Rebuilding JBA Adjust a Struts - part numbers

[Johnny O]

Bert has a mystery noise. Is a metallic rotational sound that only appears over 12-15mph. Noise is consistent- does not increase in frequency or pitch with increase in speed. Only noticed it when driving through a Jersey-barrier construction zone with window down. According to coworker, has sounded like that for months (thanks for lettin' me know, bruh). No other symptoms.

All wheel bearings check out ok (they should as they are moogs with barely 12k on them), both diffs check out, front prop checks out. Brakes check out fine.

Suspect driveshaft(?) U-joints?(?).

Stumped.

Suggestions?

 

[DadOSix]

Bert has a mystery noise. Is a metallic rotational sound that only appears over 12-15mph. Noise is consistent- does not increase in frequency or pitch with increase in speed. Only noticed it when driving through a Jersey-barrier construction zone with window down. According to coworker, has sounded like that for months (thanks for lettin' me know, bruh). No other symptoms.

All wheel bearings check out ok (they should as they are moogs with barely 12k on them), both diffs check out, front prop checks out. Brakes check out fine.

Suspect driveshaft(?) U-joints?(?).

Stumped.

Suggestions?

Transfer case chain?

 

[Johnny O]

Transfer case chain?

just noticed I put this in the wrong thread. No hijack intended.

Didn't think of that, Ill look into it, thanks!

 

[lfhoward]

Removing the JBA Adjust-A Struts from the KK was a big job. Everything else in the front suspension had to be removed first, with the exception of the upper and lower control arms.

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Prior to surgery, but bump stops removed.

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Drivers side. Some parts loosely put back together after strut removal.

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Passengers side:

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The clevis bolt on the passengers side was seized in the control arm bushing. After trying a bfh, a c clamp, breaker bar, etc., I used a cutting wheel to remove the bolt, which didn't turn out to be the best idea. I recommend a sawzall and lots of blades for the next person, because you can be more precise. You can see the cuts I made in the lower control arm by mistake. I will be getting another lower control arm from a junkyard, because this one is no longer safe or usable.

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At the end of the day though, I had the shock towers removed. The CV axles had to come out with them, because the clevis on the JBA adjust a strut is not removable like it is on the stock unit.

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Also, some things under the hood had to be removed to access the shock tower bolts. On the passengers side, the airbox came out. This was pretty easy.

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On the drivers side, the battery, TIPM, and battery tray had to come out. This was a difficult job. I only partially broke one electrical connector, but hopefully not a big deal since the part I broke was external. The electrical connectors are in ziplock bags to protect them from dirt and sweat.

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I took a picture of how the connectors were arranged, so that I can put them back later (front is to the left). I am also storing the TIPM indoors instead of in the garage, so that humidity and corrosion are not going to happen while the Jeep sits fot the next few weeks.

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It's important to keep everything organized that you remove, and put nuts back on bolts so you know where they go later.

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The shocks will be shipped to the rebuilder this afternoon. Meanwhile, I will find a new LCA for the passengers side, a new shock/clevis bolt and nut, and new bump stops. I also need new lower ball joints, as mine were trashed even before this job. Moogs are on the menu.

Nobody said this was cheap. But all the labor above was free.

 

[lfhoward]

In my last post I noted that I accidentally cut into the lower control arm on the passengers side while trying to remove a seized bolt with an angle grinder. I found a replacement LCA on ebay from another 08 KK that had only 69,000 miles on it for only $60 shipped. Today that arrived. I am a little underwhelmed.

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The part number is correct, but this thing is a little crusty. It's just surface rust I think, so I will wire-wheel it off and then paint with Rustoleum before installing. I like that they left the sway bar link installed for the last 12 (or however many) years. That will protect the threads for the sway bar bolt inside the LCA from rust. The ball joint will be going away and be replaced with a greasable MOOG.

I am a bit worried about the LCA bushings though. Let me know what you think. Is this dry rot only going to be only external, or are these things trashed throughout? I was hoping to not have to replace the bushings, as I do not have a hydraulic press. I suppose I could take it to a local shop to have them press out the old and press in new.

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Would you run that?

If I do get all new bushings, I should probably do the other side as well. Mine on the other side are original too (2007 vintage), but maybe in not as bad shape as these. Also, my JBA UCA's have 12 year old bushings too, and those could be pressed out and upgraded. JBA sells a bushing replacement kit for that:

JBA TC-69000 UCA Bushing Kit

Includes 8 synthetic elastomer a-arm bushings, to service a pair of arms.

jbaoffroad.com

It is a PITA to remove the front UCA's though, particularly the one on the drivers side. Is this mission creep? What would you do?

Cheers,
Lauren

 

[lfhoward]

I went ahead and bought new lower control arm bushings for both sides, including the connections with the frame and with the strut fork/clevis. I threw new sway bar bushings into the cart while I was at it.

I also ordered a new set of JBA upper control arm bushings as well.

Better to put safety first.

 

[KJowner]

That looks shot to me, mine are 20 years old and due for replacement too.

