Saginaw Questions - 40 series turn radius (1 Viewer)

RWBeringer4x4

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Hey all,

My FJ40 has a Saginaw power steering setup. On road, it does great - it’s almost too much, and offroad the boost is awesome. However, I’ve noticed when I’m wheeling with the 80 and 100 series trucks I’m frequently out with, that I feel like the 40 can’t make the turns the bigger trucks don’t seem to struggle with. I feel like my tires are almost constantly at “lock” and I’m always wishing I could turn just a little bit tighter.

I’m 100% willing to accept that I may just be picking a bad line that is forcing me into a K-turn situation, but I wanted to get some thoughts from other folks with this setup and opinions on mine.

Currently I have a 1.5” drop arm measuring about 5.5 - 5.25” long center to center.

C088AC71-FF76-4194-A888-81F51D487A54.jpeg


This has the relay rod almost perfectly parallel to the tie rod - right where I want it to be.
EC855ACE-BDC8-4D16-A542-3FE0E61FBA1D.jpeg


The limiting factor in my turn radius is the steering box. It’s a 4.25 turn Saginaw box, and I’m using all 2.125 turns in both directions. The steering stops are adjusted to prevent over-extending the box, NOT to prevent conflicts with the body or frame.

I currently have 31” tires and they clear the frame and fenders by a solid 5” in either direction with the truck on flat ground so clearance isn’t an issue.

That said, my steering stops are adjusted almost all the way in - I can only back them off about another 1/4” or so before I run out of adjustment on the stop, so I’m not sure if I’m chasing a phantom issue here.

A2A5A6CB-BC3D-4726-AB32-45469F472255.jpeg


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Does 1/4” extra turn at the wheel stops make a huge difference to the radius? If so, how do I get it? My thoughts are a longer pitman arm, but it seems like all the major vendors drop arms are roughly the same length as the one I currently have, which leads me to suspect it’s probably the “right” length (or the only one available).
 
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You absolutely have to adjust your steering stops on the axle housing to protect the Saginaw gear box!!!!!!! A longer pitman arm will only speed up your steering, but with a 4.25 turn box that's not a bad idea anyway, just don't know where you are going to get a longer arm with the "drop" you want.
 

RWBeringer4x4

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You absolutely have to adjust your steering stops on the axle housing to protect the Saginaw gear box!!!!!!! A longer pitman arm will only speed up your steering, but with a 4.25 turn box that's not a bad idea anyway, just don't know where you are going to get a longer arm with the "drop" you want.
Yeah the stops are currently adjusted to protect the box. What I’m looking for is more “swing” so I can back the stops off a bit and get a tighter turning circle.

I guess my question is, am I splitting hairs? I can only back the stops off 1/4 inch more - is that a huge difference in terms of steering?
 

reddingcruiser

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Rick,

Actually, if you move the lock nuts to the back side of the boss, you can get a whole lot of turning angle if the gear box or pitman arm will allow it.

BUT, 'Backing off" the stops comes with its own risk. The further you allow the knuckle to turn the more you risk blowing up a birf.
 

RWBeringer4x4

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Rick,

Actually, if you move the lock nuts to the back side of the boss, you can get a whole lot of turning angle if the gear box or pitman arm will allow it.

BUT, 'Backing off" the stops comes with its own risk. The further you allow the knuckle to turn the more you risk blowing up a birf.
Very valid point. I guess that’s why I was hoping for some reference shots of other folks steering stops. If I’m just asking for too much and the truck just has a wider turning circle than I expect, so be it. It’s not unbearable I just think it’s weird when a big moose of a 100 series makes a turn that for some reason my 40 can’t seem to navigate. I’m perfectly willing to accept that it might be me who can’t navigate it, and not the truck, if that’s the reality of the situation.
 

reddingcruiser

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Comparing the 40's turning radius to an 80 and hundie is apples and oranges. When you go from leaf springs to coil springs there is more room to turn the tires. if you add bigger tires and really turn in the stops your tires will be rubbing the springs or frame when your suspension articulates.

My '04 Ford F250 has leaf springs and takes a lot more room to turn than a newer, coil spring F250. Just the nature of the beast.
 

RWBeringer4x4

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Comparing the 40's turning radius to an 80 and hundie is apples and oranges. When you go from leaf springs to coil springs there is more room to turn the tires. if you add bigger tires and really turn in the stops your tires will be rubbing the springs or frame when your suspension articulates.

My '04 Ford F250 has leaf springs and takes a lot more room to turn than a newer, coil spring F250. Just the nature of the beast.
If you (or anyone else reading) can snag a picture of your steering stops I’d appreciate it. Just wondering how far off mine are by comparison to what’s “normal” (if they’re too long at all).
 
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I don't know if this will help but here is a picture of my stop setting.

20201027_114459.jpg


4.25 lock to lock box with Borgsen 7" center to center straight pitman arm.
 

