WJ Lower Control Arms in an XJ

WJ Lower Control Arms
Extra Clearance for Wider Tires

by Brandon Shehan
Posted: January 10, 2002
Last Revision:

The Problem:
Lower Contral Arm rub with wider tires is a near inevitability with XJ's.   I ended up with control arm rub running LT235 BFG AT k/o's.   Only at full lock, mind you, but nonetheless, it was a horrifying sound, like a baseball card in spokes, only several octaves lower.   There is a low buck fix comprised of putting a washer behind the steering stop bolts, but this increases your turning radius as the wheels can no longer turn those last few degrees. For rock crawling types or people who use the 'bounce it off a tree' technique to make it through tight spots, this may be acceptable. However, in the areas where most MADXJ'ers wheel, a tight turning radius is a good thing.   Nobody wants to have a supertanker turning radius.

The Solution:

There is an elegant OEM solution to this, however: The use of WJ (1999 and up Grand Cherokee) lower control arms. The WJ LCA's are the same length and have an S-bend specifically for tire clearance.   WJ Arms are sometimes available second-hand from people lifing their WJ's. Check the various boards, especially Jeeps Unlimited (http://www.jeepsunlimited.com ). The average price seems to be under 100 dollars per pair.   New ones from the dealer are roughly 80 dollars apiece.
The arms are not a DIRECT bolt-in, however.   The WJ's control arm pockets are wider than those of the XJ and consequently, so are the bushings.   The good news is that the main body of the arms will fit in the XJ's pockets.   All that needs to be done is to grind or machine down the bushings to XJ width.   A friend did the DIY style with angle grinder. He clamped the arm in a vise and ran the grinder with part of the wheel in a container of water to cool it. This prevented melting the rubber bushing.   I was not so bold and chose to have a machinist friend do it on a Bridgeport mill during lunch in exchange for some token money and an excess quart of POR-15. Either way, just measure the XJ's arms and evenly grind or cut the WJ's bushings (center sleeve and rubber) to the same width.

Tools and Procedures:

Installation is simply replacement of one set of arms with another. Nothing fancy here, just remember to do one side at a time.   Tools required are minimal: a jack, jackstands, a socket set, and a torque wrench that goes to at least 150 ft/lbs. If your arms have been on for a while or you live in salted-road parts fo the country, soaking the bolts and nuts daily with PB Blaster or some other penetrant (no, not WD-40) for about a week beforehand will make things MUCH easier. Air tools would make this job a bit faster, but the average joe can do it in his driveway. A helper would be ideal, but I managed to do it myself using a ratchet strap in place of the helper.   It's about a three beer job: one for each arm, and one before clean-up.

Safety Notice:

Always use jackstands to support the vehicle when working underneath it! The cheap Chinese-made hydraulic jacks used by many are not the highest quality and will bleed down. Even if you have a million dollar made-in-Switzerland Snap-On jack, you still need to use jackstands.   3500 lbs of truck suddenly landing on your chest can make breathing difficult. Gloves and eye protection are a must, as well. Bits of metal and dried mud are not good in the eyes. The gloves will prevent some skinned knuckles and cut fingers.

Tips and Hints:

Just remember to install the arms (which are interchangeable) with the round bushing towards the axle and the oval bushing towards the uniframe. The arms should curve INWARDS.   If you install them outwards, you'll have MASSIVE tire rub problems. Torque the bolts to spec (133 ft/lbs) when the vehicle is down with weight in it's suspension.   Use Locktite Blue when reinstalling the bolts for that 'extra secure' feeling.   Do this without a pair of toddlers wanting to "help" by hiding sockets and squirting Locktite all over the bumper.

Illustrated Summary
Due to the low resolution of some of the photos, there is no "click to enlarge" function.

Photo: Andreas Ritterbusch
These are the XJ (top) and WJ (bottom)Control Arms. Note the S-bend to the WJ arms. Also note the width of the WJ's bushings relative to the XJ bushings. The WJ bushings have not yet been machined.

Photo: Andreas Ritterbusch
Another view of the arms from the side. Note the shiny spot on the control arms caused by tire rub. The WJ arms have two different shapes of bushing. The round and the oval/football shape. The football bushings go towards the unibody.

Photo: Brandon Shehan
XJ LCA about to be removed. See that shiny spot where the tires rub?
Since the the sway bar should be disconnected, this would be a GREAT time to put in those Quick-Disconnect sway bar links.

Photo: Brandon Shehan
WJ arm installed on passenger side. While it's hard to tell from the photo, the arms bow INWARD as intended.

Photo: Brandon Shehan
Aligning the axle. Note the use of the ratchet strap to pull the axle forward with the jack to move it upwards. The driver's side proved to be far tougher than the passenger side for some reason. I bolted the axle end in first, then the body end.   I tried it both ways and somehow, this way worked when the other wouldn't.
The strap is affixed to the tow-hook on one end, and the swaybar attachment point on the axle. Both were very solid anchors.
In the end, it probably would've been easier if I had rented a spring compressor. Those OME 930HD springs can give quite the fight.
When you have them in place, put the wheels back on, set it down and torque the bolts to 133 ft/lbs. Don't forget to reconnect the swaybar.

Summary:
This is a good low-buck, high-bang upgrade for people running shorter (sub 4.5") lifts.   The S-bends provide lots of extra tire clearance without affecting turning radius. The rubber OEM bushings also promote a nice ride in comparison to some aftermarket polyurethane bushings or spherical rod ends (aka "Heim Joints").
It's not terribly appropriate for people "up there high" unless control arm drop brackets are used. If you're running big, you probably already have aftermarket control arms.
Special Thanks to Dennis Sinks for his help with the machining and to Andreas Ritterbusch for steering me to the idea (pun intended).

