Suspension ideas...need input please

[juddski88]

A little OT...

Well I can't get the pic to link overhere...anyway look in "Spurs_442" garage over at TDP. His housing spun on the tubes. Initially I was thinking that a snubber would have stop this...but the more I think about it, the less I think it would have help in his case. FYI, he has a dually and did this sled pullin'

why don't you think it would've worked? i mean, could it have reduced the stress on the assembly and not allowed them to break free at all

 

[The Neens]

His housing spun on the tubes. Initially I was thinking that a snubber would have stop this...but the more I think about it, the less I think it would have help in his case.

why don't you think it would've worked? i mean, could it have reduced the stress on the assembly and not allowed them to break free at all

Pretty common for that to happen on 10 and 12 bolt Chevy car/truck housings with hard launches...The tubes are pressed in from the factory, the mod was to weld them to the center section...I don't know much about our current housings, that's the 1st time I've heard about tubes rotating...

 

[malibu795]

Pretty common for that to happen on 10 and 12 bolt Chevy car/truck housings with hard launches...The tubes are pressed in from the factory, the mod was to weld them to the center section...I don't know much about our current housings, that's the 1st time I've heard about tubes rotating...

factory is pressed and spot welded on roughly 1"dia for spot 90* increments. IIRC the 1150AAM are the same way for the most part all stock OEM axle are that way. any aftermarket is welded all the way around

 

[WanaDmaxsub]

why don't you think it would've worked? i mean, could it have reduced the stress on the assembly and not allowed them to break free at all

Good point.

 

[TheBac]

Got the truck up on the lift at Eric's on Sunday and did some measuring and idea-tossing.
Frame crossmember is just too far forward of the pinion to be of use. Darn it.
So the snubber will have to be bolted to a "platform" that spans two of the under-bed reinforcements. 22" total length. Maybe use a U-shaped bar about 6" wide?

Eric thought Mike's idea of a platform was a good one. He thinks something could be bent to run up and over the pinion "balancer".

Distance between bottom of bed and front of diff behind the "balancer" - 13.5". So I dont think there will be any issue with suspension hitting snubber when its retracted.

On to building the thing....

 

[SteveFord]

Cool Tom keep us updated!

 

[Diesel Pilot]

Are you guys talking about a design like came on most Mopar's?

I have have an adjustable pinion snubber on my Barracuda and it does a good job of helping axle wrap to a certain extent, it also does a very good job of pushing the rear of the car up in the air. So I guess the pinion is still turning a bit while the rear is coming up.

 

[TheBac]

Are you guys talking about a design like came on most Mopar's?

I have have an adjustable pinion snubbed on my Barracuda and it does a good job of helping axle wrap to a certain extent, it also does a very good job of pushing the rear of the car up in the air. So I guess the pinion is still turning a bit while the rear is coming up.

Yep. IMO, the bonus of the rear coming up is twofold.

1) the rear axle is being forced downward, planting the rear tires
2) the rear body raising will force weight back to the front of the truck, helping plant the front tires.


Guys, in your opinions, would the bed floor be strong enough to handle holding this setup without flexing/bending upward?

The plan is to use a 1/4" plate for the snubber itself, but that would then be bolted to the bed. I could use the old G/N hitch mount holes in the bed for the mount points.

Also, today I figured out a way to build this without using any welding. Just have to flesh the idea out a bit more.

 

[TrentNell]

Yep. IMO, the bonus of the rear coming up is twofold.

1) the rear axle is being forced downward, planting the rear tires
2) the rear body raising will force weight back to the front of the truck, helping plant the front tires.


Guys, in your opinions, would the bed floor be strong enough to handle holding this setup without flexing/bending upward?

The plan is to use a 1/4" plate for the snubber itself, but that would then be bolted to the bed. I could use the old G/N hitch mount holes in the bed for the mount points.

Also, today I figured out a way to build this without using any welding. Just have to flesh the idea out a bit more.

the bed floor may hold with the plate that will be bolted to it but i would still stick with the cross members or build a new cross member just for the snubber , if it didnt hold it would f#$% up your bed, and i dont think anyone can guess how much stress will be put on the snubber could be very little or a whole lot , just my opinion though i have never ran a car with one .

 

[TheBac]

Well, I figure the bed has all those channels in it to strengthen it.....
Only way to find out is to try it.

