Front upper control arms on 2005 LJ

[open_circuit]

Heard some discomforting noises on the trail run today, and discovered that the bump stop plunger was hitting the front springs under certain conditions. This can only happen if the front axle either moves (forward or backward) or rotates (pinion angle rotation). Jim noticed that my front upper control arm on the passenger side is buckling, and the driver side has twisted presumably due to the other arm buckling. So, I need a new front upper control arms in short order.

Installation looks pretty simple, though I'd appreciate advice on whether I've selected appropriate parts, and welcome any assistance with installation.

For control arms, it looks like these will get the job done -- https://www.quadratec.com/p/jks-manufacturing/j-flex-adjustable-front-upper-control-arms-84-06-jeep-wangler-tj-cherokee-xj
These appear to be much more stout than the stock upper control arms, which are some really cheesy ~1/8" steel in a U-shaped channel. These (https://www.quadratec.com/products/56015_005.htm) appear to the same construction as the currently installed (failed) upper control arms.

I imagine I also need to get some replacement bushings for the axle-side mount with the JKS part above? I found this (https://www.quadratec.com/products/56015_103.htm) on Quadratec, and assume it is compatible with the JKS control arms, though I'm not certain.

I lack an impact wrench, but I have a large breaker bar. I'm wondering how much pain I'm in for trying to remove the 15 year old bolts that hold these factory control arms in.

Thinking about how to replace the control arms, I understand the process to be:

1) Jack up the vehicle and put the frame on jack stands. Remove both front wheels.

2) Remove bolts at both ends of front upper control arm on one side, and replace. Jack up front or rear of front diff as necessary to adjust pinion if axle shifts when I remove the old control arm. Since both control arms that I have are bent, how should I set the new control arms to get the length correct?

3) Install new control arm and bolts. Repeat 1-3 for the other side

4) Lower vehicle and torque control arm bolts per spec, which appears to be 60 ft-lbs

5) Drink some beer.

What did I miss? Should I do something to secure the axle before trying to remove the control arm? I assume the axle will be in the wrong position when I jack up the vehicle owing to the broken upper control arms currently installed.

[open_circuit]

Here's the damage to the current control arms:

Passenger side - buckled / collapsed
https://i.imgur.com/bgd9gisl.jpg

Driver side - twisted and now bent towards the passenger side. Note the pinch on the right side and the curve in the arm.
https://i.imgur.com/nIf953Fl.jpg

[Brian]

I have lower adjustable control arms on the front and I've adjusted them without jacking or tire removal. Just do one at a time and the other side should hold the axle in place. Maybe remove the least bent one first and try to straighten it a little then match the length on the new ones, or just search around to get center to center length.

My question is how did this happen? I know they're flimsy (I have the stock upper ones too) but I can't think of a scenario that would cause this type of bending.

[open_circuit]

I don't really know how it happened. My best guess is that I damaged the passenger side one when I clipped a large rock I didn't see on the way out of Coney Flats / MSV earlier this year. There was a noticeable jolt when I contacted the rock, but I didn't see any damage at the time. Certainly since then, I've noticed some odd noises and I've been concerned about the front axle possibly not being centered, as I notice the wheel was no longer oriented correctly with the wheels facing forward. However, it is also possible this happened in Moab in October when I was stuck on the rock on Lockhart basin. While clearing the rock, and for the rest of the day, I noticed the sounds that I now know were the springs contacting the bump stop plunger.

Either way, I'm fairly concerned about how these could both be so badly damaged, and what else might be damaged as a result or concurrently. My front lower control arms are after-market fully boxed steel, so I'm guessing they were so strong compared to the uppers that the uppers simply failed when the axle was driven upwards during some event like the two above.

[Getaklu]

These shouldn't be hard to replace at all. Per the installation instructions for the pair you chose, the factory length is given making it that much easier, at least for a starting point.

[open_circuit]

Thanks Chris, I did see that. I wondered if stock length is appropriate with my lift. Going to try to measure the least damaged one in situ and see if they are close to stock length.

