I'm running out of space ! I just finished 4-linking the rear of the Xj and i'm looking at doing away with my RE style radius links in favor of a 3-link. I hastily welded a 3/8 plate truss across the diff of the HP 44 going in. I don't really like the idea of a super-braced pass. side axle mount for a 3- link as i'm worried about the link separation with the center of the lowers mounted at the centerline of the axle tube. That leaves me with running a link on the drivers side. I'm not scared of cutting sheet metal as i already have to worry about covering up holes for a flipped 231doubler to a flipped 300 and two rear upper links :smokin:


Any pics of driver side 3-links? i've found several for tj's but not sooo much luck with the xj.

thanks in advance !
Adam

Not the best picture, but its a picture I guess.

http://i11.photobucket.com/albums/a154/mudonthetires10/My%20Truck/PicturesofMe013.jpg

I don't know how well the lower links being at the center of the axle will be. I would imagine if you are going with a 3-link you would want them towards the bottom, so the 3rd link effectively keeps the pinion angle intact.

Here's mine, about 40,000 miles on it and it works well.
The axle housing with all the bracketry welded on...
http://www.fototime.com/CF0FC25B0917639/standard.jpg
Driver's side...
http://www.fototime.com/08A228F8C4067A4/standard.jpg
After a lot of trail time...
http://www.fototime.com/CA8998B9DBF5868/standard.jpg

You guys really need to get over the "centerline of the axle" theory. It's bullshit. Having the link mounted at the axle centerline does NOT suddenly create infinite force on the other links, and in fact it's not much different than mounting it anywhere else.

FWIW, I run a single upper link on the driver's side in my XJ, with a passenger-drop diff, trussed all the way across. No biggie. Other folks have done them on the opposite sides too.

I dunno if it'll help your situation much, but here's how I snuck it in there...

http://www.phatserver.net/~chris/XJbuild/032407/DSC01617.JPG

http://www.phatserver.net/~chris/XJbuild/122406/DSC01133.JPG

http://www.phatserver.net/~chris/XJbuild/122406/DSC01131.JPG

My upper link is on the passenger side, as is Paul Sinclair's, and we've wheeled the dog shit out of them, both crawling and hauling ass. Mine has been that way for 6+ years. And, my lowers are in the middle of the tube (actually, slightly above center line).

Build it right, make it strong, make the seperation enough, and don't worry about what side it's on. I adjusted mine one time, increased the seperation at the axle to increase anti-dive, and it works well. If you want it on the drivers side, go for it, it can be done....but don't worry that you shouldn't put it on the pass side.

It can't be done :flipoff2:

Not the best picture, but its a picture I guess.

http://i11.photobucket.com/albums/a154/mudonthetires10/My%20Truck/PicturesofMe013.jpg

I don't know how well the lower links being at the center of the axle will be. I would imagine if you are going with a 3-link you would want them towards the bottom, so the 3rd link effectively keeps the pinion angle intact.

I hope that upper link is parallel to the bottom links, otherwise whats the frickin point?? :p

I hope that upper link is parallel to the bottom links, otherwise whats the frickin point?? :p

They shouldnt be parallel, its called proper geomtery

I hope that upper link is parallel to the bottom links, otherwise whats the frickin point?? :p

Huh? What makes you say that?

Why not just weld the upper to the top of the pumpkin? (why angle it to the side?)


flame suit on...

Without doing it properly you can not weld mild steel to cast iron and get a sound weld...It can be done but the average person does not have the equipment to do it.

http://i11.photobucket.com/albums/a154/mudonthetires10/My%20Truck/PicturesofMe015.jpg

;)

As far as I'm concerned, the upper link is pretty much only there to keep the pinion angle correct.
Also, welding the upper on the pumpkin brings up the cast issue, plus if you have a lot of uptravel there might be concerns with contact of parts above it. Had to consider the driveshaft being in that same general area as well.

Tech to the top BS to the bottom...

