Another BK081 vs BK055 spherical bearing fyi

[Robottrainer]

So being the curious guy I am and getting ready to do the bearing swap this week, I bought both bearings to see what the difference is.

I set up a test rig in my 20 ton press and clamped the outer shell of both BK055s in two v blocks at a force of 1 ton. I put a 5/8 hardened bolt and nut through the bearings and spacers and torqued it to 130lb ft.

One bearing was stiffer than the other at first. I checked to make sure the ball rotates as you turn the bolt. After working the stiffer one for about 15 minutes by rotating it, I got the force needed to turn it to 56 lb.ft. it does creak when you turn it slow and it did get warm. The BK081s turn by hand without tools.

I like the beefy 055s but jeez they are stiff. I like the shoulder and snap ring idea too. But jeez they are stiff

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[Radiation Joe]

The 55s loosen up with about 500 miles of "exercising" them. I'd recommend them over the 81s any day.

 

[thelostotter]

This confirms the sensation I've got since I installed BK055 in the rear and the Steeda front spherical bearings. The car is extremely planted over medium-large bumps, much more than before the upgrade, but they do appear to have quite a bit of stiction as I feel a sensation of the suspension hardly working at all over small bumps. I figure they will loosen up with more miles, and you proved that.

Other than the perceived stiction, I have zero NVH from either bearing by the way, a pleasant surprise.

 

[Radiation Joe]

The Steeda sphericals in front gave me the same stiction issue as the BK 055s in the rear, but it only lasted a day or two.

 

[Robottrainer]

The Steeda sphericals in front gave me the same stiction issue as the BK 055s in the rear, but it only lasted a day or two.

I just did mine. I find in normal (magnaride) mode it's a bit stiffer. Funny thing. It seems to come from the shocks and not the bearing. When undue the shocks it move nice. Cant figure out why the shocked are slightly stiffer.

 

[Robottrainer]

I just did mine. I find in normal (magnaride) mode it's a bit stiffer. Funny thing. It seems to come from the shocks and not the bearing. When undue the shocks it move nice. Cant figure out why the shocked are slightly stiffer.

Another thing to be aware of. When you are loading the control arms, I found if the try to do it close to the pivot points, the control arms only move about 60-70% of ride height. Its probably sufficient as the Ford manual says to move it abut 20mm. Ride height is bestThe shocks (at least the magnaride ones) are a bitch to compress. Jack it closer to the outside. Makes sense as that gives the greatest leverage.

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