[open_circuit]

Without knowing how the uppers failed before, does it seem like a good idea to go with a beefier replacement like the jks? Wondering if whatever causes this happens again, if stronger control arms will just result in something worse breaking when the arms are not the weak point. Am I overthinking this?

[Java]

Why were the lower arms replaced? Has there been any welding done on the axle or frame nearby, maybe around a bracket like where the trackbar attaches? Those arms don't take a lot of stress compared to the lowers, I don't think you did that yourself with regular wheeling, but you may have exposed a previously weakend part(s). I'd guess your Jeep had an incident before you got it and they maybe should have replaced the uppers then. From the twisting on it I'd guess a front / side collision or a really hard hit offroad on an angle, or maybe it was allowed to hang from the upper arms while being manipulated to install the lift springs and they got twisted. All just guesses. I can't see a downside to beefier arms, although OEM replacements would probably be fine.

[open_circuit]

Lower arms are part of the lift kit I believe. Not sure why they were replaced if not with the lift.

[Jim]

Stock or aftermarket - my thoughts...

Stock: lower cost, one piece (vs. aftermarket adjustable that could have component failure), lower cost. If they were strong enough to not cause the MFGR costly warranty callbacks they should be reasonable to keep using.

Aftermarket: higher cost, multi-piece adjustable, appear stronger. If you wish to be able to adjust - this is a big bonus - but - you need to keep the jam nut tight. If it loosens and the vehicle is driven, the threads get hammered and will eventually fail (cue Dante? at one of the china wall runs). You have the ability adjust caster (a nice plus, especially if other work is non-stock).

Your concern of moving a weak link from an easily replaceable part to a different part is valid - but I view this part as too weak. Beefing up this component would not likely find you moving failure point to a more costly / difficult to repair item. I was in this debate with the front lock-out hubs - strong warn or weak brand - I'm back to warn as the weak brand hubs were just too weak.

I'd go aftermarket and keep the jam nut tight.

[open_circuit]

Dante's control arm failure (stripped threads) has been on my mind as I debate which part to buy. Delaying purchase while I wait for this debate to play out. I don't want to do the work twice, and want to buy the most appropriate part, not necessarily the cheapest part.

[Java]

IIRC you have the OME 2.5 kit, that does not come with control arms from what I see online. Do you have a vehicle history?

edit- I just spent a minute googling " Jeep TJ Upper Control Arm Bent" and it's not just you. I think I just learned something and I'm going to take a look at mine...

found this too https://axleaddict.com/trucks-vans/How-to-Set-Your-New-Adjustable-Jeep-Control-Arms-for-Each-Lift-Size

[open_circuit]

I ordered the JKS control arms. Curious to hear what you've found. I know the previous owner (director at my company), so I can get just about any question answered. I believe the vehicle was not wheeled or wrecked before I got it.

[FINOCJ]

Your concern of moving a weak link from an easily replaceable part to a different part is valid - but I view this part as too weak. Beefing up this component would not likely find you moving failure point to a more costly / difficult to repair item.

I am kind of with Jim on this, but I am not that familiar with TJs control arms - I helped a friend install and OME lift, and we did a short arm lift with no changes to the control arms and it has held up well so far. But I would also venture he hasn't wheeled it as hard as Trent has done....if you can get a beefier control arm, I would go that route...I can't think of any negative other than added weight (and I guess some work with getting the length adjustment right). In terms of strengthening one part and moving the failure point down the line, I can't think of any obvious failure points that would be a concern. There are also quite a few different solutions to ensure the nut stays tight, from various locktite options to a single use, deformed lock nut like what is used on pinons (they often have a dimple on them).

