Lets talk suspension and steering problems...... (1 Viewer)

Joined
Dec 2, 2018
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217
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Idaho
I need some help understanding my steering behavior and what adjustments I can make to improve it. Thanks in advance for your help. Here's my story:

My 76 fj40 was restored/refurbished at some point in previous ownership and is in very good mechanical and cosmetic condition. I drive it most days and it does great. 2F, headers, DUI, Weber 36/32, Mini truck PS, H42 4 speed trans, don't know what the diff gearing is, 31X10.5r15 BFG AT KO2 on stock spoked wheels. Suspension appears stock except for shackles, which are maybe 2" longer than stock. Tie rod ends are newer and tight.
It can go 75 if it needs to, and runs straight without wandering or feeling loose.

My issue:
When turning. Small steering wheel inputs deliver small adjustments in course, which is feels correct, but then there is a delay of sorts before the rig turns more, then it wants to turn all at once. This is also the point where body roll is initiated and is more pronounced than I would like. On paved mountain roads it is not very fun to drive because of this parabolic feeling of the turn radius.

Related info:
In the near to medium future I would like to up-size to 33x21.5r15 on 15x10 wheels. 2" front lift and 4" rear lift accomplished with new springs or re-arching the OEM.

I've done a little reading on the topic and I feel like I have a combination of both understeer and over steer. It is certainly understeer in the first phase of turning the steering wheel, but then it seems to all catch up and might feel like over steer once the body has begun to roll and the front end in really coming around.

What are my likely problems and how do I assess them to rule them in or out as the issue?

I
 
Joined
Dec 2, 2018
Messages
217
Location
Idaho
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Joined
Jul 31, 2017
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Frazier Park Ca
I agree with the shims, lifts etc will alter the angle on the knuckles. They a need to be pretty straight vertically. I have 6 degree shims with my 4 inch lift. IMO don’t use aluminum shims!
 

jim land

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Aug 6, 2007
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scott quebec
And for 33 x 12.5 , I think 8" rimes look better , or 33 x10.5 on 5.5" steelies for a more true 40 look .

In the end its your 40 and you can do it like you want :cheers:
 
Joined
Dec 2, 2018
Messages
217
Location
Idaho
Why 4" springs in rear only. ?
Measuring from the gutter to the ground, the rear of the rig is considerably lower than the front, and I have some cruiser lean that I’ll need to correct. I am leaning towards having the original springs re-arched locally.
 
Joined
Dec 2, 2018
Messages
217
Location
Idaho
And for 33 x 12.5 , I think 8" rimes look better , or 33 x10.5 on 5.5" steelies for a more true 40 look .

In the end its your 40 and you can do it like you want :cheers:
I can’t get on board with the skinny tire factory look. I like a wide stance and deep wide rims.
 
Joined
Jan 12, 2008
Messages
3,088
Location
West MI near GVSU
Put the front axle on jack stands and cycle the steering all the way right and left, noting how it feels at any point. Then maybe try it with the engine running to see if the PS changes the behavior/feel.

Maybe do the same operation agaon off the jack stands with the tires on grease plates.

Is the PS pump/pressure valves operating correctly? Is the fluid low?
 

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