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I have been looking for some replacement pivot balls for an old Bullet I am trying to get to running condition. Originally these were available as Traxxas part number 1642 which included both the pivot balls and rod ends. This part number is no longer available but I see other offerings from Traxxas that are similar but appear to be different sizes. I also see Traxxas part number 7028 which physically look similar on line but I am not sure of the diameter. Is there a direct replacement currently available for the balls or am I going to have to go with a different set of balls and rod ends? As this is not a restore I am not concerned about a direct match just looking for a functional replacement.

Thanks,
George

pretty sure the ball sizes are the same. they are slightly different in that they have a lip on them instead of just the small straight section.

these guys should fit no problem:
https://www.ebay.com/itm/131320965236?_trkparms=ispr%3D1&amdata=enc%3AAQAFAAAAkJE00I%2Be3v6NWgVyqxI93tRnwXCyU1wOf8HcdkTP4OpvWqOtsreshX%2FD7ZKf3PZkaHlMvnjkPV8tcYqPKVk6br57qFD7ex4vPPz0bk8G7HE8AoHBVploONzNyW58gTuglz86%2FM2My3n3ml4HwMwgKB%2F9BBkzu5xurE2Ow1pOhfEc864qj1dSaHHK36wUSfiRAQ%3D%3D&chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=131320965236&targetid=1262376589176&device=c&mktype=pla&googleloc=9007181&poi=&campaignid=12873834640&mkgroupid=120270032814&rlsatarget=pla-1262376589176&abcId=9300536&merchantid=6311274&gclid=Cj0KCQjw7pKFBhDUARIsAFUoMDYnfUSkOE0_K-GS2Qx-aAjWqgJEtfxX5cc126cyEshXiufws9AlgvIaAlMeEALw_wcB

I only find one reference to the size of the 7028's and they call them a 4.5mm ball making them too small. I use the 1942 rod end set, they are replacements for the old school ends. That part number goes back to the Eagle.

I have a 1942 set in front of me. The pivot balls measured 5.75mm.

Thanks everyone. The original balls look to be 5.7mm in diameter and 6.33mm (1/4") in length. While they are similar in style to the 7028's it appears they are too small.

juicedcoupe - Can you tell me if the length of the 1942 balls is the same?
Thanks,
George

Placing all the washers on the on sides opposite the screw heads bitd rivaled the tediousness of all the E-clips! Dealing with those in the pits with excited little hands and beat-up Phillips head drivers.....those were the days!

gtrgeo wrote: ↑Wed May 19, 2021 5:22 pm Thanks everyone. The original balls look to be 5.7mm in diameter and 6.33mm (1/4") in length. While they are similar in style to the 7028's it appears they are too small.

juicedcoupe - Can you tell me if the length of the 1942 balls is the same?

Traxxas Pivot Ball.jpg

Thanks,
George

I measured 6.3mm.

I did mention above that they are the same overall but have a slightly different form. They are good replacement parts.

Thanks all for the suggestions and confirming dimensions for me. Looks like I can pick up the 1942 set for $7 at the local hobby shop so that works.

Thanks again,
George

I believe the 1942 set has the four round shank ends for the shock rods as well. They fit the underside of the spring cup and are slightly shorter as well. The balls in the 1942 kit fit the older style white and gen2 black rod ends. As previously discussed, they are a direct replacement save for the flared and ground flat ends that serve stabilize the ball and distribute the pressure when tightend against the nylon parts.

TRX-1-3 wrote: ↑Wed May 19, 2021 6:15 pm I believe the 1942 set has the four round shank ends for the shock rods as well. They fit the underside of the spring cup and are slightly shorter as well. The balls in the 1942 kit fit the older style white and gen2 black rod ends. As previously discussed, they are a direct replacement save for the flared and ground flat ends that serve stabilize the ball and distribute the pressure when tightend against the nylon parts.

This makes sense from what I am seeing. It looks like I would have enough to fit the whole car and have a couple of spares. I like the idea of the flat ends on the pivot balls as the straight cut ends on the vintage balls tend to cut into the arms making for a finicky fit especially in the front arms.
Thanks,
George