Builds fj60 going to EV FJ45 (1 Viewer)

[workingdog]

So, the links are tacked together and in

the lowers are parallel and the uppers triangulated. Is there any need to triangulate the lowers as well? I've never fully groked how much triangulation is needed to eliminate panhard bar. With a bunch of work, I could build a cross member for the lowers to land on. But I'm not sure it's worth it.

 

[workingdog]

@DangerNoodle @NightFury Need more practical sage advice

So, similar question on the front suspension.

Here is the stock lower link location and arrow to where I came put the lower link (and it's not too much work), this would take the lower links from about 5 degrees to over 20 degrees of angle to the frame. I assume that's worth it. But, is it enough to get rid of the front panhard?

This is the upper links. By putting a truss in, I think I can move the upper links in about 4 inches, which takes the angle from less than 5 degrees to maybe 15 degrees. Is that worth it? I can't take them any farther inboard without moving the motor up, which is quite a bit of work - but possible.

 

[DangerNoodle]

@DangerNoodle @NightFury Need more practical sage advice

So, similar question on the front suspension.

Here is the stock lower link location and arrow to where I came put the lower link (and it's not too much work), this would take the lower links from about 5 degrees to over 20 degrees of angle to the frame. I assume that's worth it. But, is it enough to get rid of the front panhard?

View attachment 2773773

This is the upper links. By putting a truss in, I think I can move the upper links in about 4 inches, which takes the angle from less than 5 degrees to maybe 15 degrees. Is that worth it? I can't take them any farther inboard without moving the motor up, which is quite a bit of work - but possible.

View attachment 2773780

I'm assuming you want to try and elimante the panhard up front, yes?

I would highly advise against that, as you need to front axle to move in an arc for mechanical steering. If you are going full hydro, send it, but your drag link will move in an arc, and if the axle does not want to, you will be getting some serious, past undrivable bump steer every time you hit a bump and the axle wants to move in a straight line upwards.

 

[workingdog]

@DangerNoodle - thanks. I hadn't realized that, but it's obvious now that you point it out.

So, is there any advantage to triangulating at all? Or just leave it parallel like it was stock?

Also, in the post above the one I flagged you in, do I have enough triangulation to eliminate the rear panhard?

 

[DangerNoodle]

@DangerNoodle - thanks. I hadn't realized that, but it's obvious now that you point it out.

So, is there any advantage to triangulating at all? Or just leave it parallel like it was stock?

Also, in the post above the one I flagged you in, do I have enough triangulation to eliminate the rear panhard?

Some triangulation is good, but completely unnecessary if you have a panhard. It's up to you.

 

[workingdog]

But, in the rear, I'd like to get rid of the panhard, in post #241, is that enough triangulation?

 

[DangerNoodle]

But, in the rear, I'd like to get rid of the panhard, in post #241, is that enough triangulation?

It looks like it would be enough. I'd tack it in and articulate it to see if there is much movement and adjust from there.

 

[Godfather90]

This might be a dumb question but wouldn't triangulation in the front create axle skew throughout the suspension travel when coupled with a panhard? Rather than a typical side to side movement?

And if it were a triangulated 4 link with a panhard I can't picture it working without being over constrained and binding?

 

[workingdog]

@DangerNoodle - Thanks so much. It's all tacked up, I'll get the floor jacks and run it through, I have to figure out where full bump is anyway.

@Godfather90 - I was thinking the same thing. I assume if I'm going panhard in front, that I'll go fully parallel with the links.

 

[workingdog]

And now ... (drum roll) onto steering. Steering is mish-mash. EPS steering system in the cab, driving a manual steering box and old school pitman arm that has to transition to a 2020 Gladiator drag link.

So, routed out the pitman arm for the larger size TRE on the end of the drag link, cut the drag link in half to shorten in, and sleeved in a piece of pipe to restore strength.

Yes, I will weld it when I get it all together.