 

[lfhoward]

Note to self: KK Spring Rates

Front:
Stock: 310 lbs
OME:
925 Light Load: 350 lbs
926 Medium Load: 375 lbs
927 Heavy Load / CRD Medium: 400 lbs
790 CRD Heavy Load: 500 lbs
Replacement coilover springs should be somewhere in the 375-400 range of the 926/927's.

Rear
Stock: 210 lbs
OME 731: 280 lbs
Replacement 4" lift springs? Guessing 280-300.

 

[lfhoward]

More info on my JBA 4” rear springs:

I went out and measured.
14.75 coil diameter mm (0.58 in)
5 or 6 coils? (Depending on whether counting spacing or metal)
95 mm id (3.75 in)
About 12 in tall with the Jeep on them
14 in new height calculated from an old picture (355.6 mm) [spring sitting next to JBA upper control arm of a known measurement]

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Using this spring calculator…
https://eibach.com/spring-rate-calculator
… the spring rate could be 450-600# per inch. That’s like double the OME rate in the previous post, so the estimate may not be right (too high). I would check out some other spring rate calculators online and compare.

Edit: if my coil diameter is actually 0.5 in instead of 0.58 in, the spring rate comes down to 267-345# per inch. Using 0.5 would account for rust and paint thickness. The result is also more in line with OME’s spring rates.

 

[lfhoward]

Info on using Land Rover Discovery springs as a JBA 4” replacement:

KK 4" Rear Lift Springs (kind-of)

Hey guys, I figured it would be of use to someone to know that I have found a decent alternative for 4" rear springs since nobody advertises them anymore First off, gotta give OME credit. I had no idea they had an applications catalog with all their spring specs in it :D Here's a link to it...

www.jeepkj.com

 

[wheeee32]

Anyone know the valving specs for the shocks when they're new. I have an order placed but the manufacturer needs that info so they can fulfill my order. These are the shocks: https://www.vividracing.com/bilstein-7100-classic-coilover-shock-absorber-p-151564679.html
Any help would be greatly appeciated.

 

[lfhoward]

Anyone know the valving specs for the shocks when they're new. I have an order placed but the manufacturer needs that info so they can fulfill my order. These are the shocks: https://www.vividracing.com/bilstein-7100-classic-coilover-shock-absorber-p-151564679.html
Any help would be greatly appeciated.

Check your messages.

 

[lfhoward]

I realized I never posted pics on this thread of my front suspension rebuild, so here you go.

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LCA’s refurbished by me with Moog bushings & ball joints. (I bought a used shop press!)

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New UCA’s by JBA with brand new bushings and ball joints.

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Back together.

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I am very happy with how it turned out.

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Dialed in at 21.5” from center of the wheel to the bottom of the fender (3.5” lift in front). I could go a little higher but the electronic stability control is happier at this height than at 4” when taking slow bumpy 90° corners.

 

[wheeee32]

The setup looks great! Love it.

 

[derekj]

I realized I never posted pics on this thread of my front suspension rebuild, so here you go.

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LCA’s refurbished by me with Moog bushings & ball joints. (I bought a used shop press!)

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New UCA’s by JBA with brand new bushings and ball joints.

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Back together.

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I am very happy with how it turned out.

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Dialed in at 21.5” from center of the wheel to the bottom of the fender (3.5” lift in front). I could go a little higher but the electronic stability control is happier at this height than at 4” when taking slow bumpy 90° corners.

Does the bump stop just miss the grease fitting on the ball joint?

 

[lfhoward]

Does the bump stop just miss the grease fitting on the ball joint?

I believe so. The bottom is curved and I think it goes around the outside of the grease fitting. However, I rarely if ever hit the front bump stops as long as the front sway bar is attached. I don’t know if it would hit more often with other springs but my JBA adjust a struts plus the sway bar are stiff enough to prevent it.

 

[lfhoward]

Part of my lift rebuild that had me stumped for a while was how to replace the JBA 4” extended rear sway bar links that have been on Jeep since 2014. They were custom made by JBA back in the day.

A good solution looks like the Teraflex 3-4” lift rear sway bar links for JK’s. They are nearly the same length as the JBA links, which have long since lost their JBA red paint.

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Here is the info about the Teraflex extended links:

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Part number 1754500.
JK 3”-4” Rear Swivel Stud Swaybar Link Kit (Pair)

I’ll let you know how the install goes. I also got Moog rear sway bar bushings as well to replace the 15-year-old bushings on my Jeep.

 

[lfhoward]

Rear shocks for my 4” lift are Bilstein B8-5125’s, part number 33-185552. These match what was originally in my JBA lift kit.

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Close up of the part number:

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And the sleeves that go inside the shock bushings came with the shock too. Their part number is in the photo in case anyone needs to order them separately.

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I have started soaking the shock and sway bar bolts in Aerokroil to begin to loosen them up. I will install the shocks and sway bar links & bushings in a week or two if the weather cooperates.

 

[lfhoward]

In case anyone is interested, here is a how-to on how to refurbish your Bilstein M 7100 shocks, by Ian at Wheel Every Weekend. It doesn’t look like too bad of a job, although some specialized tools are required.

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