Yet Another Saginaw Question - Very sensitive steering

[avgas]

OK so I've installed saginaw on my FJ40, it has a 2.5 inch OME lift and I used the Advance adapters kit. I have a 4.25 turn box. The steering is extremely sensitive, kinda scary on the road.

Although I have the 4.25 box, once the tie road is connected I only have 3 turns lock to lock. so this must be my problem. The question is how to correct it. I may be answering my own question but it seems like a shorter pitman arm would do the trick. Or do I need a drop pitman (which is inherently shorter)

Suggestions?

thanks,
jake

 

[rusty_tlc]

OK so I've installed saginaw on my FJ40, it has a 2.5 inch OME lift and I used the Advance adapters kit. I have a 4.25 turn box. The steering is extremely sensitive, kinda scary on the road.

Although I have the 4.25 box, once the tie road is connected I only have 3 turns lock to lock. so this must be my problem. The question is how to correct it. I may be answering my own question but it seems like a shorter pitman arm would do the trick. Or do I need a drop pitman (which is inherently shorter)

Suggestions?

thanks,
jake

A shorter pitman arm would have a smaller radius, wouldn't that result in quicker turning for the same amount of rotation on the gear box O/P shaft?

Why would a drop pitman arm be inherently shorter?

 

[avgas]

Most drop pitmans Ive seen are the same length only bent, giving it a smaller radius. Right now the radius is too big the pitman is swinging wide so it doesnt allow the box to move from lock to lock if the "circle" was smaller it would allow more movement inside at the pitman in relation to the steering arms.

 

[Mark W]

Your pitman arm is probably too long (how long is it?).

There are longer and shorter pitman arms. Flat and dropped.

A shorter arm will help with your problem.


Mark...

 

[avgas]

Thanks Mark,

I don't have it in front of me, but I think it's around 7 inches long. Do you know of a vendor that carries the shorter arms?

jake

 

[Mark W]

7 inches should be about right. It is not long enough to cause that sort of steering impact. For comparison, the 9.25 inch arm off a ScoutII will turn that 4.25 rurn box into a 2.5 turn system if it is used on a Cruiser. 7 inches or so is the usual length for pitman arms used on Cruiser conversions.

BTW, drop arms are intended to be the same length as no drop arms (in terms of the arc that they cover) they would be longer if hammered flat.


Do you have the sme number of turns to each side from center? What does the rest of your steering system look like.

If you are connecting to a double knuckle arm and have not done anything about the mis-matched angle of the pitman arm and the knuckle arm, then you will have steering the moves faster (less turns) in one direction than the other. It has been a while since I looked closely at this, but you might loose that much, or close to it just from that.

Are your steering stops adjusted in a good bit too?


Mark...

 

[dgangle]

...just for reference, here are two pitman arms showing lengths and drop. The top is the straight arm that came as part of a Downey kit ~9 yrs ago. The bent arm is from a Cherokee, IIRC. I settled on an arm that was about 1/2 of the amount of drop as the one pictured. You may also want to measure your caster.

 

[avgas]

Mark, What do you mean by "double knuckle arm" I'm connecting to stock knuckle arms. Steering seems about the same amount of turns on each side (1.5). The steering stops do seem in a bit, but not what I would think would be enough to radically limit the steering by a half turn each way.

dgangle, the one I have now is exactly like one in the top picture . I found one like you described(midway drop between straight and the cherokee arm) in the pitman arm box at a local 4x4 junk yard today at lunch. provided the taper is correct I'm gonna give it a try as it's at least an inch shorter in overall length.

 

[avgas]

Just an FYI the shorter arm worked, or helped. I know have about 3.75 turns lock to lock. I could probably get to 4.25 if I adjusted the knuckle stops