Dimensions of 1999 factory upper control arm ball socket plus SB-3841 replacement attached

ccasey · Jan 26, 2019

I'm replacing front suspension parts and found multiple threads on replacing the ball joint in the lower control arm, but conflicting info on the upper control arm ball joint. Most threads said replacing the UCA ball joint was only possible by replacing the entire UCA. Two threads mentioned that there was a viable replacement they had used for the UCA ball joint via Sankei 555 part # SB3841.

My plan was to find SB3841 to see if it measured up (sorry) but when I removed my UCA, i saw a crack in the housing, so I'm ordering a new UCA. That said, I removed the ball joint anyway and am attaching the measurements I made in case someone later wants to see if SB3841, or a future part, will fit. In case the picture gets lost, the face of the flange to the tip of the threads is 84mm. The support flange has a 59.5mm diameter, and the part that gets pressed into the control arm has a 46.25mm diameter.

ccasey · Jan 28, 2019

I went ahead and bought the SB-3841 ball joint and measured it. It will fit in the upper control arm. See pics below.
If you are replacing the bushings 48632-60010, for either control arm 48630-60010 left, 48610-60030 right, consider the ball joint as well. I got it from Napa for $38.49 (Jan 2019). It’s made by Sankei and is their Three Five (555) brand.
The only noticeable difference between the two parts is that the Sankei only has two holes drilled through the thread for the cotter pin while the Toyota version has four holes.
FWIW, the Sankei weighs 418 grams and the Toyota weighs 404 grams.
The functional difference between new and old is huge - I can rock the old ball back and forth in the old socket fairly easy. I can’t budge the new one by hand. I did put them both in the vice to measure torque needed to spin them, per page SA-76 in the repair manual. I don’t have a beam torque, but using a click torque as a proxy, the old ball was way less than my 20 in-lbf wrench minimum while the new one was +/- 26 in-lbf, in line with the upper end of the spec range (2.6 to 26) shown for the lower control arm ball joint.