By request. My watts link tech

There are more than one approach to setting up a watts link correctly but I am going to try to make this as strait forward as possible...

here is a diagram of a basic watts link.

the red is the frame and notch
the brown is the rear end
the blue is the center link
the orange are the link bars
the green is the brackets

 

With the risk of sounding dumb - I have to ask how that still lets the rear end travel up and down? I have seen them before but never understood or used one.

 

The above diagram is shown at the center point of the suspension travel.
some "need to know" things about watts links and how to set them up:
1) the length of the link bars and the size of the center link predetermine the "usable" travel of the suspension. The shorter the link bars, the longer the center link will have to be to equal the same amount of travel of a link with long link bars and a shorter center link.
2) what ever the distance on center to center of the center link end holes (were the link bars attach) will have match the spread of the link bar brackets. In other words, when the suspension is center on its range of motion, the link bars have to be level and parallel with the ground.
3) either all the link ends have to have universal motion or the center pivot of the center link, but not both (it will bind). For example, if you use hime joints on the end of your link bars you need a bushing and solid Mount for the center of the watts link, or like my delivery you can use bushings on all the bar ends and a ball joint for the center link center pivot.
4) the link bars have to be the same length but the center link doesn't have to be the same lenght as the link bars
5) I almost forgot #5 LOL Don't assume that your 3rd member is centered between the wheels, its prob not. The center link center pivot has got to be centered in between the wheels

 

it works the same way a cantilever with a dogbone link would work. I will post pics of mine lifted, maybe in action it will make more sense

 

here is a pic of my center link. I have a iron worker at my disposal but you could make this out of a piece of tubing too

keep in mind I used a S10 upper ball joint as a center pivot

 

heres a good pic of the center link in action. You can see the mount for the ball loint isnt in the center of the 3rd member

 

heres what it looks like all the way laid out. you can also see one of the link mounts on the frame rail in this pic

 

here is a good behind the scene shot (don't worry it has shorter bolts now)

 

this is awesome... thanks for posting this!

 

The pic of it hanging just said a thousand words! What is the advantage over just a panhard bar? How do you know what the length of the center pivot needs to be?

 

Wow !!!

Looks good man

L

 

now I try to keep the center link around the same size as the 3rd member so that it is protected from road hazards. Another good tip is to make a mock up of your watts link out of cardboard and pin it to some wood at the link bar ends (the ones that would be attached to the frame) and use a sharpie in a hole at the center of the center link to tack its motion. You will notice the line it makes will "J" or hook at the end of its travel. That is not "usable" motion. measure just the strait part of the line, that will be your usable travel

 

Here is a picture of my setup. Similar but on top of the diff. This is just the chassis. With weight the linkages are parallel.

 

the biggest advantage is, you get no side to side "swing" from the axle. The center pivot should be as big as you can make it with in reason. I try to make it 9" center to center of the link bars, if the frame rails are real close together, it would need to be bigger

 

ya thats a great way to do it to. Like I said, I am trying to keep this simple so I didn't cover everything

 

I almost forgot. Because I used a ball joint as my center pivot and a ball joint shaft is tapered, I used a tapered reamer to make it seat right. You can get the reamer from speedway

 

Cool stuff thanks for the info!

 

So, is using the ball joint vs heim joints strictly a matter of personal preference, or is there an actual rhyme or reason to do it that way? I'm just curious, fascinated and can't wait to get to installing one for me!

 

I have found that himes will fail after time from dirt and grime. I don't know why I have this problem cuz I know they use them on tractors

 

anyone know where to buy the rubber bushings cheap?

 

www.grantkustoms.com