FJ40 wheel alignment

[Jacket]

Given that I've rebuilt my knuckles, and I've pulled the Tie Rod and Relay Rod to put new ends on them, I'll have to align the front wheels when I put it all back together. I marked the basic location of the old TRE's and RRE's on the bars so that I can install the new ends at nearly the same location. Does anyone have any tips or tricks for the alignment process, or am I safe to do something like:

1. Center the steering box
2. Mount the tires
3. Install (loosely) the new TR and RR
4. Measure the distance between the two back tires
5. Measure the distance between the two front tires
6. Adjust the TRE's to make 5=4

Should there be any toe-in? Anything else to adjust?

 

[nakman]

Yeah I think 1/16" toe in is the target... I would suggest the patented Rudy stick method http://www.risingsun4x4club.org/forum2/showthread.php?t=12375

 

[Air Randy]

The best way to do it is to place the front end on jack stands and pull the wheels off. Get 2 straight edges (like metal yardsticks) that you can clamp onto the flat surface of either the brake drum or brake rotor. You want the straight edges to protrude past the front and rear of the drum/rotors. Make sure they are clamped onto a flat surface that is the same on both sides.

Make sure the wheel is straight ahead. Measure the distance between the front straight edges and the rear. On my 40, since I have 39" tires, I run about 1/4" of toe-in. That makes it track very straight, it doesn't follow the ruts in the road and tire wear is good. If you have smaller tires you can try setting it up with less toe-in. Just repeat the procedure then test drive it. If you start getting to a point where the steering feels neutral, or if it wanders or follows ruts (or even wobbles) then you need to dial a little bit more toe-in into it.

 

[Jacket]

Thanks for the link and info. Drew's thread doesn't turn up when searching for "alignment", but it's got some good info.

or if it wanders or follows ruts (or even wobbles) then you need to dial a little bit more toe-in into it.

I thought wobbles and wandering were a given with FJ40 steering......

 

[Air Randy]

You can take your hand off of the steering wheel with mine at 70 mph and it's solid as a rock even with 39's. Of course you have to be going down hill in order to go that fast

 

[chrisbj]

Hi I'm brand new to 4x4, i just bought a fj40 after seeing it and having a "i have to have it" moment. problem i have with it now is it seems to wander all over the road, even at 35 mph it can go off course on a bumpy road, and once i get to 50 mph i'm scared to go any faster. it feels skittish. reading up on posts it seems like it could be a caster angle problem?
i think this because the steering is real light (manual steering) and how it is really jumpy. it's had a 2" body lift, and longer shackles to lift the springs another 1/2", running on 35" tyres.
would appreciate any advice to solve this?

 

[Uncle Ben]

1/16" toe is to little. 1/8" toe is pretty standard on most vehicles. Randy's method is the same I use. One thing he didn't mention is you want to measure the same distance from axle centerline both front and rear. Since you are using the intersecting line method measuring at different points on the line will give you different measurements. Rule of thumb is to measure where the tread of your tire would be. In example, if you are running 33" tires you need to measure out 16.5" from axle centerline for your alignment point front and rear. This method increases your toe slightly with larger tires which, as Randy points out, keeps them from hunting ruts.

 

[subzali]

Hi I'm brand new to 4x4, i just bought a fj40 after seeing it and having a "i have to have it" moment. problem i have with it now is it seems to wander all over the road, even at 35 mph it can go off course on a bumpy road, and once i get to 50 mph i'm scared to go any faster. it feels skittish. reading up on posts it seems like it could be a caster angle problem?
i think this because the steering is real light (manual steering) and how it is really jumpy. it's had a 2" body lift, and longer shackles to lift the springs another 1/2", running on 35" tyres.
would appreciate any advice to solve this?

First off, welcome to our club forum. For an issue like this it might be better for you to start your own thread, since your topic is different than the one being discussed here. But since you posted in this thread, I will give a couple of my thoughts. The first thing for your steering problem would be to check and make sure everything is tight. Is there play in your steering box? Center arm? Any of your tie rod ends? Is your rag joint in ok shape (I'm assuming you have a later model FJ40 with the rag joint setup, if you tell us what year you have that will help)? You can also pull the steering column out and check to see if the bushing at the base of the steering column is torn/disintegrated. Make sure your u-bolts are tight on your springs. What kind of condition are your shock absorbers in? They would affect how well the truck handles. The last thing I would check is your knuckle swivel bearings (kingpin bearings) and your front wheel bearings. If these are loose or worn they can add to excessive play; if your steering knuckles are leaking that's a good indicator that they need to be rebuilt, so get a rebuild kit and tear into them and put fresh knuckle swivel bearings in! Oh, and any time while you are checking into those things, it wouldn't hurt to take it down to an alignment shop and have them check the caster angle for you. It may be off considering your description of the suspension modifications that have been made...

 

[MDH33]

...it's had a 2" body lift, and longer shackles to lift the springs another 1/2", running on 35" tyres...

Here's the problem. Longer shackles in the front will change the caster and pinion angles causing the light steering you describe (I bet you have driveline vibration too). You should replace the longer shackles with stock length and go to a slightly smaller, narrower tire (especially with manual steering).

 

[Uncle Ben]

Here's the problem. Longer shackles in the front will change the caster and pinion angles causing the light steering you describe (I bet you have driveline vibration too). You should replace the longer shackles with stock length and go to a slightly smaller, narrower tire (especially with manual steering).

A set of 2.5* steel castor shims would help a lot too!

 

[Jacket]

Marco and I messed around with it a bit on Sunday, and we got it to about an 1/8" toe-in. I've had it out on the road for two days now, and it tracks really straight, steering seems tight and responsive, and as far as I can tell the whole rig feels tighter than it ever has. 70* days and cruisin' in the 40 is just what the doctor ordered!

 

[nakman]

That's awesome, Matt, nice work. And today's a 40 day if there ever was one..