Steering Issues (2 Viewers)

[OlliesGarden]

Just recently purchased my 1975 FJ40 and I've been troubleshooting some steering issues. She wanders and shimmies severely on rough roads. I've been reading about it and I'm thinking caster shims and new leaf spring bushings. Thoughts?

The FJ has a SOA conversion on stock springs and inversion kit. Running decently wide 37's as well. Recently replaced steering dampener, idler arm, and got an alignment. I attached an image of my current alignment.

 

[B y r o n]

You might want to read this regarding your caster needs.

 

[charliemeyer007]

Look at the center pivot and tie rod ends. Make sure your wheels are true and balanced amap. Shocks condition?. My 72 needs both springs and shocks. Even back when I bought it with only 62,000 miles its more of herding down the road.

 

[OlliesGarden]

Look at the center pivot and tie rod ends. Make sure your wheels are true and balanced amap. Shocks condition?. My 72 needs both springs and shocks. Even back when I bought it with only 62,000 miles its more of herding down the road.

I'll take a look at my pivot angle. Tie rods are in decent condition, nothing I feel concerned about. Brand new Bilsteins front and rear and the springs are a little saggy but I heard that's normal for an SOA.

 

[OlliesGarden]

You might want to read this regarding your caster needs.

This was very helpful, thank you!

 

[pb4ugo]

That things got to be handful with almost 2* of negative caster.

 

[pbgbottle]

Any pics what are you using for high steer setup?
double steering arm ,4x4 labs ,Marlin ?
also might be a factor I run 4-6 degrees with my 37,38 inch tires

 

[peesalot]

Caster should be 3 or 4 on a soa 40 IMO.

 

[peesalot]

Check spring/shackle bushings, do a cut n turn so you have 3 or 4 deg caster, check trunions for loose/worn bearings, check u bolts, you are still using a center pivot steering on a soa rig, whats the steering set up ?

 

[OlliesGarden]

Any pics what are you using for high steer setup?
double steering arm ,4x4 labs ,Marlin ?
also might be a factor I run 4-6 degrees with my 37,38 inch tires

I'll take some pics in the morning but as far as I can see there's no steering accommodations for the lift. I just bought the cruiser and all I can see is the front axle is swapped with an 80 series.

 

[OlliesGarden]

Check spring/shackle bushings, do a cut n turn so you have 3 or 4 deg caster, check trunions for loose/worn bearings, check u bolts, you are still using a center pivot steering on a soa rig, whats the steering set up ?

Here's a pic of my set up currently. Only thing I can see is it's swapped with an 80 series axle I believe. Bushings seemed in decent condition as well as the u bolts. I'll try a cut n turn as well as check my trunions.

 

[pbgbottle]

doesn’t look like a hack job just needs some tweaking I see shims in there already your using what we call a double steering arm on the passenger side knuckle there.
My buddy is running a almost identical setup to yours with stock steering and stock castor but he is on skinny 33 inch tires.
Looks like a stock 40 series front axle.

 

[OlliesGarden]

doesn’t look like a hack job just needs some tweaking I see shims in there already your using what we call a double steering arm on the passenger side knuckle there.
My buddy is running a almost identical setup to yours with stock steering and stock castor but he is on skinny 33 inch tires.
Looks like a stock 40 series front axle.

Awesome, glad to get a better understanding of what's going on. Just lifted those leafs up and found 4* shims. Going to grab 6* to set me closer to where I need to be. Any other ideas on how I can make my adjustment without a cut and turn?

 

[pb4ugo]

It looks like a decent install, you just need to dial in the steering geometry. Which way are the shims installed? Fat end towards the frt? Can you shoot a side pic showing the driveshaft angle in relation to the pinion?

 

[OlliesGarden]

It looks like a decent install, you just need to dial in the steering geometry. Which way are the shims installed? Fat end towards the frt? Can you shoot a side pic showing the driveshaft angle in relation to the pinion?

I'll post a picture of pinion angle once I'm off work. The shims are fat end forward. I believe that's the proper orientation due to the SOA, but may be wrong.

 

[pb4ugo]

You are correct. Fat end towards the frt. The reason folks do a cut and turn is because it's very difficult to get the proper caster you need to drive the vehicle comfortably and have the driveshaft in a good working angle and not have U joints in a bind. Once you install the 6 degree shims put the frt suspension in full droop and see if the d/s still rotates smoothly and the yokes dont bind with each other.
According to your alignment specs a 6 degree shims gets you close to "0" caster. The shims will help, but it's still probably not enough. I'd want somewhere between 3 and 5 degrees positive caster. Rotating the axle for more positive caster points the pinion down.

 

[Toyoland66]

Here's a pic of my set up currently. Only thing I can see is it's swapped with an 80 series axle I believe. Bushings seemed in decent condition as well as the u bolts. I'll try a cut n turn as well as check my trunions.

View attachment 3416639

FYI that’s not an 80 axle, probably a 60 axle if it’s wider than stock. That has LC/ mini truck knuckles, you can tell by the 4 bolt pattern for the steering arm and trunnion cap top and bottom. 80 axle has a 2 bolt trunnion cap on top and the steering arm attaches to the bottom. You have a crossover steering arm, appears to be a manufactured one and not a home brew.

You’re on the right track with a cut and turn.

 

[OlliesGarden]

You are correct. Fat end towards the frt. The reason folks do a cut and turn is because it's very difficult to get the proper caster you need to drive the vehicle comfortably and have the driveshaft in a good working angle and not have U joints in a bind. Once you install the 6 degree shims put the frt suspension in full droop and see if the d/s still rotates smoothly and the yokes dont bind with each other.
According to your alignment specs a 6 degree shims gets you close to "0" caster. The shims will help, but it's still probably not enough. I'd want somewhere between 3 and 5 degrees positive caster. Rotating the axle for more positive caster points the pinion down.

Amazing info, thank you so much. Shims come in tomorrow so I'll update the post keep everyone posted.

 

[pbgbottle]

If you have to you can grind /clearance the driveshaft yokes or joints a bit so they don’t bind up U will see where they bind up if they do. I myself have done the front cut-n-turn to my housing it Can be done with basic tools and a welder if your handy. My buddy is running exact same setup as you and NO cut-n-turn
he just clearance the heck out of his front driveshaft if ya don’t do a cut and turn right away try the shims first and see how it goes ,
you might consider Saginaw power steering conversion one day also it removes a few tie rods from the system and aids in tightening up the steering , my first ever SOA I did NOT. do the cut and Turn and my driveshaft binded up and twisted off my front pinion. What engine are you using. If still a Toyota 6 your front driveshaft is still fairly long. U might be able to avoid the cut n Turn if ya have to ,but start with the shims and see how she drives. I still think u may need your housing cut and turned in the long run as you will want to set your pinion angles also along with custom castor angle. Need lots of pics to see everything. We like pics. Even a pic of rear setup for fun just to see how your SOA was done , front drive shaft pic is helpful also. The whole shaft both ends. Cheers

 

[peesalot]

Shims ? - Fat end forward would put more neg caster ?
Please review and rethink which direction the shims go, IMO fat end toward rear so steering arms go up, pinion goes down.