Rear upper arm ball joint failure.

capatob · **Joined:** Wed Aug 30, 2017 5:33 am **Posts:** 4

On my third upper rear arm ball joint on my KJ. Lasts about 1 year or 20 thousand kilometers before it gets to the stage of being difficult to drive. Can only get a genuine Jeep ball joint in Australia. Had the same problem with the genuine Jeep bushes until after market poly (super pro) ones were fitted. Learnt my lesson the hard way so the rest of the suspension is after market with no problems. There is no reason why this should be happening, it has only been raised slightly and does no off road work, just run to work and back on the bitumen. Jeep won't come to the party as they warrant the part for 10 thousand kilometers only. Where can I get one that lasts? :furious:

papaindigo · **Posted:** Wed Aug 30, 2017 8:47 am

Do you mean the boomerang shaped rear upper control arm and if so are you replacing the whole thing or just the ball joints? FYI a Moog replacement ball joint is available in AU at http://www.ebay.com.au/itm/JEEP-CHEROKE ... 1881220629

LarryK · **Joined:** Thu Apr 27, 2017 12:07 pm **Posts:** 5

Rockauto has same part by Moog for $48.00 US

tjkj2002 · **Posted:** Wed Aug 30, 2017 11:42 pm

Improper pressing of the ball joint can lead to reduced life and I can say that is one ball joint that is very hard to press in properly.

Best to buy a whole new upper tri-link then trying to press in new parts.

GordnadoCRD · **Posted:** Thu Aug 31, 2017 12:04 am

I have been under the impression that complete Mopar tri-links were the best, considering money-per-mile. Is this wrong?

jws84_02 · **Posted:** Thu Aug 31, 2017 8:32 am

I'll be another one that agrees the big ball joint is difficult to press in. I've tried on two different ones and just ended up buying the whole complete boomerang

WWDiesel · **Posted:** Thu Aug 31, 2017 12:45 pm

jws84_02 wrote:

I'll be another one that agrees the big ball joint is difficult to press in. I've tried on two different ones and just ended up buying the whole complete boomerang

The single ball joint can be pressed out and a new one pressed back in with a proper hydraulic press & press tools and an experienced operator! :roll:

tjkj2002 · **Posted:** Thu Aug 31, 2017 1:17 pm

WWDiesel wrote:

jws84_02 wrote:

I'll be another one that agrees the big ball joint is difficult to press in. I've tried on two different ones and just ended up buying the whole complete boomerang

The single ball joint can be pressed out and a new one pressed back in with a proper hydraulic press & press tools and an experienced operator! :roll:

Finding the correct cup for said ball joint is nearly impossible unless you order from the dealer,it's like some oddball number between 5.5" and 6".

I've seen most warp that tri-link trying to press in/out the bushings/ball joint.

APC9199 · **Posted:** Fri Sep 01, 2017 5:39 pm

I wonder how many people have had this part fail repeatedly or prematurely?

I just ripped a local shop a new one because I paid them to replace nearly every bushing under the Jeep and they DESTROYED the boomerang when they put the ball joint back in. I feel a little bit bad after reading this, but I also don't because they previously left one of the bolts loose which fell out on the highway at 75mph! They also didn't tell me they butchered it, which tells me they were more interested in trying to hide it than telling me the truth.

Anyway, I have access to quite a bit of fabrication equipment and have been considering making a welded box-beam style boomerang with a heavier wall where the ball joint gets pressed in. I would add some hefty set screws just to secure the joint better. I also want to pour some custom urethane bushings for the other end to get rid of some of the loose feeling on the highway and prevent having to change them every 20k miles!

DocB · **Posted:** Fri Sep 01, 2017 8:30 pm

I have a Moog K500190 rear upper ball joint that I am planning on installing here pretty soon, and I got this one because of Moog's quality (used them on the front) and because it is supposed to be greasable.
Problem is that there is no Zirc grease fitting on it. It is their top of the line "Problem Solver, greasable"
So how do you grease it periodically?

tjkj2002 · **Posted:** Fri Sep 01, 2017 8:44 pm

DocB wrote:

I have a Moog K500190 rear upper ball joint that I am planning on installing here pretty soon, and I got this one because of Moog's quality (used them on the front) and because it is supposed to be greasable.
Problem is that there is no Zirc grease fitting on it. It is their top of the line "Problem Solver, greasable"
So how do you grease it periodically?

You don't.

tjkj2002 · **Posted:** Fri Sep 01, 2017 8:46 pm

APC9199 wrote:

I wonder how many people have had this part fail repeatedly or prematurely?

