I'm new to the forum and have searched for an answer but haven't hit upon this question exactly--

I have a 2003 V8 4Runner Sport with approximately 150,000 miles. I drive on some really rough roads during hunting season, and my lower ball joints are beginning to go (the XREAS system is also now shot, but that's another story). I have a local mechanic who will replace them, but I want to make sure I know what's going on and that he gets the right parts. From my research, I'm confused about when Toyota switched from the 3rd generation-style design of the LCA/LBJ with the ball on top of the LCA and under tension to the later design (4th gen?) with the ball below the LCA and under compression. Whenever the design change occurred, I've looked at the LCA/LBJs on my 2003 and it's definitely of the later design with the ball below the LCA. What do I need to tell my mechanic to order?

Thanks in advance.

I would go to RockAuto.com and order the parts yourself and then take them to the mechanic. RockAuto is pretty good about only presenting you with correct options for your application. You shouldn't need to know anything more about your truck than you already do to get the right options plus you'll avoid the mechanic's upcharge on the parts.

Thanks for the response and advice, but what I'm looking for is the answer to my question of whether the 2003 originally came with a lower control arm with the lower ball joint mounted with the ball on top or the bottom of the arm. I'm getting conflicting information about when Toyota changed the design when I search this question on the web. Some say this is a 3rd generation design, but elsewhere I see references to the change occurring in 2005. I'm the second owner of this 4Runner so I don't know what was originally on the vehicle. I'm trying to minimize downtime by making sure I get the right part ordered to start with. I generally agree with the sentiment to buy your own parts, but in this instance there won't be a markup.

What I was saying about RockAuto wasn't for the purpose of saving you money, although it would. I was suggesting that you use it to answer your question. Go in there and enter your vehicle information, look at the options that are filtered down to only apply to your vehicle, and then look at the design of the ball joints. They will all be the same design one way or the other so you can look at the pictures to answer your own question definitively.

What I mean is that you won't see a mix of different style ball joints and then get confused about which exact one you need. There will be only one style presented to you and that one style will be what you are looking for.

4th gens (2003-2009) all use the 4th gen style LCA/ball joint. There was no carryover of the 3rd gen design to the 4th gen models.

I think what you are getting confused about is the either the addition of VVTI and the 5-speed sealed auto transmission for the 2005 and up models or the mid-gen refresh that occurred between the 2005 and 2006 models. The mid-gen refresh included subtle changes, most notably different headlights, fender shape, tail lights, and a few other minor things.

LCA/ball joints and all other suspension/drive train components remained relatively consistent throughout the 4th gen run.