at the bottom but not towards the top. If the very tip of the top of the bar is in fact touching the spline, and a gap exists below that, I'd call it twisted.

The sector shaft won't twist above that, the spline above the pitman arm is the weakest point by far.

I wouldn't discount the possibility that the steering arm is not mated properly though. Loosening it and replacing the studs may result in the steering wheel returning to normal. Also, the steering wheel being off-center could be the sum of several conditions- slightly twisted sector shaft, slightly twisted steering arm to knuckle interface, slightly bent steering arm, slightly bent panhard or panhard mount, or other things which each in themselves might be very difficult to ascertain.
 
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One of my 80s had an unfortunate sideways encounter with a curb at 15mph. Tracked straight but steering wheel off center. No twisted splines as far as I could tell. So I adjusted the relay rod. My axle is probably shifted slightly and that has caused the issue.
 
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IMO the pic of the spline is inconclusive. The bar appears to be touching the spline at the bottom but not towards the top. If the very tip of the top of the bar is in fact touching the spline, and a gap exists below that, I'd call it twisted.

The sector shaft won't twist above that, the spline above the pitman arm is the weakest point by far.

I wouldn't discount the possibility that the steering arm is not mated properly though. Loosening it and replacing the studs may result in the steering wheel returning to normal. Also, the steering wheel being off-center could be the sum of several conditions- slightly twisted sector shaft, slightly twisted steering arm to knuckle interface, slightly bent steering arm, slightly bent panhard or panhard mount, or other things which each in themselves might be very difficult to ascertain.
Good eye, I think you're right the splines are ever so slightly wider and minutely twisted at top.... you're convincing me to go down the 105 sector shaft rabbit hole.
Good point about steering arm shifting, I went back and checked, the crusted dirt around it does show a hairline so it move to pop off the bolt, but no gap to suggest any displacement. I also check the hole of the missing stud and the threaded hole is centered so not much movement if any.
Yes definitely possibly everything has moved a little, but I figure to have 45 deg off something must have suffer some damage that needs to be addressed. I'm leaning towards the sector arm.

Thanks for your insight.
 

baldilocks

Battle Ground, WA
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This same thing has happed on both 80’s I’ve owned and to others I’ve wheeled with. Nothing conclusive has ever come from very thorough inspections of everything that makes up the steering and suspension up front in my case. Nor have I ever twisted splines. It is what it is. Usually a small adjustment of the drag link solves the issue as long as a misaligned steering wheel is the only problem. I see no need to over think it and sector shaft splines should not need to be inspected with a laser. Keep that pitman arm retention nut torqued. It’s on my pre-run check list.

The broken sector shaft hysteria is just that, over blown hysteria. I’ve ran Saginaw boxes on other 4x4 vehicles that I bounced off rocks and never broke a sector shaft on those and 80 steering box has a larger sector shaft. Actually, the only broken steering box I’ve ever seen was on a jeep outside of broken pitman arms. My theory is that loose pitman arm nuts are the cause of a broken sector shaft the same as with steering arm studs.
 
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This same thing has happed on both 80’s I’ve owned and to others I’ve wheeled with. Nothing conclusive has ever come from very thorough inspections of everything that makes up the steering and suspension up front in my case. Nor have I ever twisted splines. It is what it is. Usually a small adjustment of the drag link solves the issue as long as a misaligned steering wheel is the only problem. I see no need to over think it and sector shaft splines should not need to be inspected with a laser. Keep that pitman arm retention nut torqued. It’s on my pre-run check list.

The broken sector shaft hysteria is just that, over blown hysteria. I’ve ran Saginaw boxes on other 4x4 vehicles that I bounced off rocks and never broke a sector shaft on those and 80 steering box has a larger sector shaft. Actually, the only broken steering box I’ve ever seen was on a jeep outside of broken pitman arms. My theory is that loose pitman arm nuts are the cause of a broken sector shaft the same as with steering arm studs.
Good to have another perspective from someone that didn't see obvious damage after hit but still wheel off center.

Since you mentioned pitman arm nut torque, when I removed mine it was not on very tight. Not loose just only took light tug to move. On this 80 prob untouched since factory, so either the hit broke it loose or these can loosen over time. The pitman arm however was on the spline pretty tight. So good point about checking torque on pitman nut.
 
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This same thing has happed on both 80’s I’ve owned and to others I’ve wheeled with. Nothing conclusive has ever come from very thorough inspections of everything that makes up the steering and suspension up front in my case. Nor have I ever twisted splines. It is what it is. Usually a small adjustment of the drag link solves the issue as long as a misaligned steering wheel is the only problem. I see no need to over think it and sector shaft splines should not need to be inspected with a laser. Keep that pitman arm retention nut torqued. It’s on my pre-run check list.

The broken sector shaft hysteria is just that, over blown hysteria. I’ve ran Saginaw boxes on other 4x4 vehicles that I bounced off rocks and never broke a sector shaft on those and 80 steering box has a larger sector shaft. Actually, the only broken steering box I’ve ever seen was on a jeep outside of broken pitman arms. My theory is that loose pitman arm nuts are the cause of a broken sector shaft the same as with steering arm studs.
I tend to agree.

Hey, since you went through the headache of pulling the pitman arm, I’d rebuild that steering box.
 
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Last year I hit a curb fairly hard after having recently adjusted my relay rod to straighten the wheel. The impact knocked the steering wheel back out of straight. I couldn't see anything off, but I figured with the relay rod ends being relatively fresh (i.e. not frozen in place by decades of rust) the arm may have "self adjusted."
 
