Mopar Lift - Control Arm Torque Question

[Yardstick]

I installed the Mopar lift over the last few days. Between deciphering errors in the instructions and other interruptions it took longer than it could have. And my JL Rubicon Ecodiesel ended up about 4 inches higher in the front and 2.75 inches higher in the rear. I’m happy with the increased ride height up front. It finally has a reasonable amount of space between the bump stop and pad, rather than the inch or so that it had before.

My question is about the control arm torque specs in the instructions. Some of the torques seem high, but maybe reasonable. Others have to be wrong. For example, they show 190 ft-lbs on the front lower control arm M16 bolts. That’s probably reasonable, but awfully high. Most of the rear control arm bolts have torque specs of 185 ft-lbs and the two upper bolts at the frame are 200 ft-lbs! I got most of them up there, thinking they were also M16 bolts. And then the right rear control arm to axle bolt had a problem. It got up to about 155 ft-lbs and then continued turning as the peak torque on my torque wrench kept going down. I think that bolt is about to fail. I’m hoping it’s just the bolt anyway. It turns out that the rear control arm hardware is all M14! There was no reason to measure them ahead of time but I wanted to verify once I started looking for replacements. The instructions have a discrepancy in the rear control arm hardware too, saying some are M16, while others are M14 bolts with M16 nuts. Maybe this is partly my fault for trusting the torque values given in instructions that otherwise had a bunch of errors, but it’s really disappointing that this is something that Jeep/Mopar puts out. So if you did this lift, where did you get your torque values from? What are the right torque values? And because I don’t trust any of the bolts now, where can I get new rear control arm hardware?

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[BDinTX]

I copied these numbers from the AEV lift install instructions and added a few notes. Have loosened and retightened them several times over the last few years and never broke a bolt*
*When I used the right torque number, IE 190 ft-lb on a front UPPER control arm will not work

You might try a local parts dept and let them know you’d like a full set (or whatever you need). That upper control arm bolt was about $3.50 if I remember correctly…

 

[Mast562]

Just finished installing mine and i noticed that some of the spec values on the diagram differ from the torque spec list. Also bolt sizing is different.

 

[KHR Racing]

I’m not sure if this is going to help you or not…… but I generally go to”” almost stripping tight””.

 

[GATORB8]

Whoah, are you reading a Newton-Meter column? Other than front LCAs, those are way high.

This is the standard Mopar chart:

 

[BDinTX]

Whoah, are you reading a Newton-Meter column? Other than front LCAs, those are way high.

This is the standard Mopar chart:

I like your chart better!

 

[Terrymo]

I installed the Mopar lift over the last few days. Between deciphering errors in the instructions and other interruptions it took longer than it could have. And my JL Rubicon Ecodiesel ended up about 4 inches higher in the front and 2.75 inches higher in the rear. I’m happy with the increased ride height up front. It finally has a reasonable amount of space between the bump stop and pad, rather than the inch or so that it had before.

My question is about the control arm torque specs in the instructions. Some of the torques seem high, but maybe reasonable. Others have to be wrong. For example, they show 190 ft-lbs on the front lower control arm M16 bolts. That’s probably reasonable, but awfully high. Most of the rear control arm bolts have torque specs of 185 ft-lbs and the two upper bolts at the frame are 200 ft-lbs! I got most of them up there, thinking they were also M16 bolts. And then the right rear control arm to axle bolt had a problem. It got up to about 155 ft-lbs and then continued turning as the peak torque on my torque wrench kept going down. I think that bolt is about to fail. I’m hoping it’s just the bolt anyway. It turns out that the rear control arm hardware is all M14! There was no reason to measure them ahead of time but I wanted to verify once I started looking for replacements. The instructions have a discrepancy in the rear control arm hardware too, saying some are M16, while others are M14 bolts with M16 nuts. Maybe this is partly my fault for trusting the torque values given in instructions that otherwise had a bunch of errors, but it’s really disappointing that this is something that Jeep/Mopar puts out. So if you did this lift, where did you get your torque values from? What are the right torque values? And because I don’t trust any of the bolts now, where can I get new rear control arm hardware?

Please post a pic of your instructions showing these torque specs. As has already been said, something is either wrong or being misunderstood

 

[Yardstick]

This is the torque value page in the instructions for the Mopar 2" lift with Bilstein reservoir shocks.

 

[BDinTX]

Somebody else had a similar problem, take a look here:

https://www.jlwranglerforums.com/forum/threads/torque-specs-and-a-broken-m16-bolt.133987/

 

[GATORB8]

This is the torque value page in the instructions for the Mopar 2" lift with Bilstein reservoir shocks.

Wow, that's crazy.

Unfortunately, in the FSM, almost all the values are to yield (torque plus degrees). I don't have the fastener P/Ns in alldata, unfortunately.

Looking at the two versions of the mopar instructions, the revision has M16 part numbers and the original has M14 part numbers.

Rear:

Here's the front LCAs for comparison:

 

[GATORB8]

And now that I've reread your original post, seems like you knew all this already, and I need to go back to reading class.

I've got several fasteners upsized to Grade 8 SAE over the years, which may be easier to source from the aftermarket if your dealership can't get you the replacement pieces.

Grimm and Metalcloak offer full kits, Grimm 10.9 metric and MC Grade 8 SAE.

If you just want to get a control arm set, see if a company called Fastenall is nearby, we use them for fasteners in construction. McMaster Carr is also a great online source and should be able to get you almost anything the next morning.

 

[Yardstick]

It’s nice to see some numbers that should be a lot easier to achieve and not take the bolts way beyond yield. And I may get to use the angle feature on my digital torque wrench! I ordered all of the fasteners (bolts and nuts) that I over-torqued from an online Jeep parts place. I hope the brackets and bushings are okay.

I have toyed with the idea of swapping the bolts out for proper shear type hardware with clear shanks across the full width of the assembly. That and nylock nuts would be nice. Nylocks don’t damage the bolt the way deformed locknuts do and according to some aircraft testing information I’ve seen, they hold better too. The only nuts that might need to be the deformed type would be the front upper control arm to frame ones near the engine/exhaust. That would really all be overkill though since we aren’t relying on the bolt to be a pivot point. It just needs to hold the joint together.

I bought a Metalcloak bolt kit for a JK that I had where one control arm bolt was missing (what’s with me and control arm bolts??). The flag nuts looked really serious, but the whole kit was coarse thread bolts, rather than fine thread. Coarse thread bolts have a smaller minor diameter so they are a weaker fastener to begin with. Between that and the different thread pitch I calculated that they wouldn’t have the same tension as factory bolts at the same torque settings - if they could stand up to the factory torque settings. I’ll take a look at Grimm for curiosity. McMaster or an aircraft hardware supplier might be tempting but the flag nuts could be a challenge.

 

[Terrymo]

This is the torque value page in the instructions for the Mopar 2" lift with Bilstein reservoir shocks.

Wow that’s a dramatic difference on some of the specs

 

[Terrymo]

Yes sorry I also failed reading comprehension and as I reread your post see that my comments were irrelevant. Glad you’re getting it sorted out

 

[Yardstick]

No worries.

I have continued looking at a bunch of these parts and some parts lists show an M16 bolt for front and rear lower control arms. I measured mine, so I know they are M14. That means they have some discrepancies in their parts catalog too. I thought it might be possible that the Gladiator could be using larger rear control arm bolts but it looks like those are M14 too.

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