Changing the suspension on my dually???

[monte0185]

Hey guys and gals. I have a question. This is my suspension at the moment. I was wondering If i could take some square tubing and cut a hole in one end and weld a tube inside it and put spring bushings in then replace my springs with it on each side. Somehow bolting it to the axle and keep my air bags in place or actually replace with bigger ones and then put a watts link behind the axle. I dont want to cut my frame and im not looking to lay frame or anything like that. I just want to maybe tuck the top inch or so of the tire and that would be fine. Mainly looking to lower it a bit more and improve my ride a bit. Just curious if its a stupid idea or not. Oh and the tires on the back are only 27" tall. gonna be swapping in 30.5" or 245/75/16. So any suggestions and pics would be great. Im gonna be pulling a 5th wheel or GN camper so I really dont wanna mess with the frame and bed at all. I use my truck as a truck.

[slotard]

So you're looking to raise the front spring mount? You can buy mounts designed for that: http://www.andysautosport.com/hanger...ruck/1982.html so I imagine if you do a good job at DIYing one there won't be a problem. It will change your pinion angle so watch out for that - you may have to play with the shackle to make it point where it should.

[nonstop]

Are you talking about a home made trailing arm suspension, replacing the springs with tubing? If so, I think you may be safer buying a kit, so the engineering has already been done and you know it works, especially if you are talking about towing with it. Not to discount any fab skills on your part, but why reinvent the wheel.

[SCOTI]

Sounds like you're describing a 2-link......

[monte0185]

Yeah pretty much. I was just looking at 75Dually's thread on his page and he did pretty much what i was thinking but I was thinking of running the bars on top of the axle instead of underneath and doing my gags on the side of the frame like they are but with beefier mounts and maybe a pan-hard bar or watts link.

[monte0185]

Originally Posted by slotard

So you're looking to raise the front spring mount? You can buy mounts designed for that: http://www.andysautosport.com/hanger...ruck/1982.html so I imagine if you do a good job at DIYing one there won't be a problem. It will change your pinion angle so watch out for that - you may have to play with the shackle to make it point where it should.

I already raised the front spring mount with a beltech kit. Just haven't added the rear shackle yet. wanted to get the right size tires first.

Originally Posted by nonstop

Are you talking about a home made trailing arm suspension, replacing the springs with tubing? If so, I think you may be safer buying a kit, so the engineering has already been done and you know it works, especially if you are talking about towing with it. Not to discount any fab skills on your part, but why reinvent the wheel.

Id gladly buy a kit if someone made them for a dually. all the ones I have seen were home made or shop made from scratch. Im just trying to think out of the box a bit to see if i can improve my ride quality some and not hinder my towing or box capacity in anyway since i use my truck to haul everything under the sun.

[nonstop]

After seeing the picture, it seems to make more sense now. Just curious though about stability while towing, or will the watts link take care of it?

[monte0185]

Originally Posted by nonstop

After seeing the picture, it seems to make more sense now. Just curious though about stability while towing, or will the watts link take care of it?

Watts link or panhard bar will take care of any side to side movement. Its basically a trailing arm setup from the 60's trucks with shorter arms and not triangulated.

[monte0185]

Basically this only with the axle underneath the bar.

[SCOTI]

Originally Posted by monte0185

Watts link or panhard bar will take care of any side to side movement. Its basically a trailing arm setup from the 60's trucks with shorter arms and not triangulated.

While they both have 2 links, that's about the total similarity. What you're wanting to do (where you want the links to go) is going to make the links super short (OE front leaf hanger mounting location).

The truck-arm 2-link arrangement allows for articulation because of their length (51+"L, I-beam construction (allows twist), & triangulation (twist & articulation). A short bar 2-link arrangement does not allow that articulation.

[monte0185]

Originally Posted by SCOTI

While they both have 2 links, that's about the total similarity. What you're wanting to do (where you want the links to go) is going to make the links super short (OE front leaf hanger mounting location).

The truck-arm 2-link arrangement allows for articulation because of their length (51+"L, I-beam construction (allows twist), & triangulation (twist & articulation). A short bar 2-link arrangement does not allow that articulation.

Well yeah I agree there but do you need twist and triangulation for everyday driving or towing a big trailer? I could see it if i were going off road but the most dirt this truck sees is where its parked at. LOL. I would think even with the short arms the bags would flex enough to keep anything from breaking.

