Flipping radius arms

[baldilocks]

I had that on my rig, done by a previous owner. He put 7" springs on and made a mount to move the axle forward to center the front wheel in the opening. Long story short, he didnt do it right. I bought it for a decent deal, because the guy i bought it from didnt want to put the money into it to do it right. It had death wobble that wouldn't go away. I ended up getting a new (to me) housing that still had the oem mounts and delta arms. It was cheaper than having a shop re-do everything. Georg @ Valley Hybrids did an excellent job doing the swap. Drives sooooo much nicer now. Rock solid at 75mph on 37's with beadocks. I never saw the upside. There was a little more under axle clearance, and a lot of tie rod clearance. Thats about it. Maybe if it had been done right, I would have left it.

Good points here. People cry about the arms decreasing ground clearance. I can say that I have never been stuck on a radius arm and they surely offer some protection to the tie rod. The arms are very transparent in my experience with regards to ground clearance and hang ups. They seem to slide right over everything they contact. Yes, the delta arms do wonders for handling at road speeds.

 

[cody c]

I had that on my rig, done by a previous owner. He put 7" springs on and made a mount to move the axle forward to center the front wheel in the opening. Long story short, he didnt do it right. I bought it for a decent deal, because the guy i bought it from didnt want to put the money into it to do it right. It had death wobble that wouldn't go away. I ended up getting a new (to me) housing that still had the oem mounts and delta arms. It was cheaper than having a shop re-do everything. Georg @ Valley Hybrids did an excellent job doing the swap. Drives sooooo much nicer now. Rock solid at 75mph on 37's with beadocks. I never saw the upside. There was a little more under axle clearance, and a lot of tie rod clearance. Thats about it. Maybe if it had been done right, I would have left it.

Interesting, very hard to argue with someone who has the first hand experience. Its really too bad you didn't figure out the source of the death wobble, it could have been caster, or bad TRE's or loose steer arms etc, would have been good to have identified the issue. 7" spring lift gets into the territory where there can be many things wrong.

 

[Grandlooser]

Look like the PO also said something about moving the panhard. Thats a big no no if done wrong for sure.

 

[orangefarmer]

Good points here. People cry about the arms decreasing ground clearance. I can say that I have never been stuck on a radius arm and they surely offer some protection to the tie rod. The arms are very transparent in my experience with regards to ground clearance and hang ups. They seem to slide right over everything they contact. Yes, the delta arms do wonders for handling at road speeds.

It was kinda amazing to see flat surfaces on the bottom of the axle. Sure, there's a chance that you might hit a radius arm under the axle, but its pretty close to the tire. I would think that if it were a problem there would be WAY more posts of people hitting or even breaking their radius arms. I haven't seen it, but I don't spend too much time on the forums.

 

[orangefarmer]

Interesting, very hard to argue with someone who has the first hand experience. Its really too bad you didn't figure out the source of the death wobble, it could have been caster, or bad TRE's or loose steer arms etc, would have been good to have identified the issue. 7" spring lift gets into the territory where there can be many things wrong.

Caster was the issue. The guy I bought it from put on (I would like to think marlin, but probably trail gear) heavy duty drag link and tie rod with new stabilizer. I checked the steer arms, when I got it, and they were taken off and put back on when I had the gears put in and axles (both) rebuilt. The po made custom panhards front and back. I replaced them with a delta bracket and ome bar in the back and an ironman in the front. Most of that happened when i took the 7" tjm springs off (they were too soft, and it doesn't have swaybars), and replaced them with slee 4 inchers(med front, heavy rear). I needed to re-center the axles. And i needed something heavier to support the new bumpers. I worked on it for three years, and finally came to the conclusion that the radius arms needed to be put back. I don't have the fab skills to do it myself, and to replace the bushings and have a shop rebuild the mounts would have been a lot. I bartered Georg for the housing, and had him do the swap. I guess I could have, but I don't have time at the moment. I've have had this thing for three years and have put 300 miles on it trying to get it back in shape from people that neglected it.

 

[orangefarmer]

Look like the PO also said something about moving the panhard. Thats a big no no if done wrong for sure.

I couldn't tell if the front panhard mount had been dick'd with, but it didn't seem to be. but the panhard and drag link were not on the same angle. I don't know if they're off some from the factory or not. there were so many things that had been dick'd with, that it was easier to start over.

 

[lumbee1]

I worked with an alignment shop to achieve 3* of perfect caster. With all the work involved with cutting off the front of the mounts, a flipped radius arm would have been better assuming there's clearance.

 

[orangefarmer]

I worked with an alignment shop to achieve 3* of perfect caster. With all the work involved with cutting off the front of the mounts, a flipped radius arm would have been better assuming there's clearance.

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There is so much more work that goes into the flip. I like your solution. I didn't see the advantage.

