Front drag link question

[Andrew XJ]

what modifications are required to use a drag links do I only need a modified crossmember and the drag links and upper control arms?

[4.3LXJ]

I don't think I understand your question

[bigjim350]

Are you talking about long arms using radius arms?

Sent from my SPH-L300 using Tapatalk 2

[Andrew XJ]

yeah I was referring to long arms using radius arms.

[NW99XJ]

Long arms always require the addition of/installation of/or fabrication of, a cross-member more times than not.
You "could" fab up just the control arm mounts off of the unibody, but I would highly advise that a set of frame stiffeners go in before hand regardless.
This will give you a better base to build off of no matter which way you decide to go.

Now that we have that out of the way, we need to cover the differences between the different types of long arm set ups.

A true 4 link long arm set up has 4 individual "long arms" that mount to 4 different spots on the both the vehicle and the axle itself.
A good example of this would be the Full Traction 6" Long Arm Suspension System pictured below.
This kit does not use a dedicated cross-member, but instead uses new hangers to mount the control arms to the unibody/frame.
http://www.quadratec.com/Assets/Images/78543/78543-lg.jpg

Another example would be the BDS 4.5" Long Arm Suspension kit.
This one uses a true dedicated cross-member to tie everything into.
http://ok4wd.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/b/d/bds_xj_45_la_2.jpg


A radius arm set up utilizes just one mounting point for the rear of the control arm at the body/frame side,
and 4 points on the axle. Essentially its one arm each side, with a "Y" at the end of it to attach at the axle.
An example of this would be the long arm upgrade kit from Ironman 4x4:
http://www.ironman4x4fab.com/images/STD-LAK-F.jpg

Here you can see a similar radius arm set up installed:
http://memimage.cardomain.com/ride_images/1/3206/2401/8013700094_large.jpg

The exception to all this is the 3-link set up like the one from IRO (Iron Rock Offroad)
They use just one, long, singular arm on one side, and a radius arm on the other...creating 3 mounting points on the axle itself.
These kind of systems generally can produce more flex, but often times are considered weaker,
due to the fact the are only using one point of one arm to control castor (pinion angle.)
http://img69.imageshack.us/img69/7809/oldcontrolarmcutoff1.jpg

This system too, uses a dedicated crossmember to attache the arms at a farther point back on the vehicle.
http://www.ironrockoffroad.com/Merchant2/120908%2011.jpg

In the end, everyone is going to have their own opinions as to which type of system is best.
Personally I would do some research, as much as possible really, and read as many reviews as you can.
Also, try to talk to some people who have ran these set ups as well.
...even better find a person who has ran them all and really pick their brains for advice, as to what their preferences and experiences are with the different systems.

I hope this helps, and clears some things up for you.
Good luck with your build.

[Andrew XJ]

Long arms always require the addition of/installation of/or fabrication of, a cross-member more times than not.
You "could" fab up just the control arm mounts off of the unibody, but I would highly advise that a set of frame stiffeners go in before hand regardless.
This will give you a better base to build off of no matter which way you decide to go.

Now that we have that out of the way, we need to cover the differences between the different types of long arm set ups.

A true 4 link long arm set up has 4 individual "long arms" that mount to 4 different spots on the both the vehicle and the axle itself.
A good example of this would be the Full Traction 6" Long Arm Suspension System pictured below.
This kit does not use a dedicated cross-member, but instead uses new hangers to mount the control arms to the unibody/frame.
http://www.quadratec.com/Assets/Images/78543/78543-lg.jpg

Another example would be the BDS 4.5" Long Arm Suspension kit.
This one uses a true dedicated cross-member to tie everything into.
http://ok4wd.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/b/d/bds_xj_45_la_2.jpg


A radius arm set up utilizes just one mounting point for the rear of the control arm at the body/frame side,
and 4 points on the axle. Essentially its one arm each side, with a "Y" at the end of it to attach at the axle.
An example of this would be the long arm upgrade kit from Ironman 4x4:
http://www.ironman4x4fab.com/images/STD-LAK-F.jpg

Here you can see a similar radius arm set up installed:
http://memimage.cardomain.com/ride_images/1/3206/2401/8013700094_large.jpg

The exception to all this is the 3-link set up like the one from IRO (Iron Rock Offroad)
They use just one, long, singular arm on one side, and a radius arm on the other...creating 3 mounting points on the axle itself.
These kind of systems generally can produce more flex, but often times are considered weaker,
due to the fact the are only using one point of one arm to control castor (pinion angle.)
http://img69.imageshack.us/img69/7809/oldcontrolarmcutoff1.jpg

This system too, uses a dedicated crossmember to attache the arms at a farther point back on the vehicle.
http://www.ironrockoffroad.com/Merchant2/120908%2011.jpg

In the end, everyone is going to have their own opinions as to which type of system is best.
Personally I would do some research, as much as possible really, and read as many reviews as you can.
Also, try to talk to some people who have ran these set ups as well.
...even better find a person who has ran them all and really pick their brains for advice, as to what their preferences and experiences are with the different systems.

I hope this helps, and clears some things up for you.
Good luck with your build.

I wanted to go with long arms that use radius arms but I can't exactly afford the crossmember but it's a very needed upgrade. the previous owner of my Jeep crashed and it ended up damaging where my control arms mount to the unibody nobody can get the pinion angle right and it is causing unusual where on the outside of the tire. I was going to get the long arm kit and weld a custom mount to my cross member.

also I apologize for the title I should not be posting after a night of drinking

[4.3LXJ]

Just one tire or both?

[Andrew XJ]

Both

[4.3LXJ]

Personally, to me that sounds like a toe in problem.

[Andrew XJ]

it's wearing the sidewall tread because the axle is pointed too far forward

[4.3LXJ]

Did an alignment man tell you this?

[Andrew XJ]

no I can see it whenever I turn and drive forward at the same time tires are angle too far forward so instead of the tires just turning they also turn down a little bit

[4.3LXJ]

They are supposed to do that. That is why the lower part of the C is longer than the upper part. So when you turn the wheel in either direction, the lower part of the wheel the tire starts to be at a different camber angle. This is by design. I know it sounds dumb. But the C and knuckle configuration is standard for all D30 axles. Then the factory applies differing amounts of castor for each wheel base. This serves two purposes. If the castor is tilted towards the back, the wheels will want to self center and the vehicle drive straight. Also there is a thing called the Ackerman Angle. It is difference in angles the front wheels have to be at to track properly in a full turn. The inside needs to be at a sharper angle that the outside. Changing the castor angle changes the Ackerman angle. For an XJ wheel base it is 5°