They shouldnt be parallel, its called proper geomtery

For a parralell 3 link setup w/panhard, the upper and lower links should be the same length and parralell to eachother horizontally for it to keep the pinion angle continous througout the range of motion. From the picture it looked like it may not have been :P

Looks much better in pic2 ! :smokin: Got a build thread on that S10?? Got a guy here locally who we are trying to get to do the same thing!

how do front 3 links due under hard breaking on the street?

Got a build thread on that S10?? Got a guy here locally who we are trying to get to do the same thing!

Don't have a build thread I don't think. I have some threads in different places that recaps everything with all the pictures I have, and then there is the photobucket location. PM me if you're wanting to see those and I'll dig up some links.

For a parralell 3 link setup w/panhard, the upper and lower links should be the same length and parralell to eachother horizontally for it to keep the pinion angle continous througout the range of motion. From the picture it looked like it may not have been :P

You're still making no sense.

Keeping the pinion angle constant should be the least of your concerns.

http://i11.photobucket.com/albums/a154/mudonthetires10/My%20Truck/PicturesofMe015.jpg

;)


Will the driveshaft work like that ?

Will the driveshaft work like that ?

Yeah, driveshaft angle is great. That picture is at full droop, so it normally sits quite a bit lower. The DS angle at ride height is awesome actually.

For a parralell 3 link setup w/panhard, the upper and lower links should be the same length and parralell to eachother horizontally for it to keep the pinion angle continous througout the range of motion. From the picture it looked like it may not have been :P

Looks much better in pic2 ! :smokin: Got a build thread on that S10?? Got a guy here locally who we are trying to get to do the same thing!



You're a dumbass and are contributing to the reason that dudes like adam90xj come here thinking that what they have done is correct...and then get all worried when it doesn't work right. If you don't know what the fawk you are talking about, go back to asking questions until you do know.







Adam: definitely move that upper link to the top of the diff at least. I've successfully welded to cast with either 6010 or 6011 (Can't remember). However, it wasn't pretty and I do suggest that you find someone with an arc welder or pay a welding shop to weld it with hi nickle content rod.

Actually, depending on the room, you want the upper link o be as close to center as possible. This helps to distribute braking forces evenly. Now don't get crazy if you can get to the actual center...just get it as close as possible TOWARDS the center without causing yourself heartache.

Here are four links to photo albums of my setup. I put a long arm 3 link on the drivers side of an xj with 4.0L/AW4/NP231/HP D44 front/LP D44 rear. It took some work, but it fit. I did rotate the 231 up just a touch, used a stock tranny mount, have a flat crossmemeber even with the bottom of the frame rails, modified the AW4 shifter a little to put the shift arm closer to the tranny, and redid the t-case shifter so the lever at the t-case points up and there is one link from that lever to the stock tunnel mounted cab shift lever. Some of the above posters have manual tranny's, different t-cases, or run shorter arms. All can be made to work with enough reworking of things. Jeff

http://share.shutterfly.com/action/welcome?sid=8IbtGzVo3bMoc

http://share.shutterfly.com/action/welcome?sid=8IbtGzVo3bMo-

http://share.shutterfly.com/action/welcome?sid=8IbtGzVo3bMpY

http://share.shutterfly.com/action/welcome?sid=8IbtGzVo3bMp6

I should mention that I used 4x6 box tubing cut in half to plate my frame rails, so the mounting of my crossmember may look a bit different. Here is an album of the frame rail work prior to doing the long arm 3 link front.

http://share.shutterfly.com/action/welcome?sid=8IbtGzVo3bMqU

I did a double triangulated 4link but my upper link frame mount idea could be used on a parellel 3, 4link.

http://www.wheelingarizona.com/forums/files/thumbs/t_000_0006_194.jpg

http://www.wheelingarizona.com/forums/files/thumbs/t_000_0003_186.jpg

http://www.wheelingarizona.com/forums/files/thumbs/t_000_0004_126.jpg

I did a double triangulated 4link but my upper link frame mount idea could be used on a parellel 3, 4link.

http://www.wheelingarizona.com/forums/files/thumbs/t_000_0006_194.jpg

http://www.wheelingarizona.com/forums/files/thumbs/t_000_0003_186.jpg

http://www.wheelingarizona.com/forums/files/thumbs/t_000_0004_126.jpg

That's interesting. I feel the vertical separation of the links at the frame is pretty minimal though. My setup puts the link up into the transmission tunnel. I'm not saying your setup doesn't work, but I just wanted to point out the minimal vertical separation of the links at the frame. Jeff

When I look at my truck, I fee like if I would have put the upper link on top of the pumpkin that I would have issues if the drivers side ever fully compresses.
I can't really see that upper link not having clearance problems. Maybe its just me?

