Pro and con of a wish bone Vs two straight links?
Rebuilding the rear and would like some input.

assuming you are talking about the way desertoy has his set up:


pros...less rear steer, seems to work better than you current setup :flipoff2:

cons. you don't have one


if i was redoing mine thats the way i would do it. i have not seen any faults,

Why not use a 3 link? If you tweak a control arm on a rock you still have a functional suspension without binding. That's what I'm doing with my rig... 3-link (http://briefcase.yahoo.com/bc/realsquash/vwp2?.tok=bcUC9BPBt4nXMgXG&.dir=/Yahoo!+Photo+Album/S10Buildup&.dnm=front3.jpg&.src=bc)

Not that I'm an expert or anything, just throwing out ideas.

Squash

Originally posted by camo


pros...less rear steer, seems to work better than you current setup :flipoff2:

cons. you don't have one




Camo you sure are getting a lot of mileage out of beating me over a couple of obstacles.:flipoff2:

Just you wait I'll be back, I'LL BE BACK. :mad: :mad2: :mad3: :D

I liked my three link but the time I broke the upper hiems joint i sure wished i had a 4 link. what a pita to fix with the diff pointing straight up and your driveshaft all tweaked.:mad3:

Originally posted by Pook
I liked my three link but the time I broke the upper hiems joint i sure wished i had a 4 link. what a pita to fix with the diff pointing straight up and your driveshaft all tweaked.:mad3:


been there done that !!!



Adam,:mad: :mad: :mad:

[QUOTE]Originally posted by Pook
[B but the time I broke the upper hiems joint <INSERT> NEEDED BIGGER HEIM what a pita to

Yeah it just seems like too much pressure on the middle heim on a 3 link. You can get just as good of performance from a triangulated 4 link with more points to take the stress. Not that I know from experience, just by looking at all the pretty pictures:D

Originally posted by Air Bag


Camo you sure are getting a lot of mileage out of beating me over a couple of obstacles.:flipoff2:

Just you wait I'll be back, I'LL BE BACK. :mad: :mad2: :mad3: :D

oh it's been a long time in coming. so i gotta take my shots while i can. :D

After ride'n with DToy this last time at the Hammerz, I was very impress'd with the rear suspension.... I however am leaning towards the traditional 13 link rear with a standard R bar front and F links.....:D

Originally posted by Tin Bender's Goat
After ride'n with DToy this last time at the Hammerz, I was very impress'd with the rear suspension.... I however am leaning towards the traditional 13 link rear with a standard R bar front and F links.....:D

13 links....???? Its gonna look like a jungle gym underneath there.

Originally posted by Adam Ant



been there done that !!!



Adam,:mad: :mad: :mad:

Well that's why I put 2 on top and 1 on the bottom. Less chance to smack one. I wouldn't think that a triangulated 4-link would be any better in this area.

For just torque on the axle, having 2 on top and 1 very near axle centerline is better than 2 near axle centerline and 1 on top as a 3-link is traditionally done.

Not harping, just learning and experimenting :beer:

Squash

Went from a standard 4link "M" to an upper wishbone and 2 side links. I like it much better. I saw all the problems guys were having using a heim so I build a urethane bushed swivel kinda thingy that works great. Venom uses a stander set of rubber bushing from the rear of a Ford radius arm for pivot, cushion and 'give'. It also works great. I wouldn't use a heim joint there unless you spent lots of money on a really good one. To much side load on the threads. Here's the one I made, the blue bushed part rotates 360 deg.
http://www.greatnorthern.net/~fearme/tech/side%20mounting.jpg

Originally posted by FearMe
Went from a standard 4link "M" to an upper wishbone and 2 side links. I like it much better. I saw all the problems guys were having using a heim so I build a urethane bushed swivel kinda thingy that works great. Venom uses a stander set of rubber bushing from the rear of a Ford radius arm for pivot, cushion and 'give'. It also works great. I wouldn't use a heim joint there unless you spent lots of money on a really good one. To much side load on the threads. Here's the one I made, the blue bushed part rotates 360 deg.
http://www.greatnorthern.net/~fearme/tech/side%20mounting.jpg


This is a good reason to run a 3-link, too. There is virtually no side load on the joints if it's designed properly.

