In which we discuss knurled ball joints

[hear]

I did the ball joints on my 97 tonight. I had the spicers in hand, but imagine my surprise when the ones I pulled out were knurled. At one time I thought I read that once you used knurled you HAD to stay with knurled but I don't know if that's fact or just an old wive's tale that's been repeated over the years.

The bores on the passenger side had slight indentations from the knurling, but nothing that would even catch a fingernail. The bores on the drivers side didn't have much in the way of marks, which is what has me worried. I've done like 7 or 8 sets of ball joints so I have a decent feel for how much effort it takes in general, but also know that it can vary quite a bit from one jeep to the next. These were definitely among the easier ones to get out & back in (yes, I put the non-knurled spicers in), but I still had to work the press a little. It wasn't like they just slid in/out.

So I guess my questions are
(a) once knurled always knurled? Or nah, or does it just depend?
(b) if a knurled ball joint didn't leave indentations in the bore does that mean the bore is already worn out?
(c) if a knurled ball joint did leave indentations in the bore.....I don't even know what question I should ask.

I have it all back together, but haven't driven it because it's 1am. I'm not afraid to drive it as-is, but I would love some second opinions other than the low-effort replies like "better safe than sorry" without any science.

 

[TheBoogieman]

If it's tight, it's right. Goes for ball joints and women.

 

[mjbcomp]

According to the interwebs (take this with a grain of salt. It was my very first Google hit)...

Some aftermarket ball joints use knurling to help seat the ball joint more, it's really unnecessary. However, once a knurled joint has been installed, it scores the inside bore of the axle C and then you are stuck with using knurled joints forever after that.Jan 24, 2018

 

[Weasellee]

Once you go knurled you never go back. I don’t believe it is true always

 

[Mike_H]

I went from knurled back to spicers. My bores were slightly scored from the splines on the old Ball Joints. I dimpled the surface of the spicers with a punch when I installed them, just to be sure...Been driving fine now for a few hundred miles.

 

[machoheadgames]

I had teraflex ball joints (junk) in a Dana 30 for several years. When they were removed and tried to go back to Spicer, the Spicers went in with pretty much no effort. Some people have better luck and I’m sure not all knurled are the same.

It’s not so much about the marks in the hole, it’s about the overall larger ball joint body stretching the holes out which is when they then don’t fit Spicer as well as they once did.

My Teraflex ones took a lot of effort to install. I’m sure that stretched out the hole.

 

[mrblaine]

I did the ball joints on my 97 tonight. I had the spicers in hand, but imagine my surprise when the ones I pulled out were knurled. At one time I thought I read that once you used knurled you HAD to stay with knurled but I don't know if that's fact or just an old wive's tale that's been repeated over the years.

The bores on the passenger side had slight indentations from the knurling, but nothing that would even catch a fingernail. The bores on the drivers side didn't have much in the way of marks, which is what has me worried. I've done like 7 or 8 sets of ball joints so I have a decent feel for how much effort it takes in general, but also know that it can vary quite a bit from one jeep to the next. These were definitely among the easier ones to get out & back in (yes, I put the non-knurled spicers in), but I still had to work the press a little. It wasn't like they just slid in/out.

So I guess my questions are
(a) once knurled always knurled? Or nah, or does it just depend?
(b) if a knurled ball joint didn't leave indentations in the bore does that mean the bore is already worn out?
(c) if a knurled ball joint did leave indentations in the bore.....I don't even know what question I should ask.

I have it all back together, but haven't driven it because it's 1am. I'm not afraid to drive it as-is, but I would love some second opinions other than the low-effort replies like "better safe than sorry" without any science.

The only thing that matters is how much interference there is between the bores and the body of the ball joints. If there is the correct amount of effort required on the press to install them, no problem, is there isn't, problem.

 

[AndyG]

Once you go knurled you never go back. I don’t believe it is true always

Here in the south it was “once you go black you can never go back....”

Knurled ball joints sounds painful.

 

[hear]

If there is the correct amount of effort required on the press to install them, no problem, is there isn't, problem.

Is there any quantifiable measure to determine what this is? As I said, these were on the easier side (possibly the easiest) of all the one I’ve ever done.

Out of curiosity, what are the recommended ball joints if it turns out I need to go with some knurled ones?

 

[P man]

Is there any quantifiable measure to determine what this is? As I said, these were on the easier side (possibly the easiest) of all the one I’ve ever done.

Out of curiosity, what are the recommended ball joints if it turns out I need to go with some knurled ones?

I cant imagine there being a torque spec I would believe it is all in the feel.

 

[mrblaine]

Is there any quantifiable measure to determine what this is? As I said, these were on the easier side (possibly the easiest) of all the one I’ve ever done.

Out of curiosity, what are the recommended ball joints if it turns out I need to go with some knurled ones?

How would you quantify it? Which grease are you using on the press screw threads? What temp is it so we know how much friction is being added or taken away due to the change in viscosity of the grease? What is the surface condition of the screw threads? How much lube is in the cup at the end of the screw? Are the adapter cups at the correct angle? Is the ball joint perfectly square to the bore when you started? Is there any surface condition variables on the ball joint that will affect the friction going in or out? All of those affect turning force on the press screw.

In other words, there is no easy way to quantify and the answer is one you already know. If they were not too easy to get in, you wouldn't have got on here and posted about it. You already know you have pull them and dimple the bodies and get some 609 Loctite on them, you just wanted someone to tell you that it will be fine. I'm not that guy.

 

[TJ Jim]

One side of mine had knurled joints. Like mentioned above I just pinged the sides of the smooth joints and pressed them in. 30,000 miles later I’m still alive and the jeep alignment is perfect.

 

[imahnu]

You already know you have pull them and dimple the bodies and get some 609 Loctite on them, you just wanted someone to tell you that it will be fine. I'm not that guy.

I did this exact process off of @mrblaine recommendation when I was building my HP30. I had one side with enough space that the ball joint could easily drop in halfway and then barely had to be pressed the other half. Dimpling them and the 609 loctite has held up over the last year with zero issues. The press fit was back to what it should’ve been.