So I'm going to use a 1/4" plate for the "mount". Bolt that to the old G/N holes. Probably larger than 12"x16". Gonna have to work that.
Use a 2" floor flange for the snubber mount, bolted just ahead of the G/N mount holes.
Use a ~9" length of 2"OD pipe for the body, threaded into the floor flange.
Use a ~9" length of 1-1/2"OD pipe for the extention. (or whatever size pipe fits snugly into the 2"OD body)
Use a simple pipe cap threaded onto the end of the extension for the snubber mount. Drill hole into cap and thread snubber through it.
Drill holes accordingly for length to diff and minor adjustments.

Tricky part is making the pad for the differential. Going to have to make a cardboard model of it first.

I hate working in a cold garage. :rofl:

 

[RENODMAX]

Tom let me know if you need any help with other stuff. I have lots of pictures and whatnot of trucks weve setup around here.

 

[othrgrl]

The only downfall I see to the snubber idea is that you will still have axle wrap - you will just be utilizing the force of the axle wrap to plant the rear tires and lift the back end, but the pinion angle will still be changing (otherwise you wouldn't get those affects). Also if you try to run traction bars and the snubber the traction bars will prevent axle wrap and then the snubber won't come into play. Just how I'm picturing everything working - I could be wrong.

 

[TheBac]

Its been my understanding that a snubber should do a good job of transferring the axle wrap into downward force while at the same time not allowing excessive weight transfer.
I look at it this way....the only way we'll ever find out is to build one and test it. Nobody else has. I do not know why that is. You'd have thought someone (suspension company) would have at least tested something.

As an aside, I took a break today and talked to the fabricator on my route. He listened to my ideas, thought for a bit, then said, "I've got another idea." He proposes to use a 1" threaded rod connected to a 1"x2" crossmember (connected to the truck frame) via a piece of pipe and two jam nuts. The snubber itself would be threaded in to the end of the rod. He told me it would be easy to build, I just have to make some frame measurements for him.

Theres a reason I drive a brown truck for a living....:rofl:

 

[malibu795]

Its been my understanding that a snubber should do a good job of transferring the axle wrap into downward force while at the same time not allowing excessive weight transfer.
I look at it this way....the only way we'll ever find out is to build one and test it. Nobody else has. I do not know why that is. You'd have thought someone (suspension company) would have at least tested something.

As an aside, I took a break today and talked to the fabricator on my route. He listened to my ideas, thought for a bit, then said, "I've got another idea." He proposes to use a 1" threaded rod connected to a 1"x2" crossmember (connected to the truck frame) via a piece of pipe and two jam nuts. The snubber itself would be threaded in to the end of the rod. He told me it would be easy to build, I just have to make some frame measurements for him.

Theres a reason I drive a brown truck for a living....:rofl:

i was just about goign to mention somethign similar to that much like a traction bar works but verticle instead of horitzontal im look for a pic will post later

similar to this but with more sliding ability

 

[mytmousemalibu]

I'll bite too....
Im going to be digging into this too soon. Somthins gonna hafta be done on mine after i get "plan-b" in effect
We,ve been drag racing for quite a long time and the traction debate is as old as the sport. There some simple thoughs id like to add...

Say a 2wd...
Like Redbone has been talkin about the instant center...your point of lift leverage on the chassis the shorter it is the more "violent" its action, this can net you good 60' and nice hard launches but its also hard on components, it also places increased shock load on the tires that can make breaking traction easier, it can also load up and unload the suspension and act "rubber bandish". A longer instant center is more soft in comparison but will also be softer off the line, this might be more advantagous on a 4x4 keeping from from too much weight transfer and keepin the front tires planted. If they spin its wasted energy even with the rear hooked. Like someone mentioned the Mopar launch...when thoes cars launch and the whole car jumps up, thats Anti-squat, your best friend! Of course the 4-Link is one of the best drag suspensions but often not in the cards for us. Well you can devise a poormans 4-link called the Leaf-link if you can devise mounting and braketry it uses the front section of the leaf as the lower link. Ladder bars are old school but they work, just not too good with leafs, like said, leaf-floaters are needed to eleminate bind but floaters are an open moving component and would be a bad choice for anything than deticated track use. The traditional long traction bars beeing built for a while arnt all that bad IMO if your stickin to crappy leaf springs, even better preloaded. I honestly dont see an advantage of a pinion snubber exept appling rotational resistance directly to the housing. And if used with bars, its more or less going to act like a suspension compression stop. But in the instance of anti-squat (which you really want) where the distance between the pinion and the bed should grow larger rendering it useless. And only a snubber is just a slapper bar with less mechanical leverage. Ive been thinking About doing a long version of a Slide-a-link (adam posted a pic) as a good alternative. One other idea without the complication of a 4-link and lots of serious fab work is to make a trailing arm set-up! (think C-10 chev truck susp.) Removing the leafs in favor of good/cheap coil-overs like Afco's, and mount the arms solidly to the leaf pad on the axle. the trick is they would need a crossmember welded in to mount to if you follow Gm's design and triangulate them to the vehicle center. This way does a decent job of keeping the axle located side to side. The other way would be to mount to the outside of the frame, via custom mounts. This manner would require a track locating device like a panhard bar or watts linkage. The beinifit of this setup is there is exellent anti-squat and zero axle rotation/wrap, very simple and strong. It works so good Nascar still uses it. Still some fab involved but not as bad as a 4-link. Just thinkin out loud! :hug:

 

[juddski88]

the problem with a coilover setup though is that it's not good for towing for us DD folk

 

[mytmousemalibu]

Well ita be more of a pain but you could use standard coil springs and mountings an an adjustable shock. IMO anything stout enough to do any towing is gonna be pretty stiff like stock leafs. One idea around this...not the cheapest but airbags...or just add assistance bags to tow, could be made to be easily removabe, dont even need to have compressor and tank and crap, just air lines. And the trailing arm setup properly done could be brute strong so no issues there!

 

[mytmousemalibu]

I was thinkin today and i kinda overlooked somthing on the pinion snubber. In the case if anti-squat ie, your best friend, the distance between the snubber and contact point wants to grow and thus forcing tires into the pavement harder but i overlooked that under lots of weight transfer like a hi-power car like a pro-mod, still haaving anti-squat it will still compress the rear suspension. so a pinion snubber would work but at this point with proper suspension and tuning of it, it kinda makes it just a susp travel stop. I see anti-rotaton advantages of it to be small, main benift is its applied to the pinion and could reduce some stress on the axle housing, is it a worthy amout or neglible, i dunno? And also, say its set stop rotation, compression at a given measured distance, it might not achive the same distance of compression each pass due to conditions...if theres a gap it can give it the opportunity to axle wrap, not enough compression distance is gonna contact early and stop suspension travel making it a more or less solid susp. Im not tryin to shoot down ur ideas or anything, im just as intrested in the best possible setup as you guys, i just see it as, why do with a pinion snubber what proper traction bars and or suspension design can achive more efficiantly? I'd sure be intrested in test results and would love to be proven wrong:hug:

 

[TheBac]

Interesting post in Chassis concerning shocks: http://www.duramaxdiesels.com/forum/showpost.php?p=78131&postcount=51

So running the Rancho9000's set fully stiff on all 4 corners like Jess said is the way to go there?

 

[TheBac]

Alright...NO laughing at my wood working skills!

We finally had some over 40* weather here, so I was able to get under the truck and look around.
1st thing I found out was the using the G/N crossbar and threaded rod wouldnt work. Turns out the fuel tank is in the way. Now how inconvenient is that? Even if I placed the crossbar on the top of the frame it wouldn't work, because then there'd be nowhere for the threaded rod to go, so it'd always be extended onto the pinion.
2nd thing I found was that I possibly COULD run a support from the crossmember in front of the diff, back to the box support behind the diff. Then I got thinking that the box support may not be strong enough. So that was out.
I looked back at that front crossmember and got thinking how I could go back to my original idea of using that.
So I took the snubber and screwed it into a dowel to get an idea of where exactly the top of the rod would be. To my surprise, it was only about 3-1/2" from the front crossmember. Since I cannot fab with metal, I made a mockup with wood. I figure the metal shop can make the "stand" out of 1/4" steel, and we could either weld it to the crossmember, or maybe use Ubolts? The rod mount would have to be a tube of some kind, with the snubber mounted to a rod that can be extended and retracted. I ran the snubber into the space behind the balancer on the pinion snout, and there is about 1/2" of clearance. I think Mike's idea of a sheetmetal "shield" that the snubber would rest on would be a good idea.

Opinions? Ideas? Am I FOS?