You're a dumbass and are contributing to the reason that dudes like adam90xj come here thinking that what they have done is correct...and then get all worried when it doesn't work right. If you don't know what the fawk you are talking about, go back to asking questions until you do know.

Well then please enlighten the world with your wisdom as to the workings of a 3 link parallel system w/Panhard bar! :flipoff2:

Well then please enlighten the world with your wisdom as to the workings of a 3 link parallel system w/Panhard bar! :flipoff2:


When building a front link suspension caster angle takes priority over pinion angle. It should be designed so caster angle stays constant as the suspension cycles. This is done to have proper handling.

When building a rear link suspension pinion angle is what you are concerned with.

You have the right idea for the wrong end of the rig.

Front is setup for caster control, rear is setup for pinion control.

Thanks for the input. Jeff, nice work man. Like i said i know my way around the link calcs after setting up the rear 4-link. I was looking for some pics (thanks jeff) of the upper link actually fitting. Do you guys think that 1.5" .25 wall dom is strong enough? I have plenty of that or 2" .25 wall.....

Thanks !
Adam

Here are four links to photo albums of my setup. I put a long arm 3 link on the drivers side of an xj with 4.0L/AW4/NP231/HP D44 front/LP D44 rear. It took some work, but it fit. I did rotate the 231 up just a touch, used a stock tranny mount, have a flat crossmemeber even with the bottom of the frame rails, modified the AW4 shifter a little to put the shift arm closer to the tranny, and redid the t-case shifter so the lever at the t-case points up and there is one link from that lever to the stock tunnel mounted cab shift lever. Some of the above posters have manual tranny's, different t-cases, or run shorter arms. All can be made to work with enough reworking of things. Jeff

http://share.shutterfly.com/action/welcome?sid=8IbtGzVo3bMoc

http://share.shutterfly.com/action/welcome?sid=8IbtGzVo3bMo-

http://share.shutterfly.com/action/welcome?sid=8IbtGzVo3bMpY

http://share.shutterfly.com/action/welcome?sid=8IbtGzVo3bMp6

I should mention that I used 4x6 box tubing cut in half to plate my frame rails, so the mounting of my crossmember may look a bit different. Here is an album of the frame rail work prior to doing the long arm 3 link front.

http://share.shutterfly.com/action/welcome?sid=8IbtGzVo3bMqU

Nice work Jeff. I've learned to expect nothing less from you.:smokin:

So how are the Dodge rear springs working out? I was amazed about how soft the spring rate was.

When building a front link suspension caster angle takes priority over pinion angle. It should be designed so caster angle stays constant as the suspension cycles. This is done to have proper handling.

When building a rear link suspension pinion angle is what you are concerned with.

You have the right idea for the wrong end of the rig.

Front is setup for caster control, rear is setup for pinion control.

Oh come on dude...you're disappointing me now. :flipoff2:

Explain to me how you control caster independently from pinion angle on a solid front axle, and I'll be impressed. Last time I checked, if you keep the caster constant, the pinion stays in the same spot too. :evil:

Caster change on a crawler is pretty much a moot point. You're not going to notice it on a trail, and if you're driving on the road, you won't experience enough suspension travel for it to make a difference. This is why so many people run radius arm setups and get away with it. Leave that stuff to the IFS desert guys.

What you ARE going to be concerned with is the dive/anti-dive specs. This will determine how the weight transfer to the front is handled during braking, and also how the front reacts when climbing. In the 3-link I built on my rig, it dives a little bit during braking (which is normal and desirable to an extent), and also is very mild as far as unloading during climbing. It pretty much stays neutral (doesn't drop out very far). This is a function of the angle of the links, the instant center, tire contact patch, and the CoG of your rig. Rather than go into a big thing about how to design it, the easier thing is probably to post pics of ideas and then have people point and mark things that should be adjusted.