And all that yields the following geometry. I was told that the drag link needs to be pretty tight to the tie rod and panhard. That's why all the fancy bends. I think I need to move the front axle forward. Or, I need to move the steering box back and down a little, which causes other problems as the pitman arm is just short of the cross member and lowering it so it's under the cross member makes the TRE hard to get to and runs the steering rod into the motor mounts. All of which can be adjusted. This is one of those places where everything impacts everything else. These are the moments I wish for divine guidance.

So, as soon as I posted all this I realized what I need is a drop pitman arm. That would help the geometry a lot. Tomorrow I'll shorten and set the panhard and see how parallel they are.

 

[GLTHFJ60]

The reason you want your drag link/relay rod parallel to your tie rod is to reduce bump steer. The larger the difference between the two at static ride height, the worse bump steer will be.

Can't speak to link geometry, but I know that much, lol.

 

[DangerNoodle]

The angles and length are the things you need to match as closely as possible for the Panhard / drag link. Extra bends will just add weakness, especially in the tie rod. You want to try and get the two moving in a similar arc of travel horizontally, otherwise one may move father than the other as the suspension moves, causing bump steer. Matching them to the same vertical plane helps as well, as they will move in a more similar arc together.

 

[whitey45]

I ran straight lower trailing arms with the top links triagulated on one ton axles, 40 boggers, bbc, street driven for years and rubicon with no issues. Your rear should be good to go.

 

[Godfather90]

Another thing to remember is that it's the vector that passes through the two ends/heims that determines the geometry. Just because you bend the rod doesn't change the geometry.

 

[workingdog]

So, looking at the steering some more, I've decided it's all wrong. We made a bunch compromises that now were clearly for the wrong reasons. The front axle is too far forward, that pushed the steering box ridiculously far back on the frame horn. And the motor mount wasn't made to accommodate the steering shaft so the steering box is pointing way up in the air causing the pitman arm to be in a very strange location.

So, later today, I'm going to push the axle back 3" or so to match my 40 relative to the front cross member and the (more or less) bib. I'll move the steering box forward so it's in a more traditional position against the cross member, and I'll have to remove the front motor mount and rebuild the driver's side to create a hole for the steering to pass through. Moving the axle back will also move the panhard bracket behind the motor mount which will make life a lot easier. It's a very complicated area tight there with motor mount, panhard bracket, coilover tower, and bump stop all trying to live there. So, there's a couple of days work - but it should all fit and feel better after.

 

[workingdog]

So, in preparation for redoing the motor mount, I had to put the cab down so I could move the gantry forward to hold the motor up while I remove the mount. And while it was down I took some pictures of how it all sits together. Thank god it all sits where I expected. And I was able to verify there's plenty of room under the fender for a 2.0 x 12" coilover (5" up travel, 7" down travel). I could probably fit a 14", but I don't think I need that (5.5" up, 8.5" down). This ain't no desert racer.

 

[DangerNoodle]

A 12" Coilover is more than enough. you could probably get away with inboarding a 10" if space becomes an issue. 14" is a LOT of travel if you aren't crawling.

 

[workingdog]

I've decided to start painting the frame now, where I can while it's easy to get at - really should have painted the whole thing early one. Then I'll just have to do spot painting when I do the final welding. Since it's fresh steel, there's no need to use POR-15 Rust Preventive -right? I can just use POR-15 Top Coat after using their metal prep?

 

[Chuckha62]

I've decided to start painting the frame now, where I can while it's easy to get at - really should have painted the whole thing early one. Then I'll just have to do spot painting when I do the final welding. Since it's fresh steel, there's no need to use POR-15 Rust Preventive -right? I can just use POR-15 Top Coat after using their metal prep?

POR (Paint Over Rust) requires oxidation in order to work properly. On clean, new metal it doesn't work/bond as well.

 

[CreeperSleeper]

I would look into Steel-It.