[open_circuit]

I am kind of with Jim on this, but I am not that familiar with TJs control arms - I helped a friend install and OME lift, and we did a short arm lift with no changes to the control arms and it has held up well so far. But I would also venture he hasn't wheeled it as hard as Trent has done....if you can get a beefier control arm, I would go that route...I can't think of any negative other than added weight (and I guess some work with getting the length adjustment right)

I suppose I was worried that next time the brackets might separate from the frame or axle instead of the arm breaking. I would hope that doesn't happen, but the brackets are also a little wimpy looking. Regardless, I've purchased the JKS control arms and will be installing them this upcoming weekend if everything arrives before Saturday.

[Jim]

Others can offer info on axle housing / frame control arm mounts breaking. I'm curious to hear the thoughts. In my view - failure of those items has not been a noted/routine/heard-of failure point of jeeps (for the use we give'm, the hold-my-beer-and-watch folks are a different crowd).

Additionally, the jam nut should be an easy-to-view item (oil changes or getting gas) where you could apply an inspection marking onto the nut to arm surfaces to see if it has loosened for quick-and-easy piece of mind. Here are a couple sites selling the item (low cost):

https://www.markingpendepot.com/dykem-cross-check.aspx

https://www.aircraftspruce.com/catalog/cspages/crosschecktorqueseal.php
(https://www.aircraftspruce.com/catalog/cspages/crosschecktorqueseal.php)
edit: I read the reviews on the above item and there's a mixed bag as to the package drying up after the first use. Some folks comment on using F-900 Torque Seal so I went searching for that product - it's the product I used on the fasteners on my ultralight. It seems that company went out of business (the F900 product shows available on Amazon). I'd still buy one of the items listed above with the realization that the tube of stuff might be one-time-use (the tube of stuff might dry up years before you loosen and need to re-mark the jam nuts).

https://crosschecknow.com/bath/

https://www.amazon.com/F-900-Orange-Torque-Seal-Tube/dp/B00JFKU8QW/

[open_circuit]

In my industry, we usually use some 2-part epoxy or RTV to stake fasteners. I imagine that would work well in this situation as well. It may not secure the jam nut, but it would definitely break if the nut moved.

[Jim]

It may not secure the jam nut

correct - inspection markings are only for inspection - not physical rotation control

[newracer]

Tearing the mounts from the frame or axle can/does happen but it's not too common.

Just get some penetrating thread locker for the jam nuts.

[Java]

The only other thing I can think of is that you do have a lift and sway bar disconnects, but your bumpstops are stock length.

[open_circuit]

The only other thing I can think of is that you do have a lift and sway bar disconnects, but your bumpstops are stock length.

So you think the front axle could articulate too much when the sway bar disconnects are off? I'm unsure if the bump stops are stock length or have been modified. Haven't looked into it yet.

[Java]

That's what I thought too. It would be an easy fix if it is...

[open_circuit]

It's worth looking into. It also may be unnecessary with the JKS upper control arms. These arms have a spherical joint on the frame side, which allows some twisting when flexing the suspension. The stock bars only have rubber bushings in this location, so they must travel in a vertical plane. Any twist on the stock uppers would be absorbed in the body of the component.

I'll have to research the bump stops and see if they need to be adjusted, or if the replacement uppers can eliminate that from the list of concerns.

[newracer]

Bump stops are to limit travel so your tires don't rub and to prevent any other suspension parts from hitting anything.

[Tom]

It's worth looking into. It also may be unnecessary with the JKS upper control arms. These arms have a spherical joint on the frame side, which allows some twisting when flexing the suspension. The stock bars only have rubber bushings in this location, so they must travel in a vertical plane. Any twist on the stock uppers would be absorbed in the body of the component.

I'll have to research the bump stops and see if they need to be adjusted, or if the replacement uppers can eliminate that from the list of concerns.
I replaced mine when I lifted my jk. Replaced is not quite correct. I left my stock ones in and added a hockey puck which I adhered with contact cement to point where the stock stop hits near the axle.

I can post a pic if interested.