I'm fucking beat right now, so I'm going to end there, but I may pick this up in the morning.

Oh come on dude...you're disappointing me now. :flipoff2:

Explain to me how you control caster independently from pinion angle on a solid front axle, and I'll be impressed. Last time I checked, if you keep the caster constant, the pinion stays in the same spot too. :evil:

Caster change on a crawler is pretty much a moot point. You're not going to notice it on a trail, and if you're driving on the road, you won't experience enough suspension travel for it to make a difference. This is why so many people run radius arm setups and get away with it. Leave that stuff to the IFS desert guys.

What you ARE going to be concerned with is the dive/anti-dive specs. This will determine how the weight transfer to the front is handled during braking, and also how the front reacts when climbing. In the 3-link I built on my rig, it dives a little bit during braking (which is normal and desirable to an extent), and also is very mild as far as unloading during climbing. It pretty much stays neutral (doesn't drop out very far). This is a function of the angle of the links, the instant center, tire contact patch, and the CoG of your rig. Rather than go into a big thing about how to design it, the easier thing is probably to post pics of ideas and then have people point and mark things that should be adjusted.

I'm fucking beat right now, so I'm going to end there, but I may pick this up in the morning.

That reply wasn't for YOU it was for wannabe...

What was trying to sayto him is the castor angle is more important that pinion angle and should be kept constant in a front suspension setup for proper handling.
Some of us like to go fast too.:flipoff2:

In the rear the concern is keeping the proper pinion angle(pointed at the transfercaseif you run a cv).

My reply was just basics for wannabe

Roll center antidive, squat, cog and more are all big parts of the design. I just didn't want to overwhelm wannabe and was only correcting what he stated...

No shit, you can't control caster independently from pinion angle on a solid front axle. But you are concerned with what they are speced at as the suspension cycles.


I'd keep going but am off to work.

Thanks for the input. Jeff, nice work man. Like i said i know my way around the link calcs after setting up the rear 4-link. I was looking for some pics (thanks jeff) of the upper link actually fitting. Do you guys think that 1.5" .25 wall dom is strong enough? I have plenty of that or 2" .25 wall.....

Thanks !
Adam

I ran a 1.25 x .125 DOM upper link and had zero issues. You really don't need .250 wall for something that doesn't see rocks.

That reply wasn't for YOU it was for wannabe...

What was trying to sayto him is the castor angle is more important that pinion angle and should be kept constant in a front suspension setup for proper handling.
Some of us like to go fast too.:flipoff2:

In the rear the concern is keeping the proper pinion angle(pointed at the transfercaseif you run a cv).

My reply was just basics for wannabe

Roll center antidive, squat, cog and more are all big parts of the design. I just didn't want to overwhelm wannabe and was only correcting what he stated...

No shit, you can't control caster independently from pinion angle on a solid front axle. But you are concerned with what they are speced at as the suspension cycles.


I'd keep going but am off to work.

Blah blah blah... :flipoff2:

So for your mythical ideal rear suspension, if you wanted to keep the pinion pointing at the t-case yoke, I guess you'd be running rear radius arms?

(not directed at anyone)

The pinion angle changes in relationship to the TC, the caster angle changes in relationship to the ground. You can't contol both at the same time especially with a long travel suspension. A radius arm suspension is ideal for pinion control and a 4 link will control camber (ideally), you can't have it both ways without IFS.

At least that's how I picture it...:flipoff2:

Caster and pinion angle both change angle relative to the ground and to the transfer case, as the axle moves up & down; however, you're correct in stating you can't control their angles independently. You can modify the arm lengths and their relative mount positions in an attempt to point the diff at the transfer case over the range of axle movement, or you can minimise caster changes, but you can't "maximise" both at the same time. On the road, with a stiff suspension, axle movement is minimised, thus changes in caster and/or pinion angle is minimum. Off-road, maximum swings in axle position can easily result in drive shaft joint binding. So I'd approach design to insure minimal binding off-road, while maintaining minimum caster angle (~5*) over the narrow band of axle movement expected while driving smooth roads. I'd think high speed "dessert" driving would require you to maximise caster change control, while also paying attention to u-joint binding as the suspension bottoms out.