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This same thing has happed on both 80’s I’ve owned and to others I’ve wheeled with. Nothing conclusive has ever come from very thorough inspections of everything that makes up the steering and suspension up front in my case. Nor have I ever twisted splines. It is what it is. Usually a small adjustment of the drag link solves the issue as long as a misaligned steering wheel is the only problem. I see no need to over think it and sector shaft splines should not need to be inspected with a laser. Keep that pitman arm retention nut torqued. It’s on my pre-run check list.

The broken sector shaft hysteria is just that, over blown hysteria. I’ve ran Saginaw boxes on other 4x4 vehicles that I bounced off rocks and never broke a sector shaft on those and 80 steering box has a larger sector shaft. Actually, the only broken steering box I’ve ever seen was on a jeep outside of broken pitman arms. My theory is that loose pitman arm nuts are the cause of a broken sector shaft the same as with steering arm studs.
FWIW I twisted a sector shaft. The pitman arm was on so tight i had to cut the shaft to get it off and then a 50 ton press barely was able to get the stub out so I‘m not so sure about the loose pitman arm theory.
 
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Those splines look twisted to me in the picture. But I agree with the above statement that your issue is likely a sum of several small issues combining.
 
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The broken sector shaft hysteria is just that, over blown hysteria. I’ve ran Saginaw boxes on other 4x4 vehicles that I bounced off rocks and never broke a sector shaft on those and 80 steering box has a larger sector shaft. Actually, the only broken steering box I’ve ever seen was on a jeep outside of broken pitman arms.
I know of at least 5 twisted and/or also broken 80 series sector shafts. One of which showed signs of having been cracked for awhile before it broke, and that one didn't show obvious signs of a twist when it was installed a few weeks before the failure. None of those had loose pitman arms at the time of failure. There's a reason Toyota upgraded the shaft. The 105 sector shaft is not just a different part for a different truck, it is the replacement for the 80 as well. You can't buy the old style.
 
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Thanks everyone for your input. I think I may just suck it up and rebuild the steering box with 105 sector shaft. If this is a mall crawler I'd probably won't bother, but this is mainly use as family overland rig. I don't do hard crawling but I do go remote so don't want to be stuck in middle of no where with broken shaft. At least I get somewhat of an upgrade out of this ordeal. There is some 6 to 12 play when wiggling the tire, so bearing probably starting to go so I may just rebuild the knuckle and replace tie end too to freshen up the whole front-end.
 
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Looking at your pics again. The one looking from inside towards your knuckle. There looks like a freshly opened seam between the arm and the bottom of the knuckle. Which makes sense as right there is where the stud broke. Looks like the arm may have twisted clockwise if looking from the front. Wouldn't be surprised if you find the outboard front stud bent as well or stretched.
 
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I know of at least 5 twisted and/or also broken 80 series sector shafts. One of which showed signs of having been cracked for awhile before it broke, and that one didn't show obvious signs of a twist when it was installed a few weeks before the failure. None of those had loose pitman arms at the time of failure. There's a reason Toyota upgraded the shaft. The 105 sector shaft is not just a different part for a different truck, it is the replacement for the 80 as well. You can't buy the old style.
Bloody hell. I’ll be more careful next time I’m at the mall looking for some gear to buy.

I usually show those curbs and parking blocks what time it is. Who knew?

😜
 
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Looking at your pics again. The one looking from inside towards your knuckle. There looks like a freshly opened seam between the arm and the bottom of the knuckle. Which makes sense as right there is where the stud broke. Looks like the arm may have twisted clockwise if looking from the front. Wouldn't be surprised if you find the outboard front stud bent as well or stretched.
Yeah it's very hard to assess if arm is bent without good one to compared to. But you're right, given where stud broke it does make sense that arm bent clockwise which would explain steering wheel off in driver direction. Maybe I'll start with new arm since cheaper than messing with steering box.
 
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recalled jack stands? :nailbiting:
I've checked, my sku is not on the recall list, but I'm still mindful of it. Notice the tires are still on.... hahah. If I'm getting under and tires are off, I will have a secondary backup support either a tire or another set of stands ( I have another set of HF 12 ton ones... assuming those are better.. haha). Thanks for watching out for my well being ;)
 

baldilocks

Battle Ground, WA
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I know of at least 5 twisted and/or also broken 80 series sector shafts. One of which showed signs of having been cracked for awhile before it broke, and that one didn't show obvious signs of a twist when it was installed a few weeks before the failure. None of those had loose pitman arms at the time of failure. There's a reason Toyota upgraded the shaft. The 105 sector shaft is not just a different part for a different truck, it is the replacement for the 80 as well. You can't buy the old style.
Driving style has mostly to do with what gets broken with maintenance a close second place factor. Some people could break anything.
 
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Driving style has mostly to do with what gets broken with maintenance a close second place factor. Some people could break anything.
This is true. None were mine, 3 of those were the same guy, although one of those had previously been on my truck (and is the one suspected of being pre-cracked). All of them were hits to the passenger side wheel, on trails. What's concerning is that the comment 'I didn't think I hit it that hard' is common. Of course, hitting an immovable object at 10 mph might not seem like 'that hard' but stopping 3 tons of anything moving at any speed instantly takes a lot of force.

Also, with an improved sector shaft in place, I don't know what becomes the 'fuse' in the system. Probably the steering arm.
 

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