[Java]

Clank! ... if that sound is coming from your suspension, that's not a good thing. If you just bottomed your springs and heard that metallic clank, it probably means you banged metal on metal and are at risk of bending or breaking some part of your suspension. And that means you probably need a reminder on the value of bump stops. Let's take a look at the function of a bump stop and some of the various applications for them.
The main purpose of a bump stop is to serve as some final suspension cushion to keep the metal parts from coming together or from traveling too far, which might in some way damage the suspension or chassis. In the case of a coil-sprung suspension, you'll want the bump stop to stop movement before a condition know as "coil bind," in which the coil spring is completely collapsed and can compress no further.

https://www.fourwheeler.com/how-to/0904or-bump-stop-tech/

[open_circuit]

Parts are all expected to arrive by Friday. Anyone want to join me on Saturday for some wrenching?

[Jim]

I'm available Saturday.

[FINOCJ]

I could be down...I have to go to the airport on Sat to pick someone up, but I am not sure what time that would be...
Are there any tools you would need?

[open_circuit]

Impact wrench would be helpful, as well as an extra jack (3 ton?). I only have a decent bottle jack, so if we need to try to jack up the axle to get the arms in place, a second would be handy (one in front/back of the differential to change pinion angle, perhaps). I can pull the emergency bottle jack out of the Jeep to do this if needed, but it is a pretty slow tool for the job.

Jim offered an impact wrench when we were wheeling this past weekend, but so I'm hoping he brings that. The hard parts of the job are probably breaking free the rusted bolts on the arms and pressing out / in the bushings. I planned to borrow or rent a ball joint press from a local auto shop to deal with the bushings, but if you have a ball joint press or a better tool for the job, that would be welcomed as well.

I have a couple of 2-ton jack stands and a couple of 3-ton jack stands, so I should be good there. Already have a decent set of mechanics tools and big breaker bar + torque wrench. I'm sure there's something else I haven't thought of, though. Trying to type out the list here, to help reconcile what I have against the original post of what we need to do to see if there are gaps.

[FINOCJ]

I planned to borrow or rent a ball joint press from a local auto shop to deal with the bushings

This is the one that came to my mind....but I don't have one. I do have a big pickle fork and hammer which can be useful for separating steering linkages from the knuckle if needed. I also have an impact gun and a number of other helpful air tools, but they are all air tools which means they need a decently large compressor to keep running for very long.

I also verified I don't have to be to the airport until 8:30pm, so I can definitely help out during the day. keep us posted

[Jim]

Tools available:
Torque wrenches
Air compressor - not large but usable enough
Air impact wrench & sockets
Wheel chocks
Short jackstands
Tall jackstands
Bottle jack
Floor jack
Punches
Heavy mallet
Pry bars (tire irons)
Cutoff saw and discs (what I used when needing to remove bushings / springs from the jeep - slip the cut-off blade inside the mounting perch and cut the bolt into pieces)
Kerosene turbo heater
110v AC power portable heater

If you think of anything else - post it up and I'll check.

[open_circuit]

Looks like a good list with very little overlap of what I already have. I imagine tall jackstands will be helpful, in particular, since we need to get up to the frame.

[Getaklu]

May want to start the penetrating oil regimen tonight if you are worried about the hardware. A ratchet strap or two may come in handy as well. Other plans Saturday or i would jump in. Shouldn't take too long at all (famous last words).

[open_circuit]

I have a can of PB Blaster in the garage. I plan to douse the bolts daily until Saturday.

[FINOCJ]

Tools available:
Torque wrenches
Air compressor - not large but usable enough
Air impact wrench & sockets
Wheel chocks
Short jackstands
Tall jackstands
Bottle jack
Floor jack
Punches
Heavy mallet
Pry bars (tire irons)
Cutoff saw and discs (what I used when needing to remove bushings / springs from the jeep - slip the cut-off blade inside the mounting perch and cut the bolt into pieces)
Kerosene turbo heater
110v AC power portable heater

If you think of anything else - post it up and I'll check.

So, will all that fit in the YJ, or the Honda (sorry - can't remember what your DD commuter car is)....