Squash

Originally posted by Pig Penn


13 links....???? Its gonna look like a jungle gym underneath there.

Maybe I can re-design it with a 12 and a 1/2 link, with two snaps in a circle.....

Originally posted by Tin Bender's Goat


Maybe I can re-design it with a 12 and a 1/2 link, with two snaps in a circle.....

haha..........the 1/2 link would be key.

I suggest you locate the longest links in a suppository position.

In my past experience with 3-link and 4 link set ups the "Tri-Angulated 4 link" and "3 link wishbone" work great. The key thing to do is "OVERKILL" in the materials building it to eliminate any "weak" factors........IMHO......Good luck...

PS:I made my Tri-Angulated 4 link on my "late" 93 x-cab to the same specs that 10,000 pound "Grave Digger" uses.....no problems what so ever.....$$$ well spent...:D :beer:

Originally posted by Realsquash


Well that's why I put 2 on top and 1 on the bottom. Less chance to smack one. I wouldn't think that a triangulated 4-link would be any better in this area.

For just torque on the axle, having 2 on top and 1 very near axle centerline is better than 2 near axle centerline and 1 on top as a 3-link is traditionally done.

Not harping, just learning and experimenting :beer:

Squash

Realsquash I see a problem with your setup. Assuming that you are using a panhard that is connected to the frame on the driveside and then going to the passenger side on the axle. Lets think about this a minute. Lets say you are going down the highway and you have to suddenly stop. The Left front tire locks up and then tries to move backwards to the rear of the truck. This is because your link is several inches about the centerline of the axle. If you have the bottom link in the center of the axle housing you will probably be okay but it looks like your bottom link is on the right side. I would put the top links to the bottom and the bottom link to the top and you will be in a lot better shape. Now this is just my opinion. As for hitting the links if they was on the bottom I don't think you would hit them hardly at all. Talk to the bronco guys and see how many times the hit there raduis arms.

Well first of all, this truck will hardly see the road except between trails and test drives.

In my design the upper links will still take the brunt of the torque from stopping power, just like under power except the forces are higher with stopping. Just think of it as the pinion wanting to rasie up under braking, go down under forward power. The whole axle doesn't move backwards under braking.

The lower link being offset to one side won't make any difference unless one tire happens to lift off the ground, in which case I'm screwed anyways. And a tire that is locked up produces less torque than one on the threshold of skidding...

Also, the link(s) being on the centerline of the axle take very little torque. The link(s) mounted 8" above the axle centerline will take the rest of the torque, which is most of it. I'd rather have 2 on top and 1 on the bottom in this case.

Does this make sense? I've run through the math of it 134^3 times and it still makes sense in my head. Maybe I'll end up changing it, who knows? But the combination of tradeoffs in this setup make me the happiest, so only wheeling time will tell!

Squash

The whole axle will not move backwards but the left side will move backward. This is going to give you some funky brake steering. I would be very careful when tring it out. When you are tring to stop the bottom link is going to take most of the force with your setup. Good luck.

How can you say the bottom link is going to take all the force? That's just wrong. It's torque. It's just like grabbing a pen with both hands and trying to twist it. How can one side move rearward and the other not?

I could take my suspension and place another lower link that mirrors the lower that I currently have on the other end of the axle and the axle would move *exactly* the same way, except now there is natural binding.

Am I missing something? Please explain what you're thinking?

Squash

Originally posted by Realsquash
How can you say the bottom link is going to take all the force? That's just wrong. It's torque. It's just like grabbing a pen with both hands and trying to twist it. How can one side move rearward and the other not?

I could take my suspension and place another lower link that mirrors the lower that I currently have on the other end of the axle and the axle would move *exactly* the same way, except now there is natural binding.

Am I missing something? Please explain what you're thinking?

