Bobbed m35 with air bag suspension

[cidrich]

West Coast, you can find these set up at any big truck junkyard. My friend had three of these trucks in his. The whole set up is used,spring hanger,spring,air bag,shocks,air leveler valve and all brackets.I bolted it to my frame and had to make plates and brackets for the pan hard bar.You have to torch everything off the freightliner because it is rivited on. It make a clean set up when done. I also used an extra air tank just for the air ride. You dont have too but I had it so I used it.

 

[MidnightDuramax]

Well I hope RHudson85 knows what he is doing. This is all stuff that can get people killed in a hurry. Two track bars/ panhard bars in opposite directions is just no way possible. It goes against all rules of physics and geometry. Having the panhard bar going the same direction and as close to the same angle as the drag link is correct. Death wobble is almost always caused by either worn out front end components or improper suspension and steering geometry. I am betting the caster is way off and the toe is probably out. that would cause your squirly steering. I am really interested to see pics of this when it is complete.

 

[RHudson85]

Mudguppy, I am curious to know why I cannot connect the knuckles together with a straight tie rod? Also have you tried to connect up a 1t box and the 3" ram? I have and suprisingly it works just fine together. PSC told me the same thing you did. After it ended up working I called them up and asked why they recommended against it and they told me the same thing you did, and then they said well if it works for you "more power to you".

Also the death wobble which is not like jeep death wobble where the whole axle is all over the place and feels like the truck is going to fall apart, but rather just a vibration. I presume is from a combination of out of balance tires (what a surprise) and an unstabilized axle from poor design of the panhard bar that C and C put on there. But this is just a guess, I do not think it is worn out components as I WAS TOLD the axle was a crate axle.

Eventually YES I am going to have both bars going the same direction (I stand corrected from the first statment I made on this thread about them going different directions), but I had to make one bar going to opposite direction for the time being with the drag link to see if I could even stop the frame from swaying back and forth on the airbags when the 1t box was used by itself. If I couldnt fix that then I was going to have to go back to the drawing board and come up with another steering system design.

 

[rlsnide]

Shop around before you just go out and buy this stuff i seen the systems anywhere from $1000 dollars to $1700 dollars just for one axle setup. I looked around for many weeks and found the whole setup off a 95 frieghtliner for $200 locally. The guy I bought it from also cut everything off and had it waiting on me on a pallet when I got there and chipped in two air ride seats for me also for that price. The only thing I had to get was bags I could have used the ones that it came with but they were a little dry rotted.

 

[Deucemedic]

Ok guys sorry i havent postedin a while but i was out of town for a and am finally back. Ill post pics tonight of what is done already. Does anyone have any of their own airride system? also its been hot as heck here so we haven't worked on it for 3 weeks. Again pleas post any airride pictures if u have especially the fronts

 

[mudguppy]

Mudguppy, I am curious to know why I cannot connect the knuckles together with a straight tie rod? ....

a center-mounted double-ended ram with individual tie-rods going to each steering knuckle creates a varying overall distance between the two steering knuckle arms. and a straight tie rod obviously keeps a uniform distance. bolt these two systems together and you'll get mechanical bind as the system is cycled. you may not notice it, but you're likely binding at full right/left.

... Also have you tried to connect up a 1t box and the 3" ram? ....

no. why would I? and, i'm pretty sure i mentioned this a long time ago, but i personally believe a 1T steering box is severely inappropriate for a medium duty truck. let's face it: you've got as much weight on just the front axle of your truck as most 1T trucks weigh in their entirety.

... I have and suprisingly it works just fine together. ....

i, too, am also surprised. however, if you thought it was a good idea, then why were you surprised that it worked?

... PSC told me the same thing you did. After it ended up working I called them up and asked why they recommended against it and they told me the same thing you did, and then they said well if it works for you "more power to you". ....

cool. then more power to you.

... Also the death wobble which is not like jeep death wobble where the whole axle is all over the place and feels like the truck is going to fall apart, but rather just a vibration. I presume is from a combination of out of balance tires (what a surprise) and an unstabilized axle from poor design of the panhard bar that C and C put on there. But this is just a guess, I do not think it is worn out components as I WAS TOLD the axle was a crate axle. ....

don't take this the wrong way, but i think your truck has serious design problems and should be considered unsafe for public road use. C&C did a horrid job on both the design and fabrication of the front suspension as noted by both the wander and death wobble/vibration. and your steering arrangement is likely not nearly as compatable or robust as you believe, regardless of how well it feels like it's working.

 

[cj360trider]

here are some long awaited pics of the current threads build. apologies for taking so long

 

[cj360trider]

the bed being cut down

 

[cj360trider]

the rear of the bed welded back onto shortened bed. it was more than just tac welded. i just do not have a pic of it yet. D-Med is working on getn it sand blasted so it can be painted.

 

[Ford Mechanic]

Mudguppy, I am curious to know why I cannot connect the knuckles together with a straight tie rod? Also have you tried to connect up a 1t box and the 3" ram? I have and suprisingly it works just fine together. PSC told me the same thing you did. After it ended up working I called them up and asked why they recommended against it and they told me the same thing you did, and then they said well if it works for you "more power to you".