[Tom]

I can join on Sat. Have a cheap harbor freight impact gun, and the bar James was discussing.
I am not a mechanic but can lend moral support and drink beer with the best of em.

[FINOCJ]

Planning on sat...I'll post as we get closer if that changes....I can bring lots of tools, heater, etc....Maybe I'll try to cruise up in the WIllys

[open_circuit]

Bushings are in hand and the control arms are slated to be delivered later today. Still looking good for tomorrow. Going to scrounge a ball joint press or bushing press after work today.

[FINOCJ]

Planning on being there - as long as the Willys can make it there....

[Jim]

I'll pack the car tonight for an easy departure in the morning.

[Tom]

I will be there.

[open_circuit]

All parts and tools that I intended to get are in my hands.

I also grabbed some bratwurst to throw on the grill for lunch.

[open_circuit]

Thanks Jim, James, and Tom for coming out today and lending a hand. It took about an hour and a half longer than predicted due to a stubborn bushing on the differential housing. The upper control arms mount to a sheet metal bracket welded to the axle on the passenger side, and a solid cast-iron feature on top of the differential on the driver side. Due to the limited contact on the passenger side mount, it was relatively easy to press the bushing out with the ball joint press. However, on the driver side the bushing has much more surface area in contact with the mounting hole since the bracket is a couple inches of cast iron. We had to cut away the rubber interior of this bushing and then use a dremel with a grinding bit to cut a slot through the bushing's metal shell before we were able to successfully beat the bushing out in a crumpled heap.

We installed the lower control arms fairly easily after replacing the bushings. JKS provided new 10.9 bolts, washers, and locking nuts for the axle-side of each control arm. As we tried to torque the first (passenger-side) of these to the specified 60 ft-lbs, the new bolt snapped. I owe JKS an e-mail to ask about this. I am quite disappointed that their new hardware failed immediately and dramatically. We tried to torque the driver-side bolt, and it felt uncomfortably elastic, so we aborted. Ultimately, we secured the control arms with the old (original) bolts we removed from the failed control arms.

Failed control arms:
https://i.imgur.com/iRWbT7Wl.jpg

Failed bolt and suspect bolt:
https://i.imgur.com/2S7NRYCl.jpg

[Jim]

A good project done. It was nice work'n with all. Brats were delicious - thx!

Traffic on 25 was heavy. "mostly" running at road speed but it was thick the whole trip.

[Tom]

A much more enjoyable day than I would have had otherwise.

[FINOCJ]

Fun day...always fun wrenching on someone else's jeep.

[open_circuit]

JKS is sending me some replacement hardware. The person who responded says the torque spec should be 45 ft lbs, not 60, and they will update the instructions to clarify this. With how easily that bolt failed, I'm a bit skeptical still. Maybe I'll try to torque down the one remaining bolt to 45 and see if it feels wrong or fails before I both trying to install the new replacement hardware.

[FINOCJ]

I was thinking that bolt broke way too easily, so I started looking up torque specs for bolts. I generally consider grade 10.9 to be about equivalent to grade 8 in SAE terms and thought it should hole a lot more torque as it was somewhere around a 3/8 bolt I think. Anyway, i am not sure what the metric bolt size was, but guessing it was an M10 (about a 3/8), which for grade 10.9 should have a torque spec of 75Nm (about 55ft-lbs). So if it was an M10, we were pushing past the torque spec trying to get to 60ft-lbs, but it shouldn't break that close to the torque spec. Unless that bolt was smaller diameter than I remember. If it was more like an M8 bolt (5/16), then the grade 10.9 torque spec would be 40Nm (or about 30ft-lbs)...

[Jim]

So, would 60Nm be what the spec sheet was meaning when it was saying 60ft-lbs?

[open_circuit]

So, would 60Nm be what the spec sheet was meaning when it was saying 60ft-lbs?

Instructions are available here:

https://www.quadratec.com/sites/default/files/installation_instructions/jks-front-upper-adjustable-control-arms-JKS1652.pdf

Page 2 shows 60 ft-lbs for TJ, ZJ, and WJ. 55 ft-lbs for XJ and MJ.