Now its entirely possible im wrong. I am not an engineer by not means so please tell me. Thats why im asking if its a dumb idea or not.

[SCOTI]

Originally Posted by monte0185

Well yeah I agree there but do you need twist and triangulation for everyday driving or towing a big trailer? I could see it if i were going off road but the most dirt this truck sees is where its parked at. LOL. I would think even with the short arms the bags would flex enough to keep anything from breaking.

Now its entirely possible im wrong. I am not an engineer by not means so please tell me. Thats why im asking if its a dumb idea or not.

The bags don't really enter into the equation. The links do....

Raise one wheel higher than the other & anything positively attached to it is going to want to follow the same arc. The end attached to the rear will follow but what about the opposite end @ the hanger? What happens there?

So in the real world.... your app would be short links positively mounted @ the rear-end housing & firm bushings approx 25" away. Picture turning right into a parking lot from the street where there's a slight incline as you transition during the turn. The right side is going to need to lift while the left is going to squat while turning. While not off-roading, there will be some serious stress on the front mounts. The short, fixed position bars won't allow much twist so the front mounts will be where the stress is focused.

[monte0185]

Originally Posted by SCOTI

The bags don't really enter into the equation. The links do....

Raise one wheel higher than the other & anything positively attached to it is going to want to follow the same arc. The end attached to the rear will follow but what about the opposite end @ the hanger? What happens there?

So in the real world.... your app would be short links positively mounted @ the rear-end housing & firm bushings approx 25" away. Picture turning right into a parking lot from the street where there's a slight incline as you transition during the turn. The right side is going to need to lift while the left is going to squat while turning. While not off-roading, there will be some serious stress on the front mounts. The short, fixed position bars won't allow much twist so the front mounts will be where the stress is focused.

Ok I gotcha. Then how would one fix said issue? 4-link? Or would the stress be enough to worry about the frame mount breaking? 75 dually did basically the same thing??

[SCOTI]

Originally Posted by monte0185

Ok I gotcha. Then how would one fix said issue? 4-link? Or would the stress be enough to worry about the frame mount breaking? 75 dually did basically the same thing??

He removed the saddle tanks on his truck. With them gone, the hangers could be relocated. What length are his bars?

I'm also pretty sure he mentioned somewhere in his build thread about wanting to do a 4-link....

What is the issue w/the leaf/AOL set-up you currently have?

[monte0185]

Originally Posted by SCOTI

He removed the saddle tanks on his truck. With them gone, the hangers could be relocated. What length are his bars?

I'm also pretty sure he mentioned somewhere in his build thread about wanting to do a 4-link....

What is the issue w/the leaf/AOL set-up you currently have?

I didn't realize that's why he moved his tanks to a single rear tank. Makes sense though. As far as mine there is Nothing really wrong with it. Bags are old and could use replacing but overall its ok. I was just looking at this for ride quality more than anything and maybe update it a bit.

I guess I could do a beefy 4 link and use this type on the rear of the axle kinda like a drag car setup only on the outside of the frame. Then I would have to cut spring hangars off and all that jazz.

[monte0185]

Found this as well. this could work nicely.. I think I would need bigger bags however.. http://www.ridetech.com/store/universal-hd-4-link.html

[SCOTI]

Originally Posted by monte0185

Found this as well. this could work nicely.. I think I would need bigger bags however.. http://www.ridetech.com/store/universal-hd-4-link.html

The bags that come w/the HD kit are what you would need. Their older 'bolt-in' kit is what I started with & tweaked things for my targeted ride height (my ride height is their air'd out height).

I'm not sure if 75dually moved his hangers forward or not. You can prob find that info in his thread or send him a PM & ask him to verify.

[Junkpyl]

Not trying to hijack the thread but I'm getting ready to do the same thing to my 72 C30 Dually. Need to bring the axle forward a couple feet so a regular 8' bed will fit on it. Any progress on your truck? I was thinking rod ends to compensate for the articulation and maybe a triangulated arm to attach to the top of the rear axle.

[monte0185]

Originally Posted by Junkpyl

Not trying to hijack the thread but I'm getting ready to do the same thing to my 72 C30 Dually. Need to bring the axle forward a couple feet so a regular 8' bed will fit on it. Any progress on your truck? I was thinking rod ends to compensate for the articulation and maybe a triangulated arm to attach to the top of the rear axle.

No I haven't done anything. Been too cold and Bertha won't fit in my garage. I lack about a foot. Lol