Steering- Help me manage my expectations! (1 Viewer)

[Pierps]

Hi all, my restoration is just about done- I'm just working through some punch list items at this point.

I'm wondering if my steering behavior is normal. Before the resto, my rig had 35" tires, a rancho lift, worn out TREs, etc. So never really had a good baseline for comparison.

My rig has a brand new medium duty old man emu lift and shackles, brand new TRE's, brand new 235/85R-16 BFG KO2's, a mini truck power steering conversion (prior owner addition), and 4 degree steel caster shims. Brand new rag joint. I have the toe angle set to about 1/4" inwards. I've done my best to adjust as much free play out of the steering box as possible.

It doesn't dart around or hug ruts in the road like it did before the caster shims. But the wheel doesn't return to center very well (if at all), and I feel like I'm constantly correcting the steering back and forth to stay in the middle of my lane at speed.

Is this just the reality of an old leaf sprung, solid axle, short wheel base vehicle? Or should I expect better?

Thanks!
Peter

 

[fjc-man]

How’s your steering center arm? Have you tried adjusting out excessive play? Maybe it’s too worn and needs to be rebuilt.

 

[Pierps]

Thanks- I'll start doing some research. I didn't touch the center arm as part of the restoration.

 

[sogncab]

Is this just the reality of an old leaf sprung, solid axle, short wheel base vehicle? Or should I expect better?

Don't forget "cheap" and "designed seventy years ago"

But yes.

The wheelbarrow has more in common with an FJ40 than a modern vehicle.

 

[bikersmurf]

Without driving it, it’s hard to say. I’m currently running 33x10.50s. I’ve never driven it with new TREs… and also haven’t driven it since adding castor shims.
When I got it it was toed out… brutal. Almost impossible to keep on the road. After aligning to 1/8” toe in, 100x better.
With old 33x12.50s with worn bushings it took effort to keep it in the lane.
With new 33x10.50s it didn’t return to centre on its own but was easy to get to straight. It also stayed driving straight down the lane with little effort despite needing the front axle rebuilt.
Drove it a bit after Scout II steering swap. It feels like stock P/S should… not floaty or light… but takes nothing to turn the steering wheel (even at a dead standstill).

I’ve now replaced all the TREs, have a rebuilt front axle, and added castor shims… can’t wait to see how it drives.

1/4” seems too far toed in. 3mm at road surface of tires is my go to.

Tightening to reduce play can cause steering issues. To tight can be dangerous. Centre arm and reducing toe in would be where I’d start.

I never rebuild my centre arm, but did swap in a 1/2 decent one… when I started out, it was badly worn. Now it’s eliminated so it’ll no longer be a concern.

 

[igotta40]

Other than replacing the consumables (bushings, tie rod ends, etc.), all adjustments to the steering box, drag link, center arm and alignment in spec, all original factory parts, mine tracks boringly straight & true, no wandering at all.

 

[Subterranean Nik]

Would check the steering box.

“I've done my best to adjust as much free play out of the steering box as possible”

I did same to my brother’s 40 years back and it would not return to center after I tightened it up. Consider loosening up a little. Found below thread as well.

Good luck! Let us know how it goes.

Steering Wheel Play Adjustment

Service manual indicates 1 inch play is factory spec, I have close to 3 inches of play, with equal amount in each direction( 1 and 1/2 inches each direction) and smooth. The 3 inch play measurement was done while watching the sector roller shaft for movement. From the manual: "The steering...

forum.ih8mud.com

Nik

 

[77mustard40]

^^^ I have roughly the same setup, but I’m on 4” skyjackers. I rebuilt my leaking box a year ago and without the SST’s getting the box dialed in was a feel thing. I found that when torquing the outer lock nut it was actually turning the adjustment screw no matter how hard I tried to hold it. Try backing it off a quarter turn and see if you can solve the return to center issue. If that turns out to be the culprit then you can experiment with snugging up the adjustment in small increments.

Mine tracks straight with about 1/8” toe in, returns to center but I wouldn’t describe the feel as tight. I have a small amount of steering wheel play but don’t really notice it while driving, feels like an FJ40 with power assist. I don’t think there is a way to get a tight feel without ditching the drag link and center arm so that you have direct steering input from the pitman arm. Think FJ60, FJ80, Saginaw etc. conversions… not getting into that debate.

 

[70 FJ40]

I had a similar issue after doing a steering system and front axle rebuild. My steering is all stock but it turns out I had tightened down my centerarm too much. In the process of it all I tightened and loosened my steering box several times thinking that's where the problem was. I could tell when I had gone too far on the steering box. Anyway, I think it's possible you may have over tightened the adjustment on the steering box. I was advised to go a 1/4 turn at a time then drive it, adjust again. That seems to be the best advice I got for adjusting the steering box.

 

[Pierps]

Got it- super useful advice everyone!!! Lots of actionable things here.

