Upper Ball Joint Blues

i'm totally perplexed. i'm installing new OEM upper ball joints (

$52 43310-39016 Genuine Toyota Parts - Joint Assy,Fr UPR Ba (43310-39016)

43310-39016), but they don't fit in the top of the knuckle. toyota and the internet says i have the correct UBJs.

i measured the OD of both new UBJs and the ID of both of my knuckles. both UBJ's were the same size and both knuckles were the same size, but there was a .010" interference between the respective parts. in my experience, that's way too much. should be more like .003". the ball joints i pressed out were .005" smaller than the new ones, but not sure if life in the knuckle would impact them. i assume not, but maybe?

despite my opinion about the appropriate amount of interference, i actually only realized the issue after attempting to press one in. it wasn't going smoothly, so i stopped and pushed it back out. the metal on the UBJ was noticeably sheared / deformed by the knuckle around the entire perimeter. so it's not that it wasn't centered or crooked or something.

i have no clue what to do other than attempt to machine down the UBJs. but that seems kinda nuts to me. so hoping for a little TW wisdom!

 

They're not fun to press in and out usually. It's a tight fit. You could freeze em in the freezer overnight and they may shrink a thou or two. Likewise with heating the spindle a bit to enlarge it

 

Where did you source the parts from? Lots of fake Toyota parts on Amazon/eBay

What are you using to press them in?

 

good thought. i was wondering about how much the freezing would help, but i was hoping not to heat the knuckle because i wanted to apply some anti-seize. might be my only option though.

 

i got the parts directly from mcgeorge toyota. using a 20 ton press.

 

a couple small updates:

- i bought some UBJs from Napa made by 555, and they are the same OD as the new toyota UBJs. so no help there.
- i did the math for freezing and heating the parts, and it would reduce the interference by about .006". that would would bring it within range, but once the temps equalize the outward pressure on the knuckle would be considerable. without knowing exactly what that knuckle is made from, the potential for failure would be beyond my comfort level.

it probably sounds like i'm being too nerdy about this, but the simple fact is that UBJ will not press in without damaging the parts. so that just can't be right.

anyone have some new toyota UBJs that match my originals with an OD of about 1.701"?

 

The knuckles are forged steel

 

Press them in and send it.

 

mcgeorge toyota has reasonable prices

 

I am currently having the exact same problem with my 1998 tacoma 4WD with locking hubs. Did freezing work for you?

 

I used a big pneumatic impact gun on the ball joint press. Didn't go in straight at first, but it straightened out after using sufficient force.

 

i forgot to follow up after my last post: essentially, just press them in and don't worry about. i didn't freeze or heat anything. i found a thin metal ring jammed between UBJ and the knuckle, and realized that the knuckle shaved the UBJ down when it was pressed in by the factory. i replaced the passenger and driver side UBJ, and found the same ring on each side. so i pressed them in, and that same thin metal ring was created each time.