 

[baldilocks]

It was kinda amazing to see flat surfaces on the bottom of the axle. Sure, there's a chance that you might hit a radius arm under the axle, but its pretty close to the tire. I would think that if it were a problem there would be WAY more posts of people hitting or even breaking their radius arms. I haven't seen it, but I don't spend too much time on the forums.

My radius arms are beat to heck. What I was saying is that, although they do contact obstacles below, they don’t seem to present a sticking point.

 

[cody c]

I can see why people just 3 link these things, simple, easy to adjust caster with upper link, flexes better. The idea of bushings versus ball joints makes sense though, I think they absorb a lot of energy and they last a pretty long time, there has been a few threads on here where people have uni-ball or Johnny joints or whatever that come apart in under 10 or 30k miles or something. Would be nice to use a set of rear lower control arms as a donor for the lowers for a front three link. Sleeve them, add threaded rod or something to adjust them or allow them to rotate more and just bolt them to bolt holes on the frame bracket and axle, then add an upper

 

[orangefarmer]

I can see why people just 3 link these things, simple, easy to adjust caster with upper link, flexes better. The idea of bushings versus ball joints makes sense though, I think they absorb a lot of energy and they last a pretty long time, there has been a few threads on here where people have uni-ball or Johnny joints or whatever that come apart in under 10 or 30k miles or something. Would be nice to use a set of rear lower control arms as a donor for the lowers for a front three link. Sleeve them, add threaded rod or something to adjust them or allow them to rotate more and just bolt them to bolt holes on the frame bracket and axle, then add an upper

I think the best would be bushed at one end, and a joint on the other. those things can rattle your teeth out, there is no give. And I think that most people severely underestimate how much maintenance the joints take. they nee to be constantly taken apart, cleaned, and greased. Though you do get more articulation out of them.

 

[60 toy ota]

You guys watch that Russian dude who replaced all his bushings with bearings?

 

[Jarred]

It's a great idea, Toyota should have done this originally...luv the clearance it gives!

It would be a great feature if Toyota makes this as the original setup.

 

[cody c]

Here’s some pics of a Tacoma down the road with flipped 80 series arms

If your gonna comment on the bracket on the axle limiting flex, I see it too.

Otherwise it looks good

 

[Grandlooser]

By the looks of the paint scrapes Id say the tie rod hots the bracket as well.

 

[SNLC]

I am thinking about doing it on my 80 Ute project. I heard about it 15+yrs ago now being done in Australia, it is an old school mod for them. Now there is kits, I am looking at this one,

Landcruiser 80/105/79 Series Flipped Arm Kit - Castor Correction

Upgrade your 80/105/79 Series Landcruiser with our DIY Flipped Arm Kit for castor correction, increased clearance, and a smoother drive. Easy weld-on installation.

www.kinselaskustoms.com.au

Includes radius arms which appears to need no mods to the panhard. .65:1 aussie bucks to ours right now so that makes it cheap to me. Easy to make my own radius arm brackets on the axle side but I really don't want to start messing with the panhard mount, which I have seen raised when doing the flip mod. I am not interested in taking the panhard out of whack angle wise compared to the drag link. This will cause bump steer. I got a Diamond housing as well. More than anything I am curious about the mod and always try to do things like this on my Cruisers before a customers.

Cheers

 

[leonard_nemoy]

Looks like a cool mod and a good bang for the buck. If you do this I will be very interested in seeing how it turns out.

 

[mudgudgeon]

I am thinking about doing it on my 80 Ute project. I heard about it 15+yrs ago now being done in Australia, it is an old school mod for them. Now there is kits, I am looking at this one,

Landcruiser 80/105/79 Series Flipped Arm Kit - Castor Correction

Upgrade your 80/105/79 Series Landcruiser with our DIY Flipped Arm Kit for castor correction, increased clearance, and a smoother drive. Easy weld-on installation.

www.kinselaskustoms.com.au

Includes radius arms which appears to need no mods to the panhard. .65:1 aussie bucks to ours right now so that makes it cheap to me. Easy to make my own radius arm brackets on the axle side but I really don't want to start messing with the panhard mount, which I have seen raised when doing the flip mod. I am not interested in taking the panhard out of whack angle wise compared to the drag link. This will cause bump steer. I got a Diamond housing as well. More than anything I am curious about the mod and always try to do things like this on my Cruisers before a customers.

Cheers

Old school for sure. This was done a lot in Australia before aftermarket arms were available.
I contemplated doing it on my 4"lifted hdj80.

This was discussed lots on outerlimits4x4 back in the day. I think clearance under the housing is the only real advantage.
It pushes the axle forward very slightly (12mm from memory).

There's no real change in articulation because you're still constrained by the same bush spacing, same bush orientation, locked into rigid brackets with bushes spaced at 8".
The reason Superior's superflex arms work so well is because the bushes at the diff go from being spaced horizontally, to vertically so the bushes act as a hinge as the axle and radius arms twist on articulation .
Looks like the product you linked is emulating Superior's design. (Although other OEM's have similar configuration in radius arm bush placement)

I remember the guy from Superior Engineering (cant think of his name ATM) being part of the chat and talking about bump steer, squat/anti squat etc and saying there's no real change in any of this, as the relationship between radius arm pivot on the frame, and centre of axle housing doesn't change.