I just ripped a local shop a new one because I paid them to replace nearly every bushing under the Jeep and they DESTROYED the boomerang when they put the ball joint back in. I feel a little bit bad after reading this, but I also don't because they previously left one of the bolts loose which fell out on the highway at 75mph! They also didn't tell me they butchered it, which tells me they were more interested in trying to hide it than telling me the truth.

Anyway, I have access to quite a bit of fabrication equipment and have been considering making a welded box-beam style boomerang with a heavier wall where the ball joint gets pressed in. I would add some hefty set screws just to secure the joint better. I also want to pour some custom urethane bushings for the other end to get rid of some of the loose feeling on the highway and prevent having to change them every 20k miles!

Jeepin By Al makes a bolt on(and weld on) 4 link replacement for that rear tri-link,no more bushing or a ball joint.Granted it comes with Heim joints which suck but should be easily be able to swap out for some Johnny Joints.

APC9199 · **Posted:** Fri Sep 01, 2017 9:14 pm

tjkj2002 wrote:

APC9199 wrote:

I wonder how many people have had this part fail repeatedly or prematurely?

I just ripped a local shop a new one because I paid them to replace nearly every bushing under the Jeep and they DESTROYED the boomerang when they put the ball joint back in. I feel a little bit bad after reading this, but I also don't because they previously left one of the bolts loose which fell out on the highway at 75mph! They also didn't tell me they butchered it, which tells me they were more interested in trying to hide it than telling me the truth.

Anyway, I have access to quite a bit of fabrication equipment and have been considering making a welded box-beam style boomerang with a heavier wall where the ball joint gets pressed in. I would add some hefty set screws just to secure the joint better. I also want to pour some custom urethane bushings for the other end to get rid of some of the loose feeling on the highway and prevent having to change them every 20k miles!

Jeepin By Al makes a bolt on(and weld on) 4 link replacement for that rear tri-link,no more bushing or a ball joint.Granted it comes with Heim joints which suck but should be easily be able to swap out for some Johnny Joints.

http://jeepinbyal.com/liberty-2002-2007 ... -link.html

Holy crap! Expensive much?!

I don't like the idea of welding anything to my axle either. Maybe a more "modular" tab system of some sort, but definitely not that thing. I like the idea, but that seems overkill, and they even state that it is primarily for those who have damaged the ball joint mount on the differential. My idea is to use similar construction to that unit, but use the existing mounting points.

tjkj2002 · **Posted:** Fri Sep 01, 2017 10:01 pm

They make a bolt on version.

The price is not bad,my controls alone retail at about $1500.

DocB · **Posted:** Fri Sep 01, 2017 10:29 pm

What do you mean "You don't".
It's advertised as greasable.

tjkj2002 · **Posted:** Fri Sep 01, 2017 10:37 pm

DocB wrote:

What do you mean "You don't".
It's advertised as greasable.

That one is not,they use the same add for all there problem solver joints,which alot do not actually have a grease zerk.

DocB · **Posted:** Fri Sep 01, 2017 11:45 pm

Thanks for the info TJ.
Still, I will call Moog on Tuesday. The product description of being greasable is the reason I went out of my way to get this joint.
I would hate to have to tap this joint to thread in a grease fitting. The small round silver colored tit on the bottom of the unit rotates freely so drilling and tapping could be challenging.
BTW-that plug does not pull out.......yet.

capatob · **Joined:** Wed Aug 30, 2017 5:33 am **Posts:** 4

papaindigo wrote:

Do you mean the boomerang shaped rear upper control arm and if so are you replacing the whole thing or just the ball joints? FYI a Moog replacement ball joint is available in AU at http://www.ebay.com.au/itm/JEEP-CHEROKE ... 1881220629

I think I'll go with this first before trying anything else as I have poly bushes fitted to the other end of the boomerang upper control arm which seem quite good. I hope a new boomerang is not the only way out! Thanks for the info!

tommudd · **Posted:** Tue Sep 05, 2017 9:30 am

Never trust those cheap tri-links, had two lasted less than 3 months.
Many have tried pressing in new ball joints either to have the metal bend or again only last a few months
only way is the MOPAR tri-links or the bolt on JBA one. I've been using them for a long time, well before they even came out

thermorex · **Posted:** Tue Sep 05, 2017 8:15 pm

For few more bucks, get the whole wishbone from napa and there are no issues with ball joint or installation. The ball joint could be pretty stuck in the Diff case, I had a very hard time taking it out (salt + cleveland reasons) and ended up butchering the ball joint and cutting the ball joint bc I lost my patience. If you wanna go crazy offroading like tj and Tom, then I'd spend the money and get a 4 link.

Rear upper arm ball joint failure.

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