Squash

The axle housing is going to rotate around the top links under braking. I know that you have the bottom link to keep it from rotatiing but the driveside will still buckel under the load. I say try it, I might be wrong. Good luck.

I'd like to hash this out so I don't do something stupid, but I'm not getting an explaination I can comprehend. Do you mean that one side will have more torque than the other? For that to happen my axle housing would have to twist or break in half!

Explain a scenario where the driver's side buckles underneath the truck under braking... I can't do it, you want to enlighten me?

Squash

Realsquash
I have to agree with everyone else here. That design is not sound. Any advantage that one link on the bottom might give is going to be totally out weighed by the added stresses and quirky handing characteristics of that design.

By the way two links low out by the wheels is better than one link low in the middle anyway.

OK lets say the links are strong and will almost never break.
Does anyone think there is an advantage to one or the other? (other than strength)

your design is sound and bind free.
also copys the 4wheel truck placement of the 3 links.
i think these people believe an axle housing is made of spagetti

I'm still not seeing the argument against my design (in this regard). One side cannot simply buckle under unless some part fails, but that isn't your argument.

Weird handling? What are you basing this on? It's just torque, rotating force! :confused:

Squash

Originally posted by Realsquash
I'm still not seeing the argument against my design (in this regard). One side cannot simply buckle under unless some part fails, but that isn't your argument.

Weird handling? What are you basing this on? It's just torque, rotating force! :confused:

Squash

I am basing this on working on the Wristed Raduis arms for broncos. Yes it is just torque but how the load is distributed is where the problems. Your axle house does rotate as it flexes. So when you hit the brakes it will try to rotate the housing one direction and your suspension will jack or lower and that is when you will get your brake steering problem. I say try it out and see how it works but hold on because something could happen. Safari Gard had a setup like yours and it failed twice on them when they was testing it in Grand Junction. It appears that they have it worked out now but I would not trust it. Talk to Steven Watson I believe he was there when Safari Gard suspension failed.

lets see a pic of the wristed that had trouble.
does it have 3 solid links?
I am doubting it

Yeah as far as the geometry goes Your design if I understand it corectly is fine. there is a higher load on the lower link than the upper link, but when you are going forward the lower link is in tension. I think what Donovan was starting to say is that under breaking the lower link would be in compression and may buckle.
If you ran tires with a rolling radius of 19" 39.5's maybe. and the upper and lower links were 6 inches apart, and the vehicle weighed 5000 lbs assuming 1G breaking and 100% weight transfer to the front, then under breaking the lower link must withstand 20,833 lbf of compression, and each upper link must withstand a 7,916 lbf tensile load. If that lower link had a little bend in it it would buckle for sure. I am guesing your links are about 3' long (36") for a solid steel rod to resist buckling when it was perfectly straight under a 20833 lb compressive load it would need to be 1.16 inches in diameter. A 1.5 .250 wall tube would support this load with a safety factor greater than 2. If the entire 5000 lbs of the vehicle was supported in the middle of the 1.5 .120 wall tube the bending stress would be 17000 psi, so mild steel would not be likely to bend.

I know my guesses on sizes and weights are probably way off, but I just thought I would throw some numbers up. the math isn't guaranteed either.

Actually your numbers are pretty close! The distance between the upper and lower links is about 8.5". After weighing almost all componenents I'm getting a total target weight of 4200 lbs, but I've been figuring for 4500 lbs. I haven't figured the sprung weight yet. The upper links are about 48" long, lower is around 39" long. I will most likely be running 39.5" (advertised) diameter tires, possibly 42" or 44".

I'm glad to see numbers that jive with what I've been figuring... I haven't been able to run this by too many people with any experience in this area.

Squash

Originally posted by mj
lets see a pic of the wristed that had trouble.
does it have 3 solid links?
I am doubting it

I didn't say that the wristed arm failed it was a 3 Link setup that failed. Look here. http://www.safarigard.com/3Link.htm That is what failed. There has been only one wristed arm that has failed that I know of and the guy was going backwards up a ledge under full throttle and with I think they was 39" tires. The I beam just buckled inward and made the radius arm look like a U-shape.