Break over angle improvement

[Swarty]

Yeah, I guess there is no true 3-bar design.

How would a 3-link setup not need a trackbar? (same thing as a panhard bar correct?) How is the axle aligned side to side if it doesn't? Is the upper link triangulated more than what I am thinking in that setup?

Ah yeah, your right, now that I'm thinking about it every "3-link" I've seen without a track bar is actually a wishbone design. So it's got 4 contacts on one side or the other.

 

[Jetboy]

There are triangulated 3 link suspensions out there. But they're pretty few and far between. Probably for a good reason. It's just a wishbone offset to one side. It's doable, but probably not ideal because you need a really heavy cross member to handle the loads rather than putting them directly to the frame rails. I suspect this picture may not be super robust for offroading.

 

[Inv4drZm]

Tacomas get all the cool stuff. Still, it might be possible to adapt it to our trucks or at least steal their ideas. Notice the lower links mounted up into the frame.

Buggy Killer Kit - Rock Slayer - Tacoma 2005-2018 - 2nd and 3rd Gen ? Rock Slayer Off-Road

They also have a neat page explaining their 4-link system:

Why 4-Link? ? Rock Slayer Off-Road

 

[Jeffy]

Last time looked I thought I saw the tank attached to some type of frame mounts. But I need to look again. Raining and nasty out and tuck is out of the garage....


I may have given up though as the skid would have to be completely customized to take advantage of any upward movement. I'll look tomorrow and report back.

I would consider a 1/2" body lift but no more.... Even an inch overall would make a big difference as that darn gas tank is the #1 problem for me overall. The LCA mounts are next... I do have the RCI skids on the mounts... The help a little but not much in terms of getting up and over... More gradual ramping would just make it worse. They mainly just protect and are required...You have to bash really hard and I don't like that.. I find just about any contact as being bad.. gradual slopes may help a little.. but with the gas tank it already in full contact...

I don't think most people realize how just a small amount of contact will stop you.. The worse part is the gas tank will often pivot the truck in sketchy ways.

Getting back on topic a bit, I agree with you that any contact is bad, especially when it starts pivoting the truck as you can't really anticipate what's gonna happen at that point. My style is more moderate/ overlanding so I don't get into those situations much and I'm usually fine with a quick bump on some skid plates to get me where I want to go.

I've really wanted to lift the gas tank and I know it's been done successfully before (can't find a link now but I think it was Crozhawk on T120 who did it to his SAS 4th gen). However that's just a ton of work that I can't justify for a DD, especially considering I don't wheel too hard.

You have a rear bumper with your spare on it don't you? Have you considered using a different fuel cell tucked up under where the spare used to be? Might lose a bit of capacity but you can probably make it work. That should allow you to relocate the lower link inside the frame rail as well. Biggest downside would be shifting that much weight to the rear of the vehicle, past the axle. That could throw off the suspension handling a bit and you'd really have to consider that

 

[wfo9]

Just to clarify..

I don't want to change up the suspension design (well at least not right now). I would however like to gain some break over angle with a gas tank and LCA mount tuck.

I'm on another project at the moment... but when I have some time for the 4r again I'm going to see if there is any way to improve the gas tank skid clearance. It's my #1 limiter at the moment.

I clearly understand the truck has major limits and is not a good crawler platform... this is just always sort of a surprise hang up that I feel is just inches away from being in tune with the rest of the truck. Overall it works really good. this is sort of it's achilles heel at the moment.

 

[Jeffy]

I'm curious if a Tacoma tank would work under there, it seems they're tucked up a lot higher than ours. Shouldn't be too difficult to modify a tank skid to tuck up higher with it

 

[wfo9]

Just a follow up. Looked at the gas tank mounts.. and its all tied to the frame.. To get it higher with a body lift you would need to cut the lightweight cross members off the frame and re-weld them higher.. Looks like it would be a major PITA for very little gain and no removing of the bod lift ever.... Plus the gas tank skid would need to change to take advantage of it.

Looking at it further.. The main thing I would like to do is at least get the gas tank skid clearance better. That outter edge is the most beat up spot on the truck. This is also the most important clearance on the truck as this is where you typically place the tires on the highest spots in the line...

All the the gas tank skids I have seen are squared off here... And you lose a good inch or more of clearance since the actual gas tank curves in and sits further inside the frame rail in spots. I need to see if I can modify this skid to provide more clearance forward of the LCA. Or just buy another one if a better design exists. I want to take a close look at the c4 fab as it is the only one that looks very promising.. but if you know of others.. let me know. I have a RCI now.

 

[Jetboy]

I used the stock skid - and welded a sheet of 12ga steel to the bottom of. Making a skid plate 2 or 3 times thicker than the frame rails just doesn't make a lot of sense to me. I just plasma cut a pattern to fit and cutout most of the drain holes too. Then welded around the drain holes to secure it. It aint pretty, but it works.

Fits as close as the OEM skid and so far as taken a beating, but held up okay. The weak link is the OEM support brackets and I might firm them up a bit. For your use (harder than mine)- you should probably do that before really doing much else with it.. Otherwise I think starting with the OEM skid is going to get you as close to a form fit as you can. I've noticed mine is a lot tighter fit than a few aftermarket ones I've looked at, but I haven't seen all the aftermarket options. I'll see if I have a picture.

edit: you can see about how high it sits relative to the lower link frame mount on the lower right of the picture. It'll take a side pic to give a better idea of how it fits compared to the aftermarket ones with a better direct angle.

 

[Jetboy]

Here's a side view. It's basically just level with the lower link mount. It's higher than the transfer case skid though. That's my lowest point - and also removed right now for rebuild with more structure. I fit mine very tight and it flexed too much, so the next version of the transfer skid has internal gusseting.

 

[wfo9]

Yea, that was one of my first thoughts. Take a stock one and beef it up with more material.

I've already had to build new bracket mounts for the RCI as the ones it came with were just too weak and bent early on. I think I have 1/4 steel ones now. My gas tank skid has seen some major abuse... It's aluminum.. but the steel brackets all bent first. Now the aluminum is caved in in the center, but not worried as It is still protecting the gas tank well. It's slowly forming to the exact shape of the tank LOL.. But the corners will continue to hang out on the driver side.

 

[83Mule]

I think the C4 has a ton of wasted clearance in it from the pics I have seen.........

 

[BLACK-FL4RUNNER]

:hatsoff:

 

[Inv4drZm]

Did some measuring last weekend to plug numbers into the 3-link and 4-link suspension calculators online. Plugged mine into the 3-link and pretended the driver's side upper link wasn't there, and it said my lifted truck has 4% antisquat. By changing the length of the passenger's side upper link I was able to adjust the antisquat easily up to 60% or more if I wanted. I'm guessing, through changing my numbers down 3" (the amount of my rear lift), the stock AS of our trucks is around 40%.

It doesn't really matter because you can make the upper link mount adjustable for different AS% if you wanted. The importance of all of this is that it is very easy to convert your truck to a 3-link setup by gusseting the axle-side mount of the passenger upper link, change the stock link for beefier tubing, and maybe cut off the frame side mount to make the link longer if you want to get the AS back to stock.

Once you do that you can more easily raise the gas tank up by at least the amount of your body lift.