Also the death wobble which is not like jeep death wobble where the whole axle is all over the place and feels like the truck is going to fall apart, but rather just a vibration. I presume is from a combination of out of balance tires (what a surprise) and an unstabilized axle from poor design of the panhard bar that C and C put on there. But this is just a guess, I do not think it is worn out components as I WAS TOLD the axle was a crate axle.

Eventually YES I am going to have both bars going the same direction (I stand corrected from the first statment I made on this thread about them going different directions), but I had to make one bar going to opposite direction for the time being with the drag link to see if I could even stop the frame from swaying back and forth on the airbags when the 1t box was used by itself. If I couldnt fix that then I was going to have to go back to the drawing board and come up with another steering system design.

for starters i agree with mudguppy and others the criss crossed panard bars are a dangerous issue waiting to happen. the issuse with the hydro i am not familer enough with to comment on, but just a thought is that in some states arn't a full hydro system illegal? I'm fairly certin it is in NC?

But if the body sway is what you are trying to fix why not fab up a sway bar? you obviously have the tools and materials needed to do this?

this is the best pic i could find of one in a hurry. the big black round bar is the sway bar on this vehicle. heavy duty trucks have the same basic set-up. the ends bolt to the axle, (or lower control arm in this case) the closer to the knuckle the better and then the middle of the bar bolts to the frame.

this is probably what the other person was talking about when they said they had a torsion bar on the truck being that it's still the same basic design.

 

[RHudson85]

I am just going to say no comment on some of the comments that have been made.

Fordmechanic, yes you are right sway bar is a good idea. I have a sway bar already, and it does a pretty good job of fixing body roll while driving. One problem is the the links on the sway bar are only made of 1/2" heim jts and on top of that the mis-alignment is already maxxed out therfore I have bent a few and broken 1 heim. With my steering design which is nearing completion I have re-designed the sway bar to include 3/4" heim jts and to have plenty of mis-alignment to either side. I'm really looking forward to being able to give it a test drive.

As far as the sway I was talking about, on a straight axle vehicle where the steering box is mounted on the frame and swings left to right, the steering gear will pull the vehicle back and forth in relation to the axle. That is where the extra panhard bar comes in. I plan on making some future changes to the design, but for the time being I will need to see how it drives.

Yes, you are also right, the criss cross panhard bars are not the best design, however has anyone everheard of the "Watts Link" its a suspension used on some race cars as well as some OEM designs. It uses the same concept of criss-crossed panhard bars but is much more compact.

I began bolting everything up last weekend, I ran into a few small problems that I believe I have worked out, I just have to bolt everything back up and continue forward.

 

[mudguppy]

... however has anyone everheard of the "Watts Link"...

yes, and what you have is not a Watt's linkage.

i'm sorry you don't like the feedback you've received. the things i have said and comments i have made are not personal, but rather from an engineering and avid designer/builder perspective.

i hope it all works out for you. i really would like to help you fix your truck the way it should have been from the get-go. please let me know if you would like any more perspectives or would like to discuss further - really.

 

[plym49]

I am just going to say no comment on some of the comments that have been made.

Fordmechanic, yes you are right sway bar is a good idea. I have a sway bar already, and it does a pretty good job of fixing body roll while driving. One problem is the the links on the sway bar are only made of 1/2" heim jts and on top of that the mis-alignment is already maxxed out therfore I have bent a few and broken 1 heim. With my steering design which is nearing completion I have re-designed the sway bar to include 3/4" heim jts and to have plenty of mis-alignment to either side. I'm really looking forward to being able to give it a test drive.

As far as the sway I was talking about, on a straight axle vehicle where the steering box is mounted on the frame and swings left to right, the steering gear will pull the vehicle back and forth in relation to the axle. That is where the extra panhard bar comes in. I plan on making some future changes to the design, but for the time being I will need to see how it drives.

Yes, you are also right, the criss cross panhard bars are not the best design, however has anyone everheard of the "Watts Link" its a suspension used on some race cars as well as some OEM designs. It uses the same concept of criss-crossed panhard bars but is much more compact.

I began bolting everything up last weekend, I ran into a few small problems that I believe I have worked out, I just have to bolt everything back up and continue forward.

have you considered the possibility that you are bending and breaking parts because you have a healthy dose of interference motion? Of course the weak link in the chain is going to break. Streghtn those components, and something else will break: maybe something a lot more expensive (or unsafe).

Respectfully said, again as others have, you owe it to yourself to put that thing right. The last thing you want is to gather notoriety because of an accident or someone seeing your vehicle, taking cell phone photos and posting it on a 'ghetto engineering' thread.

I am sorry if that sounded preachy. If it did, it was not my intent; it is only my limited skills in expressing myself. We are with you and the suggestions offered have been in good faith.

 

[RHudson85]

THe only "Ghetto Engineering" and breaking things, was from when the truck was built. Think about it.........You cant expect a sway bar link built out of 1/2 heim jts to actully hold on a 12,000lb vehicle. My daily driver Ford Ranger that weighs 3500 lbs has 1/2" (excuse me I mean 13mm) bolts for the sway bar links.

Let me also add that the current Panhard bar on the truck sets on top of the axle top loader when the truck is down. Over time this has caused it to be slightly bent. Im actually over here laughing at what a poor design it is but oh well, just more for me to fix.

Just so you get an idea of how "Heavy Duty" the original sway bar links were, I have attached a pic.