-Center Arm rebuild. It is crusty- looks terrible bolted on to a freshly powder coated frame, so I was planning on taking it off and painting anyway
-Tinker with the steering box adjustment. If I recall correctly, when I adjusted it, I tried to take all free play out. Sounds like that is too much.
-Tinker with the center arm adjustment (no idea how to do this, but I'll figure it out)
-1/4" toe might be too much. I'm now second guessing my memory. I might've set it to 1/8", but easy to recheck. I researched this on the forum before doing the alignment.
-Consider rebuilding the minitruck box (how would I know whether this is needed? It's not leaking or making any noises)

Lastly- after dialing all of that in, don't expect it to handle great.

 

[sogncab]

Part of the issue with the factory steering is just the excessive number of parts for slop to develop.

Wheel bearings.
Pinion bearings in the spindles
Tie rod ends
Drag link ends
Center arm
More freaking tierods
Steering box
Then whatever is going on between the steering wheel.

Tire condition too. New tires show flaws much more so than worn in tires where the lug edges are no longer sharp and grabby.

I had mybsteeeing box rebuilt after my reman box started leaking. It sucked until it wore in a little. Everything was a twinge too tight for the first few hundred miles and the center of the steering was way too sensitive.

I've got relatively new everything. It drives like I expect, but it still sucks compared to a new sedan. My F350 sucks compared to a modern sedan.

 

[iliketrucks]

It sounds like you moved in the right direction with the caster shims. You may want to call around and see if any local shops would be willing to throw it on the alignment rack and get you some measurments on the caster for cheap, then you'll for sure know if that's where it needs to be.

 

[B y r o n]

Got it- super useful advice everyone!!! Lots of actionable things here.

-Center Arm rebuild. It is crusty- looks terrible bolted on to a freshly powder coated frame, so I was planning on taking it off and painting anyway
-Tinker with the steering box adjustment. If I recall correctly, when I adjusted it, I tried to take all free play out. Sounds like that is too much.
-Tinker with the center arm adjustment (no idea how to do this, but I'll figure it out)
-1/4" toe might be too much. I'm now second guessing my memory. I might've set it to 1/8", but easy to recheck. I researched this on the forum before doing the alignment.
-Consider rebuilding the minitruck box (how would I know whether this is needed? It's not leaking or making any noises)

Lastly- after dialing all of that in, don't expect it to handle great.

There are numerous factors that affect handling. Each vehicle has it's own characteristics not to mention your own interpretations of how it is driving. My Corvette does not handle like my Ram truck and my FJ-40 doesn't handle like either of them. It doesn't mean my FJ-40 doesn't handle good but it will never handle like my Corvette.

 

[bikersmurf]

Got it- super useful advice everyone!!! Lots of actionable things here.

-Center Arm rebuild. It is crusty- looks terrible bolted on to a freshly powder coated frame, so I was planning on taking it off and painting anyway
-Tinker with the steering box adjustment. If I recall correctly, when I adjusted it, I tried to take all free play out. Sounds like that is too much.
-Tinker with the center arm adjustment (no idea how to do this, but I'll figure it out)
-1/4" toe might be too much. I'm now second guessing my memory. I might've set it to 1/8", but easy to recheck. I researched this on the forum before doing the alignment.
-Consider rebuilding the minitruck box (how would I know whether this is needed? It's not leaking or making any noises)

Lastly- after dialing all of that in, don't expect it to handle great.

Fron experience, I'd suggest pulling apart the center arm assembly before removing it from the frame. The bushings inside it will wear oval if it's not adjusted for too long. Once it's no longer round it's difficult (if not impossible) to remove play without it preventing centering.

I'd open it up and clean it out and see what shape it is in. If it's not too worn, you can pack it with fresh grease and adjust it. To adjust the center arm, loosen the locking bolt in the center, and then tighten the "nut" beneath it to tighten the preload on the tapered bushing. I've found that tightening it down till it doesn't easily turn, and then loosen it off till it turns with little resistance. I'm sure there's a preload spec... but when I was messing with mine most, I'd never even heard of a FSM and only had access to a Haynes manual... There wasn't even the internet back then.

 

[Pierps]

very helpful, thanks!

Are you saying I should leave it on the frame just to save time if it doesn't need a rebuild? I'm planning to take it off to clean and paint it anyway.

What are the signs that it needs a rebuild? Visible play (i.e., move the steering wheel back and forth, and see if the drag link is moving but the tie rod isn't?), or do I need to open it up like you suggested and look for wallowed out bearings?

 

[island45]

From memory there was something like this in the SOR catalogue back in the day. "Stand in front of the vehicle where you can see the center arrm and pivot. Have someone turn the steering wheel back and forth. If you see up and down movement on the arm, you need a rebuild kit".

 

[pb4ugo]

From memory there was something like this in the SOR catalogue back in the day. "Stand in front of the vehicle where you can see the center arrm and pivot. Have someone turn the steering wheel back and forth. If you see up and down movement on the arm, you need a rebuild kit".

Or the piviot point wobbles. It's easier to disassemble the top nut when it's still attached to the vehicle.