ŠCopyright 2002 Brandon Shehan
All Rights reserved.

[MADXJ]

The Problem: Lower Contral Arm rub with wider tires is a near inevitability with XJ's. I ended up with control arm rub running LT235 BFG AT k/o's. Only at full lock, mind you, but nonetheless, it was a horrifying sound, like a baseball card in spokes, only several octaves lower. There is a low buck fix comprised of putting a washer behind the steering stop bolts, but this increases your turning radius as the wheels can no longer turn those last few degrees. For rock crawling types or people who use the 'bounce it off a tree' technique to make it through tight spots, this may be acceptable. However, in the areas where most MADXJ'ers wheel, a tight turning radius is a good thing. Nobody wants to have a supertanker turning radius. The Solution: There is an elegant OEM solution to this, however: The use of WJ (1999 and up Grand Cherokee) lower control arms. The WJ LCA's are the same length and have an S-bend specifically for tire clearance. WJ Arms are sometimes available second-hand from people lifing their WJ's. Check the various boards, especially Jeeps Unlimited (http://www.jeepsunlimited.com ). The average price seems to be under 100 dollars per pair. New ones from the dealer are roughly 80 dollars apiece. The arms are not a DIRECT bolt-in, however. The WJ's control arm pockets are wider than those of the XJ and consequently, so are the bushings. The good news is that the main body of the arms will fit in the XJ's pockets. All that needs to be done is to grind or machine down the bushings to XJ width. A friend did the DIY style with angle grinder. He clamped the arm in a vise and ran the grinder with part of the wheel in a container of water to cool it. This prevented melting the rubber bushing. I was not so bold and chose to have a machinist friend do it on a Bridgeport mill during lunch in exchange for some token money and an excess quart of POR-15. Either way, just measure the XJ's arms and evenly grind or cut the WJ's bushings (center sleeve and rubber) to the same width. Tools and Procedures: Installation is simply replacement of one set of arms with another. Nothing fancy here, just remember to do one side at a time. Tools required are minimal: a jack, jackstands, a socket set, and a torque wrench that goes to at least 150 ft/lbs. If your arms have been on for a while or you live in salted-road parts fo the country, soaking the bolts and nuts daily with PB Blaster or some other penetrant (no, not WD-40) for about a week beforehand will make things MUCH easier. Air tools would make this job a bit faster, but the average joe can do it in his driveway. A helper would be ideal, but I managed to do it myself using a ratchet strap in place of the helper. It's about a three beer job: one for each arm, and one before clean-up. Safety Notice: Always use jackstands to support the vehicle when working underneath it! The cheap Chinese-made hydraulic jacks used by many are not the highest quality and will bleed down. Even if you have a million dollar made-in-Switzerland Snap-On jack, you still need to use jackstands. 3500 lbs of truck suddenly landing on your chest can make breathing difficult. Gloves and eye protection are a must, as well. Bits of metal and dried mud are not good in the eyes. The gloves will prevent some skinned knuckles and cut fingers. Tips and Hints: Just remember to install the arms (which are interchangeable) with the round bushing towards the axle and the oval bushing towards the uniframe. The arms should curve INWARDS. If you install them outwards, you'll have MASSIVE tire rub problems. Torque the bolts to spec (133 ft/lbs) when the vehicle is down with weight in it's suspension. Use Locktite Blue when reinstalling the bolts for that 'extra secure' feeling. Do this without a pair of toddlers wanting to "help" by hiding sockets and squirting Locktite all over the bumper.
Illustrated Summary Due to the low resolution of some of the photos, there is no "click to enlarge" function.
Photo: Andreas Ritterbusch	These are the XJ (top) and WJ (bottom)Control Arms. Note the S-bend to the WJ arms. Also note the width of the WJ's bushings relative to the XJ bushings. The WJ bushings have not yet been machined.
Photo: Andreas Ritterbusch	Another view of the arms from the side. Note the shiny spot on the control arms caused by tire rub. The WJ arms have two different shapes of bushing. The round and the oval/football shape. The football bushings go towards the unibody.
Photo: Brandon Shehan	XJ LCA about to be removed. See that shiny spot where the tires rub? Since the the sway bar should be disconnected, this would be a GREAT time to put in those Quick-Disconnect sway bar links.
Photo: Brandon Shehan	WJ arm installed on passenger side. While it's hard to tell from the photo, the arms bow INWARD as intended.
Photo: Brandon Shehan	Aligning the axle. Note the use of the ratchet strap to pull the axle forward with the jack to move it upwards. The driver's side proved to be far tougher than the passenger side for some reason. I bolted the axle end in first, then the body end. I tried it both ways and somehow, this way worked when the other wouldn't. The strap is affixed to the tow-hook on one end, and the swaybar attachment point on the axle. Both were very solid anchors. In the end, it probably would've been easier if I had rented a spring compressor. Those OME 930HD springs can give quite the fight. When you have them in place, put the wheels back on, set it down and torque the bolts to 133 ft/lbs. Don't forget to reconnect the swaybar.
Summary: This is a good low-buck, high-bang upgrade for people running shorter (sub 4.5") lifts. The S-bends provide lots of extra tire clearance without affecting turning radius. The rubber OEM bushings also promote a nice ride in comparison to some aftermarket polyurethane bushings or spherical rod ends (aka "Heim Joints"). It's not terribly appropriate for people "up there high" unless control arm drop brackets are used. If you're running big, you probably already have aftermarket control arms. Special Thanks to Dennis Sinks for his help with the machining and to Andreas Ritterbusch for steering me to the idea (pun intended).
ŠCopyright 2002 Brandon Shehan All Rights reserved.