Returd

I'm investigating modifying stock control arms to make the ball joint replaceable. If successful I'll share my info. I can use some help sourcing a replacement ball joint.

I took a control arm, machined the bottom cup off the ball joint socket and pressed out the "non serviceable" ball joint.

The socket will need some machining to accept a new joint, there's a taper in the bore etc. Attached is a sketch of the overall dimensions. There is leeway in that the socket can be bored to suit the new ball joints.

I figure there's a lot of interested folks here that may make my search for a replacement joint quicker. look over the sketch and point me to any potential winner replacement joints. The more readily available and inexpensive the better (I'll lean towards a high quality BJ over a cheapo).

have at it gang

logix7

im sure theres something thatll fit. i cant see any machining being required though. its no comparison but, i replaced my "non-serviceable" upper control arm balljoints on one of my hondas with no problems

RXRodger

iTrader: (2)

I found a thread on here a year or so ago (thread was older than that) where a guy had researched all of the Toyota ball joints and all of the shank tapers, threads, lengths, ball joint body diameters, etc. His conclusion was there wasn't anything that would fit that wouldn't require some additional machining and reinforcing the outer area of the arm where the ball joint is. I think he even expanded to Subaru and some others, not much luck. Given the machining and risk of welding on a control arm it just didn't seem feasible. But, party on, maybe you'll figure it out. I hope you do, it just seems like something would be out there.

KahnBB6

iTrader: (5)

^^ I recall there was a thread about this but I don't remember what it was called. The OP did try a lot of different alternatives before he stopped. It would be nice if there were a proven way to service them with a solid part rated for the load.

For now we can still get replacement OEM front LCA's. Figs Engineering makes an aftermarket direct replacement front LCA set with serviceable ball joints but they aren't cheap.

RXRodger

iTrader: (2)

Yep, by the time you buy the bushings to go in old arms, then buy the whatever ball joint you find that would fit you are less than $100 away from the cost of supra arms so there just doesn't seem to be much incentive.

Returd

except the ball joint would be serviceable, the second and all subsequent replacements significantly cheaper. That and I just feel up for the challenge in this one.

I'm not familiar with bushing costs or cost of supra arms.

RXRodger

iTrader: (2)

I get the challenge thing, it is why this subject is interesting. Nobody has done it. However, it's something you would probably only do one time per car so the reward probably won't pay off. The bushings and ball joint most likely need to be replaced at the same time. The bushings depending on what you buy are going to cost $100/set maybe more. The work to put these in are time consuming, not overly complicated but takes time to burn out, clean up the arms and metal bushings, etc. The ball joint cost depends on what you end up finding. The machining work costs something, lets just say $50-$100 unless you have that ability/equipment already. The Supra arms are about $270 each online. So, there is your comparison. It is definitely a worthwhile thing to investigate, I just think most people go through the math and figure the time and just take the easiest way out and buy the Supra arms.

Returd

where do you get supra arms at that price?

RXRodger

iTrader: (2)

This is one option, but there are several that offer similar prices.

NCpilot

How long are your lowers lasting on the chumpcar?

RXRodger

iTrader: (2)

I replaced them at the beginning of the 2016 season, they are still hanging in there at the moment, but was considering replacement this winter. I don't see anything to warrant replacement now, but given the stress they see I think it is getting close to time.

Edit: These front lower control arms and the rear toe arms seem to be the worst wearing arms. I just replaced the toe arms with new ones from amayama.com (oem).

NCpilot

I remember you posting about that. I am probably going to come up with a frankenstein toelink...wish those Figs front lower arms were not so expensive.

Returd

I visited my stock car friend last night. He's got all sorts of suspension goodies.

Looks like I can make a replacement but I'd have to have a custom ball joint machined. The ball joint would be about $40, machining additional. I have a local machinist who is capable (and inexpensive). I'd go with a screw in cup and some other custom pieces. Considering I have two old arms I could do this and add them to my spares inventory.

I got pretty much the same answer for a few trick suspension shops I contacted.

There could be an advantage to this in that I could make a longer ball joint which would correct some of the geometry compromises from lowering. This would also mean changes needed for the upper. For my gently driven street car this seems over the top.

I'm going to veto the above option and shelve this effort. If someone wants to pick up the torch and finds a ball joint with dimensions that look close to the post #1 sketch let me know. If a promising option is found I'll continue the effort and post results. There is a bit of material that can be removed yet from the ball joint socket. I'll keep the arms for a couple of months before scrapping.