[FINOCJ]

60Nm would be 45ft-lbs...so yes, seems like there is a good chance the torque spec units got mix up....But even so, it worries me than a 10.9 M10 would break before 60ft-lbs as max torque spec is still 55ft-lbs...

[Jim]

I believe ya Trent and I understand James' aspect too. I'm simply looking at this and thinking of NASA's Mars Climate Orbiter mission that spectacularly failed due to an SAE/Metric mixup.

https://www.wired.com/2010/11/1110mars-climate-observer-report/

A NASA review board found that the problem was in the software controlling the orbiter's thrusters. The software calculated the force the thrusters needed to exert in pounds of force. A separate piece of software took in the data assuming it was in the metric unit (https://www.wired.com/science/discoveries/news/2008/05/dayintech_0508): newtons.

My mind comes around to this quality control question: Should the installed fasteners be at the torque setting they were set at?

[open_circuit]

Yes, I think the flag bolts / nuts should probably also not be at 60 ft-lbs if they are the same grade and size as the hardware from JKS. However, even if I loosen and torque to 45 ft-lbs instead (for both the upper and lower bolts), would the bolt already be considered stressed and suspect? I don't have replacement hardware for the upper (frame) mounting location.

[Jim]

If over-torqued (by a decent amount), I'd replace.

If under-torqued, I'd set to proper.

---

You should be able to research to see what the factory spec fastener is and what the factory spec torque is. I'd go that route vs. using the questionable re-supplied aftermarket fasteners. You should be able to purchase (pickup at your local dealership parts counter) the fasteners.

[open_circuit]

Probably will be tricky to source a replacement for those flag bolts on the upper control arm frame mount.

[FINOCJ]

I believe ya Trent and I understand James' aspect too. I'm simply looking at this and thinking of NASA's Mars Climate Orbiter mission that spectacularly failed due to an SAE/Metric mixup.

I would figure the mistake came from JKS direction writer/translater....whomever wrote the directions got the units mixed up...


If over-torqued (by a decent amount), I'd replace.

If under-torqued, I'd set to proper.

Although Jim is 100% correct with replacing anything over torqued, and just tightening I'd be less worried about re-using the flag nuts as they are not locking nuts...technically the threads could have been damaged. The front fasteners locking nuts should only be used once even if properly torqued - if under torqued they can be re-used.

[Jim]

I don't think the flag nuts need to be used. While the "holding arm" of the flag nut makes it easy to get the nut onto the end of the bolt, the frame is open to the outside such that a standard locking nut can be easily put onto the bolt end.

A trick that can help get a standard (non-flag) nut onto the end of that bolt, is to place a piece of paper between the socket and nut and then push the nut into the socket. This will hold the nut nicely in the end of the socket for it to stay put while it's being started onto the bolt. The socket can easily enough be pulled out/off when needed. Sometimes this is too tight and only a sliver of paper - to interface one hex face of the nut-socket - is desired.

[open_circuit]

I was thinking that bolt broke way too easily, so I started looking up torque specs for bolts. I generally consider grade 10.9 to be about equivalent to grade 8 in SAE terms and thought it should hole a lot more torque as it was somewhere around a 3/8 bolt I think. Anyway, i am not sure what the metric bolt size was, but guessing it was an M10 (about a 3/8), which for grade 10.9 should have a torque spec of 75Nm (about 55ft-lbs). So if it was an M10, we were pushing past the torque spec trying to get to 60ft-lbs, but it shouldn't break that close to the torque spec. Unless that bolt was smaller diameter than I remember. If it was more like an M8 bolt (5/16), then the grade 10.9 torque spec would be 40Nm (or about 30ft-lbs)...

I have the replacement hardware. The bolts are marked as 10MM- 1.50 x 80MM, class 10.9 clear zinc. The nut is called out as 10MM - 1.50 Prevailing torque nut zinc