Driving to work today, almost in the parking lot, I heard a loud boom/thump pulling away from a stop light, and I had a bunch of driveline vibration. The cast iron piece that attaches the rear ball joint to the differential broke. I have a 4" JBA lift with their y-link extension. The two upper bolts (14mm 10.9 grade) on the differential also broke. I'm thinking that the boom was either the final bolt breaking, or the cast iron piece breaking. Anyone else have this happen? The y-link is also bent, and that is one beefy hunk of steel.

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JBA 4" lift, IRO Tri-link w/ wwdiesel bracket, JBA sliders, 235/85-16 Goodyear Wrangler Duratracs, Mercedes Benz forged ultralight wheels, Weeks stage 1 and 2, Weeks lift pump and harness, Weeks battery tray and AGM battery, GDE tune, Suncoast TC, updated front pump, HDS 001 T-stat, ARP studs, Front and rear Detroit/Eaton Truetrac LSD.

First we will get the small talk out of the way.
How long has it been on and do you use lock tite when reinstalling everything?
I have had something similar but here is what I think happened to mine and possibly yours
Mine had been on and off a lot of times, ( had went through I think 8 or 9 tri-links total , maybe more have to look)
I was then trying out the bolt on JBA replacement and had it on and off a few times as well.
I had been having some fun around town with a couple of JKs that I would run into every now and again.
I had launched mine really hard 6 or 7 times and then felt a vibration after the last one, no where to pull off and by the time I did had one bolt partially holding it together
In hindsight I think the bolts started backing enough to give me the vibes , then out enough the bracket could move some
Then bam broke the two bolts off ( two upper)
The diff bracket didn't break on mine , just the bolts

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

No locktite. 4200 miles. The ball joint seems to be good, and it is the original. I think I'll upgrade to the bolt on 4-link, and I'll be sure to use locktite this time.

quote="tommudd"]

First we will get the small talk out of the way.
How long has it been on and do you use lock tite when reinstalling everything?
I have had something similar but here is what I think happened to mine and possibly yours
Mine had been on and off a lot of times, ( had went through I think 8 or 9 tri-links total , maybe more have to look)
I was then trying out the bolt on JBA replacement and had it on and off a few times as well.
I had been having some fun around town with a couple of JKs that I would run into every now and again.
I had launched mine really hard 6 or 7 times and then felt a vibration after the last one, no where to pull off and by the time I did had one bolt partially holding it together
In hindsight I think the bolts started backing enough to give me the vibes , then out enough the bracket could move some
Then bam broke the two bolts off ( two upper)
The diff bracket didn't break on mine , just the bolts[/quote]

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JBA 4" lift, IRO Tri-link w/ wwdiesel bracket, JBA sliders, 235/85-16 Goodyear Wrangler Duratracs, Mercedes Benz forged ultralight wheels, Weeks stage 1 and 2, Weeks lift pump and harness, Weeks battery tray and AGM battery, GDE tune, Suncoast TC, updated front pump, HDS 001 T-stat, ARP studs, Front and rear Detroit/Eaton Truetrac LSD.

sounds like the bolts got loose and when they shifted the final time it popped the heads off the bolts, 10.9's will sometimes sheer instead of bend depending on where the stress is, glad it didnt happen to ya farther from a parking spot thats for sure!

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03 Renegade (Black)
177k miles 3.7L gas - 45RFE
Command Trac / 4.10s
Lift: ft. 790+ rr. JBA4+
The last of the TrailReady Front&Rear Bumpers and TR Rock Rails
Jarhead Offroad light covers
31x10.5R15 RedLetter Grabbers on Blackrock Dunes
L.O.S.T #KD098632

I got the JBA bolt on 4-link. Tom, or anyone else that can answer, I have a 4" JBA lift. The 4-link instructions say to cut the rods to length, and that they are long enough for 8" of lift. Also says that 17.75 center to center on the rod ends would equate to stock length. Without cutting, the center to center, with the rod ends run all the way down it 19.5". What is the center to center distance for a 4" lift, and how much did you cut off to get there?

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JBA 4" lift, IRO Tri-link w/ wwdiesel bracket, JBA sliders, 235/85-16 Goodyear Wrangler Duratracs, Mercedes Benz forged ultralight wheels, Weeks stage 1 and 2, Weeks lift pump and harness, Weeks battery tray and AGM battery, GDE tune, Suncoast TC, updated front pump, HDS 001 T-stat, ARP studs, Front and rear Detroit/Eaton Truetrac LSD.

Pinion angle? I'm trying to determine the proper pinion angle before I go and cut these rods on the JBA 4-Link. I'm pretty sure that on a conventional slip yoke driveshaft (no cardan joint) the pinion angle needs to be parallel with the transmission output shaft, but I kinda remember JBA telling me to have the pinion point to the output of the trans, which is my understanding for a cardan u-joint and not a stock slip yoke type single joint on each end. Any thoughts? I would really hate to cut these shafts too short. Kinda wishing I had either gone with the IRO/Whitby modified set up, or just gone to the junkyard and got a replacement cast piece and stuck with the y-link adapter.

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JBA 4" lift, IRO Tri-link w/ wwdiesel bracket, JBA sliders, 235/85-16 Goodyear Wrangler Duratracs, Mercedes Benz forged ultralight wheels, Weeks stage 1 and 2, Weeks lift pump and harness, Weeks battery tray and AGM battery, GDE tune, Suncoast TC, updated front pump, HDS 001 T-stat, ARP studs, Front and rear Detroit/Eaton Truetrac LSD.

on mine with 4.5 inches of lift

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

Thanks Tom, I just finished mine up, and the length of my links looks similar to yours. The pinion is not perfectly parallel to the tail shaft, but I think it is much closer than it was with the y-link adapter.

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JBA 4" lift, IRO Tri-link w/ wwdiesel bracket, JBA sliders, 235/85-16 Goodyear Wrangler Duratracs, Mercedes Benz forged ultralight wheels, Weeks stage 1 and 2, Weeks lift pump and harness, Weeks battery tray and AGM battery, GDE tune, Suncoast TC, updated front pump, HDS 001 T-stat, ARP studs, Front and rear Detroit/Eaton Truetrac LSD.