Truggy - where does tube start?

[T1000]

I currently have a 4Runner that I chopped into a truck.

Eventually, even after all the work I've done getting it to look good, I will chop the bed completely off and truggy it. I should've done that in the first place, but things just didn't work out that way...you know.

When you do that, I guess you cut the frame rails, cap them with plate, and then weld tube to it.

That's all fine, but where else does it connect to the frame?

That can't be the only spot?

 

[T1000]

Nobody?

 

[Mo Rocks]

I am not sure exactly what your question is.

Where else does "what" connect to?

Are you asking what places on the frame does the roll cage/tubing connect to ?? if so, then that depends on what you are working on, what your intended use is, personal preferences,etc

There are a zillion threads on fabrication and tube bending/cutting, etc. here on MUD.

I am not an expert in fabrication, but seach the threads on truggy, roll cage fabrication, tube bending, etc.
You will get more info than you can absorb.

I hope this is a little help.

Just my $.02 worth

 

[Sputnik40]

If you mean where do you cut the frame to do a proper 4-link - there are several FJ40 build threads on here that may help.

Kinda guessing, but I'd basically take my desired wheelbase, establish my ride height, calculate link location/length, and then cut the frame and mount a cross member that clears the driveline while providing a mounting point for your frame side links.

There's a 4-link calculate on Pirate somewhere that's helpful.

 

[Mace]

go buy a frame and build a buggy.

You will be happier in the end.

 

[Mo Rocks]

I am not sure exactly what your question is.

Where else does "what" connect to?

Are you asking what places on the frame does the roll cage/tubing connect to ?? if so, then that depends on what you are working on, what your intended use is, personal preferences,etc

There are a zillion threads on fabrication and tube bending/cutting, etc. here on MUD.

I am not an expert in fabrication, but seach the threads on truggy, roll cage fabrication, tube bending, etc.
You will get more info than you can absorb.

I hope this is a little help.

Just my $.02 worth

Just to quote myself here.
I obviously did not understand that you were talking about doing a 4 link rear suspension !!!!!!
I thought you were talking about building a cage :whoops:

4x4 TV or whatever they call that show just had a section on the different types of 4 links. They said that the double triangulated 4-link was now the most popular. It offers the most flex w/o binding....but you have to know what lengths to run your tubing.
Another FYI from the show was that the Johnny Joint rod ends were the best because they are rebuildable...just a little more $$$


Good Luck.

 

[T1000]

I meant just the frame in general, but I do plan on doing four link suspension. I have that calculator and everything.

I guess I just was trying to figure out where else exactly you tie the cage into the frame, besides just the ends of the frame rails.

 

[Isotel]

I meant just the frame in general, but I do plan on doing four link suspension. I have that calculator and everything.

I guess I just was trying to figure out where else exactly you tie the cage into the frame, besides just the ends of the frame rails.

Its all up to you really, this is where you need to get creative. Truggys look cool as hell if the tube is done right, and like Poo if not. What type of Suspension are you thinking? what part of Co are you in?

 

[T1000]

Its all up to you really, this is where you need to get creative. Truggys look cool as hell if the tube is done right, and like Poo if not. What type of Suspension are you thinking? what part of Co are you in?

I was in Colorado Springs, now I'm moving to Flo-Rida.

I'm thinking I'm gonna end up doing a four link in the rear for sure, not sure about the front since steering and that pesky engine make things a lot more complicated...Maybe a three link setup. IDK...

 

[BellyDoc]

Once you decide to start chopping and welding on the frame of your vehicle, all bets are off. You can do anything you want.

If you're looking to do a double triangulated 4 link in the rear, then you should start thinking about it by reading up on 4-link designs, choosing the axle and coilovers, and then plugging some candidate designs into a "4-link calculator" of which there are a couple of versions. Then after that, you'll be able to design the amount of ride travel and twist that your suspension is going to accommdate.

The shape of your tube chassis will (among other things) have to fit in between where the wheels articulate, and will have to clear above where you design the links to end up at full compression.

When you ask where the frame should end and the tube should start, the answer then becomes clear. The frame should end, and the tube should start at a point pretty darn near where your links mount to the chassis. The reason for this is so that you can build in the clearance you need above the links.

There's a huge amount to learn about linked suspensions. It's a deep topic.

 

[T1000]

It is...I have a couple of calculators, and I don't think the rear triangulation (with coilovers, skipping leaves) is going to be too outrageous to figure out (I'm just using a Toyota 8" rear axle I think, unless I go with a Diamond...) but I feel like the front is going to be much more difficult due to steering.

 

[BellyDoc]

The biggest issue with the front is that you have to make some choices about the way the links work relative to the driveshaft, the transmission and the oil sump.

First off, I'd recommend that if you're going to link up and coilover your suspension, you go to bigger axles with more width. This will buy you room to upgrade the size of tires (based on stronger axle shafts and ring gears), AND it will improve your ability to angle the links.

In the rear (with a cented rear t-case output and an offset front), it's easy to bring the lower links to a well supported crossmember point on center below the rear output of the transfer case. Because of this, the driveshaft isn't going to contact any links. In the front, the lower links typically CAN'T go to a center point unless you're willing to build in an extra low hanging crossmember. Many people attach the lowers to the frame rails. This isn't a lot of "triangulation", and so the side-to-side support of the axle depends much more on the upper links. Additionally, you now have the driveshaft crossing over the lowers and crossing under the uppers. You have to make sure not to build them close enough together that the links touch the driveshaft when the suspension twists!

The uppers pose their own challenges. You have to find a point as wide as possible to mount them to the chassis. You also need some vertical separation above the lowers. However most importantly, you need them to clear the sump.

One way would be to mount them wide on the axle, but this compromises the strength of the triangulation. Another way would be to bring them in close to center on the axle, but then limit uptravel so that they don't go high enough to hit the sump. A lot of people don't like this option because they're trying to limit an unnecessarily high center of gravity. Some people make curved links, but that makes it very hard to use the standard opposing threaded rod ends for adjustment. My compromise solution was to run the front axle forward enough to make the links clear. I got great suspension compression geometry, but I bought a long wheelbase.

Don't forget that a double triangulated 4 link front suspension obligates you to run fully hydraulic steering. If you want to run hydro ram assist, standard power steering or purely manual, you're going to need a cross-over drag link and tie rod which is incompatible with the motion inherent in 4 link designs. Any of these are compatible with a front panhard bar for side-to-side stabilization, and then if you use one, you no longer need triangles. At that point, you're free to use a 3 link system against axle wrap or even *gasp* radius arms!