@orangefarmer Issues sound like a mix of install issues, and ongoing changes without full understanding of the issues.

The concept works. Like anything, it needs to be done properly for sure.

 

[SNLC]

Old school for sure. This was done a lot in Australia before aftermarket arms were available.
I contemplated doing it on my 4"lifted hdj80.

This was discussed lots on outerlimits4x4 back in the day. I think clearance under the housing is the only real advantage.
It pushes the axle forward very slightly (12mm from memory).

There's no real change in articulation because you're still constrained by the same bush spacing, same bush orientation, locked into rigid brackets with bushes spaced at 8".
The reason Superior's superflex arms work so well is because the bushes at the diff go from being spaced horizontally, to vertically so the bushes act as a hinge as the axle and radius arms twist on articulation .
Looks like the product you linked is emulating Superior's design. (Although other OEM's have similar configuration in radius arm bush placement)

I remember the guy from Superior Engineering (cant think of his name ATM) being part of the chat and talking about bump steer, squat/anti squat etc and saying there's no real change in any of this, as the relationship between radius arm pivot on the frame, and centre of axle housing doesn't change.

@orangefarmer Issues sound like a mix of install issues, and ongoing changes without full understanding of the issues.

The concept works. Like anything, it needs to be done properly for sure.

It also gives flatter radius arms. With a lot of lift the radius arms are on an angle vs flat. That will transfer some of the loads (from a large bump for example) to the frame mounts vs absorbed by the suspension. It also allows you to set caster via fabrication vs the other bolt in options. I would think the axle still swings in the same arc under articulation regardless of which side the radius arms are mounted to. Flatter arms = better though regardless. It also eliminates the tie rod to radius arm problem no matter what caster you give it. So there are more benefits than just ground clearance which I drag mine nearly every trip out.

I am not saying it is some great mod which will transform a Cruiser. It is a fairly cheap and fairly easy mod though that does have some benefits.

The Cruiser I may use it in I don’t want to do a 3-link right now. I still want to play with my suspension a bit and am curious about the flip since I have never done it. I also like to try things on my Cruisers if possible before doing on a customers Cruiser.

To me the kit above seems like a screaming deal, $900usd for radius arms, brackets, knuckle gussets and a truss. Sure the brackets and truss could be made for $100-200 but that takes time as well. Delta has the cheapest radius arms at $900ish a set? Most Aussie radius arms shipped to us will run around $1500.

Cheers

 

[mudgudgeon]

It also gives flatter radius arms. With a lot of lift the radius arms are on an angle vs flat. That will transfer some of the loads (from a large bump for example) to the frame mounts vs absorbed by the suspension. It also allows you to set caster via fabrication vs the other bolt in options. I would think the axle still swings in the same arc under articulation regardless of which side the radius arms are mounted to. Flatter arms = better though regardless. It also eliminates the tie rod to radius arm problem no matter what caster you give it. So there are more benefits than just ground clearance which I drag mine nearly every trip out.

I am not saying it is some great mod which will transform a Cruiser. It is a fairly cheap and fairly easy mod though that does have some benefits.

The Cruiser I may use it in I don’t want to do a 3-link right now. I still want to play with my suspension a bit and am curious about the flip since I have never done it. I also like to try things on my Cruisers if possible before doing on a customers Cruiser.

To me the kit above seems like a screaming deal, $900usd for radius arms, brackets, knuckle gussets and a truss. Sure the brackets and truss could be made for $100-200 but that takes time as well. Delta has the cheapest radius arms at $900ish a set? Most Aussie radius arms shipped to us will run around $1500.

Cheers

I agree, that package is a good deal and will have more benefits than flipping stock arms.

The comments about and being flatter is better are, from memory, a misconception.
Greg I think is the engineer from Superior. He gave a good explanation about the dynamics and geometry that I won't be able to fully remember or explain.
The critical things in relation to bump steer and bump absorption through the arm to the frame are not impacted by flipping standard arms ( or only minimally impacted).

The altered bush placing of the left side arm in the kit you linked is the key to improved flex.
Other OEM's used similar bush placement in radius arm suspension for both arms.

I've often thought I'd like to do flipped arms, with 6" longer radius arms, but also triangulate them inwards where they mount to the frame, and raise mounts above the belly of the frame.
Combine that with 45⁰ bush placement at the diff housing, you'd open up a lot of flex, and keep road manners inherent in radius arm suspension ( or most of the manners).
Combine that with longer rear links, also triangulated slightly and raised above frame belly, and you open the door to a low, flexible sleeper of a cruiser.

There's a **** load of work in all that though.