I replaced the ball joints just over a year ago. They are worn out already. What have you had luck with?

 

I have 163,000 miles on Synergy HD ball joints, greased at each 3,000 mile tire rotation.

 

I have Rare Parts but less than 10k on them so they are still pretty new. No complaints as of yet.

 

You may already know this, but just in case: The spec on the lower ball joint is less than .050" vertical play. Here's a pic of checking it with a dial indicator. A lot of people, including professionals and u-tubers, seem to expect near zero. My Jeep has a bit less that 0.040" and it drives just fine -- And that's 176K miles on stock units. I'd bet that if I asked a bunch of shops to check them, 8 out of 10 would say they were toast without ever taking a real measurement.

 

I just replaced the axles in my 2007. I was running Synergy after going through a couple sets of OEM style BJs (it took a couple years for the aftermarket to offer upgraded BJs). They had about 150K miles on them. Maybe more. Anyway, I did grease periodically. My mechanic who swapped the axles for me mentioned that the old BJs were worn out. I'm not sure if he measured or had just checked for movement. I had also never noticed any problem. And, even with the new Dynatrac BJs that came in the front axle, I can't really tell any improvement with the steering or other performance. It feels as good as it has always felt.

 

Big X factors are tire/wheel/backspace/weight combo, local roads, and general use. You haven't really indicated those. What brand did you replace with previously? Some folks like Mr. T have been fine with factory for a long time, and others will blow through BJs like crazy.

+1.

If the jeep is moderately or heavily modified and I was keeping it for a good while there is no doubt I'd buy Rare Parts. Most people scoff at their price, but BJs are an important steering component and are a leading cause of wobble issues, right behind track bar bolts and joints. I think a lot of folks view wobbles ad a nuisance rather than something that could easily cause a fatality in the wrong situation.

I wouldn’t dare disagree with you on technical specs, but I would say everyone’s build could react differently to various amounts of play. I can only speak to my personal experience and what I’ve seen first-hand on friends’ jeeps, but every time I’ve had a bad BJ I’ve had obvious symptoms that lead me down the path of inspecting, and the cure was always replacement or rebuild. I feel like my heavy tire/wheel combo combined with pitiful pothole-littered roads around me surely doesn't help my particular situation. I think most folks talking about bad BJs are similarly having an obvious issue (rather than it being a routine maintenance check) and that is often the smoking gun. I do totally agree that shops would rarely if ever take an actual measurement.

Knock on wood, I haven’t had a BJ issue since my nightmare rebuild in 2018, though the jeep seems to get less use these days and is more of a toy.

The only ball joints I've seen a performance difference with were Rare Parts, and it was only a difference in how easily that steering wheel returned to center vs almost every other BJ having some break-in period. Even with Dynatracs I had a break-in period when they were new, and after a rebuild.

 

I have Dynatracs now with mine...but had about 4-5yrs on my Teraflex ones and they were great too. Both are good to use...as are Synergy.

 

I replaced them with Rough Country. 2015 JKU 35 inch tires. Mostly a daily driver but lots of city driving. And the roads here are junk. I'm thinking about going with Terra Flex. They are definitely out of spec.

 

I'm running the Dynatrac HD ball joints and they have been great. And when they do wear out they are rebuildable. Highly recommend.

 

Dynatracs are super expensive, but they are beasts. I went through ball joints every few years until I just spent the money. Just make sure you do a touch of grease on the bottom ones every other oil change. Worth every penny, but was hard to press the submit button on the order!