I was thinking along the same lines as vetteboy, that castor and pinion angle do not change independently from each other and therefore you want your castor to stay consistent throughout the range of motion. In order to do that the links need to be parrallel to eachother and the same length in order to insure that.

And in a radius arm design, the castor angle changes throughout the range of movement. Although the pinion is always going to be pointing to the same spot.

Nice work Jeff. I've learned to expect nothing less from you.:smokin:

So how are the Dodge rear springs working out? I was amazed about how soft the spring rate was.

The rear Dodge 1500 leaves on my XJ are still working great years later. :) I did actually add that second main leaf too! It sounds stiff, but it isn't. I do sometimes wish the front was a little stiffer though. The RE ZJ coils compress a little too easily with the non binding front suspension. Also, the idea of the parallel arms is so that the front axle is pushing and pulling on the links which minimizes torque movement one would get with a radius arm. It also holds the caster more or less constant through suspension movement, but in my opinion, that in itself isn't necessarily good or bad. When you are standing on your tail and ease into the throttle, you do NOT want the front end to try to droop and that's exactly what a radius arm type front suspension will try to do. I'm no expert in all this, but that's how I see the main difference between a 3 or 4 link and a radius arm front suspension. One DOES have to be very carful with pinion binding at full droop with a 3 or 4 link front suspension though. Jeff

clean up

When you are standing on your tail and ease into the throttle, you do NOT want the front end to try to droop and that's exactly what a radius arm type front suspension will try to do. I'm no expert in all this, but that's how I see the main difference between a 3 or 4 link and a radius arm front suspension. One DOES have to be very carful with pinion binding at full droop with a 3 or 4 link front suspension though. Jeff

So your saying that the torque, instead of transfering to the body of the jeep, will instead try and uncompress your suspension?

Basically since the upper is pointing down toward the center of the lower arm, that when the torque pushes that upper link into the lower link, and the lower link is hooked onto the axle and frame, that it's going to push the axle down (droop) since it would take more weight to push the body down (compression)? Does changing the location of the upper link mount closer to the body side change this effect?

Just trying to understand the logic here. Does acceleration cause the same torsional stress as braking on the setup?

hey vette boy,
i need a little advise for the new build of my cherokee......yeah i know my links and stuff are small you told me that last time....so now im putting a 9 inch in the rear with a hp 44 front this time im going to be using 1 or 1.25 hiems at the axle and a poly bushing at the frame for the front and hiems at both ends on the rear.....i plan on changing from a triangulated 4-link front to a 3-link with a panhard bar front....i just really dont know a whole lot about the 3-links ofther than you want to try and get the panhard bar the run in the same plane as the steering linkage....i am thinking of running the upper link on the passenger side.....how exactly will this work in conjuction with the panhard bar going from driver side to passenger side?.....

hey vette boy,
how exactly will this work in conjuction with the panhard bar going from driver side to passenger side?.....

vette is asleep but here my take

the track bar should angle toward the front side of the axle upper link mount

these are great (top of pic)

the offset ones let the track bar tower be in front of the axle centerline

http://www.pirate4x4.com/forum/showthread.php?t=666462&highlight=offset

http://www.ruffstuffspecialties.com/gallery/albums/userpics/10001/Panhard%20section%20pic.jpg


I cut my own offset into some 2x3 tube
i saw these and figured I could cut some off set into the upper arm axle end also
http://www.ruffstuffspecialties.com/catalog/images/adjustable%20link%20tower.jpg



http://www.supermotors.net/getfile/679200/fullsize/track-bar-view.jpg

vette is wishing he was still asleep

Fixed... :(

I solved this problem by using a passenger-drop axle. :D

Plenty of guys have done it though...besides the one that was just posted, check out xj_man_646's build, XJ_Ranger has the same type of setup. It's gonna be a little different for everyone so you pretty much have to get under there, lay it out, and see how it fits.