RWBeringer4x4

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I don't know if this will help but here is a picture of my stop setting.

View attachment 2478667

4.25 lock to lock box with Borgsen 7" center to center straight pitman arm.
Thanks! That's what I was looking for. Looks like you might have it a turn or two farther in than mine, if that. I still have no idea if, when it comes to turn radius, that's a drastic difference or not.
 
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@B y r o n - is your truck lifted at all? Any issues with the steering linkages being out of parallel with a flat pitman arm?
Yes, it is lifted 2" OME. (UPDATED: Just went back and looked at the parts I used; CS001F springs on front and CS001R for rear. Data on front springs states 1 1/2" lift while rear is 2".) My pitman arm is approximately where the factory bellcrank arm was. I have additional photos here.

I found a cleaner picture that shows the angle of the rods better.

DSC00317.JPG
 
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RWBeringer4x4

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Yes, it is lifted 2" OME. (UPDATED: Just went back and looked at the parts I used; CS001F springs on front and CS001R for rear. Data on front springs states 1 1/2" lift while rear is 2".) My pitman arm is approximately where the factory bellcrank arm was. I have additional photos here.

I found a cleaner picture that shows the angle of the rods better.

View attachment 2478850
In inherently mistrust a truck that clean ;)

Picture very my appreciated! Obviously in a perfect world they’d be parallel but that doesn’t look too bad to me.
 

brian

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I dont recall exact details but when I moved from a shackle reversal and sag steering back to strong arm and non reversed geometry....my turning rad increased.....with the 3.25 or 3.75 or whatever the fast ratio box is...it seemed like the front wheels had a sick range of travel from center to lock....like U turn between the curbs of most streets effortlessly. I cant recall if the steering stops were removed entirely or just opened up all the way.....the down side was that it had lunched a few birfs over the years.
 

RWBeringer4x4

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I dont recall exact details but when I moved from a shackle reversal and sag steering back to strong arm and non reversed geometry....my turning rad increased.....with the 3.25 or 3.75 or whatever the fast ratio box is...it seemed like the front wheels had a sick range of travel from center to lock....like U turn between the curbs of most streets effortlessly. I cant recall if the steering stops were removed entirely or just opened up all the way.....the down side was that it had lunched a few birfs over the years.
Lunching birfs is something I’d like to avoid. I think I might actually have the old straight pitman arm my truck came with laying around from before I added the drop arm. Can’t remember how long it was but might be worth looking at again...
 
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Hi Dow
You absolutely have to adjust your steering stops on the axle housing to protect the Saginaw gear box!!!!!!!
Hi Downey, can you elaborate?
Currently my saginaw stops rotating before the steering stops touch. It sounds like this is a bad thing..

How much do the steering stops need to limit box rotation, in order to protect the box? .. if that makes sense.
 

RWBeringer4x4

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Cruiser outfitters sells some saginaw pitman arms of various lengths and drops.
My 1.5” drop pitman arm is from cruiser outfitters. As far as I can tell there are various drops but the lengths are all the same 5.5 or 5.25, can’t remember which.

Like I said most of the time the steering is fine, but it would be great if it was a BIT more responsive on-road and had a little tighter radius off-road. I’m not sure a longer arm would solve the first issue but I am fairly certain it would solve the second.
 
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My 1.5” drop pitman arm is from cruiser outfitters. As far as I can tell there are various drops but the lengths are all the same 5.5 or 5.25, can’t remember which.

Like I said most of the time the steering is fine, but it would be great if it was a BIT more responsive on-road and had a little tighter radius off-road. I’m not sure a longer arm would solve the first issue but I am fairly certain it would solve the second.
A longer arm would definitely quicken the steering on-road. I am currently working the opposite direction... I have a 2.75 turn box and had a 7" arm. The turn radius was tight, but it was scary responsive on road. I went to a 5.25" (I think) arm, and it tamed the quick on-road steering, but I lost quite a bit of turn radius.
Long story short...
Longer arm = tighter turn radius and quicker steering.
 
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RWBeringer4x4

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A longer arm would definitely quicken the steering on-road. I am currently working the opposite direction... I have a 2.75 turn box and had a 7" arm. The turn radius was tight, but it was scary responsive on road. I went to a 5.25" (I think) arm, and it tamed the quick on-road steering, but I lost quite a bit of turn radius.
Long story short...
Longer arm = tighter turn radius and quicker steering.
This is exactly what I'm looking for. with a 4.25 turn box, and a 5.25ish inch pitman arm, steering on-road is pretty sluggish (tough to stay in my lane on twisty back roads) and offroad my turn radius is just a little too wide off-road. A longer pitman arm would help address both issues.

1.5 - 2" drop and 6.5-7" long would be absolutely perfect, if my thinking is correct, but almost nowhere advertises pitman arms by their exact dimensions. It's always "For X Vehicle with Y Lift" which tells me nothing about the actual dimensions of the arm.
 

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