Correct caster angle for front axle FJ40? (1 Viewer)

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Sep 16, 2004
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Ive been reading posted threads regarding "Death Wobble" and "Wandering Steering" linked to removing roof top and doors/ and or installing taller shackels. I am experiencing the same problems with my cruiser as well. with a side to side shaking at about 35mph and stopping at around 50mph. This only occurs when the top is removed.My problems started when i installed a MAF Swing away Rear Tire carrier/Bumper. The added weight of the beefy bumper and 35" wheel&tire spare caused the rear of the cruiser to sag about 2 inches. It had 2 3/4 inch tall shackes front and rear, so i replaced the rear with a set of Con-Ferr 5 3/4 inch shackles and it leveled out the rake just right. Even with the roof on, i do experience some "Wandering". I am running a Chevy V8, Downey 4" SUA lift and AGR power steering.
My Question:
Could the extra weight and taller shackels on the rear , and lighter V8 engine affect the steering/wandering /shaking issue? Im going to have the wheel balance checked as well. and finally, what should the correct caster angle be for the front axle?
Any suggestions would be helpfull
 
Joined
Sep 16, 2004
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I think you are right Fuzzy, based on all the info ive been finding in the forums. Question is: should i shoot for the +1 degree caster from factory specs. even though my suspension is not "Factory" ?
 

Cruiserdrew

On the way there
SILVER Star
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1 degree is stock, 2-4 degrees is more comfortable with big tires.

Read up on DW. Any loose or out of spec component in the front can cause it. How old are your TREs? How about your spring bushings? Wheelbearings tight?
 
Joined
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Messages
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1 degree is stock, 2-4 degrees is more comfortable with big tires.

Read up on DW. Any loose or out of spec component in the front can cause it. How old are your TREs? How about your spring bushings? Wheelbearings tight?
Thanks Drew...all my components were new or rebuilt within weeks of the DW.
 
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As an ex wheel alignment guy, most cars and trucks are 1-2 degrees positive. Some big trucks are +3. More than that and you unnecessarily increase the steering effort and you will wear the edges of your tires in turns. You also lose contact patch area in turns, which may make the front end slide out in turns, which could be dangerous.
 

Josie'sLandCruiser

Stop calling it a "FJ."
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Hi All:

It seems to me that your issue is related to the weight over the rear axle and the length of the rear shackles.

Buy a "Silver Star" and post up some pics of the rear shackle angle with the hardtop removed.

Good luck!

Alan


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Ive been reading posted threads regarding "Death Wobble" and "Wandering Steering" linked to removing roof top and doors/ and or installing taller shackels. I am experiencing the same problems with my cruiser as well. with a side to side shaking at about 35mph and stopping at around 50mph. This only occurs when the top is removed.My problems started when i installed a MAF Swing away Rear Tire carrier/Bumper. The added weight of the beefy bumper and 35" wheel&tire spare caused the rear of the cruiser to sag about 2 inches. It had 2 3/4 inch tall shackes front and rear, so i replaced the rear with a set of Con-Ferr 5 3/4 inch shackles and it leveled out the rake just right. Even with the roof on, i do experience some "Wandering". I am running a Chevy V8, Downey 4" SUA lift and AGR power steering.
My Question:
Could the extra weight and taller shackels on the rear , and lighter V8 engine affect the steering/wandering /shaking issue? Im going to have the wheel balance checked as well. and finally, what should the correct caster angle be for the front axle?
Any suggestions would be helpfull
 
Joined
Sep 16, 2004
Messages
286
Location
Southern California
 
 
 
Good info Pinhead! Hey i see you are in the OC. I'm in Diamond bar. Could you recommend a reputable alignment shop to check out my caster and also do a wheel balance on my 35/15/12.0 mud terrains?
 
Joined
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I used to know a good alignment guy in Costa Mesa, but he went out of business. I haven't turned a wrench for a living in 30 years, but that just happens to be around the time that cruisers were new.
 
Joined
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IIRC factory spec for your rig is 1-2 positive... this works fine for modified rigs too...


The items you mentions should not have any effect on your steering... not to the point of causing these problems


Look at everything in your front suspension that might be loose but is supposed to be tight.
Bearings, bushings, nuts and bolts... Ubolts, TREs, steering box... Everything. Look to see if anything that is meant to be straight is bent. Badly out of balance tires, or old "should be trashed" deteriorating tires can be a problem. I have seen cracked frames show them selves by causing DW too.

do you not have any caster shims in there at all?


Long shackles on the front end call for shims... many lift springs need shims even with stock lenght shackles


Mark...
 

Waggoner5

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I found that the larger the tire and larger amount of lift you have, the more caster you will want to run. Your death wobble can come from lots of different things though and adding + caster most likely will not help, but may make things worse. Have it checked first, and while they are doing it have them check wheel bearings, trunion bearings and all tie rod ends.
 

Josie'sLandCruiser

Stop calling it a "FJ."
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Hi All:

If this is the rear shackle angle with the hardtop on, then it is sure to be vertical when the hardtop is removed.

Poor rear shackle angle and less weight over the rear axle probably are not the source of problem, but makes it more obvious.

I'd look for an "old school" type auto shop that can do alignments on leaf-sprung 4x4s and have them check-out things on the rig.

Good luck!

Alan

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View attachment 304215 Here is a pic of the shackle angle currently with the top on
 

Poser

Oh...Durka Durka Durka.
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