930 front hub conundrum
 

Gents,

Been a lurker for some time but I never did any real projects with my car....until now.

I guess a little back story to set the mood. Grab a beer and have a seat because this is kinda funny...

Last month I get the distinct pleasure of moving from South Carolina to California and I though "hey its a good trip for the Porsche". So I take a gander at the car and decide I need new tires since its a long trip (heading up to NJ to see family first) and I don't want any issues with the car. I take the car to my mech and tell him I'd like some new tires and install a bump steer kit and that I was going on a very long drive. We agreed to look over the car to identify any issues that may come up. I asked him to take a look at my right front suspension sis it seemed a little lower than the left.

That evening he calls me with the bad news. The strut went bad. The only thing they have in stock is a set of RSR's with 19mm raised spindles. I'm thinking this is great! I wanted to toy with the idea of coil overs and this helps get me there. So I spurge on them and he installs them over the weekend.

That following week I drive the car to NJ. No issues getting up there and no issues with the few times I drove it in SC. The car is driving well with the bump steer kit.

On my way to Cali I go! Headed towards Nashville for the night. Great place to stop if you ever get the chance. I was driving South on I-81 in the left lane on a newly paved section south of Roanoke VA. All of a sudden I feel a "pop". Kind of like a blown tire but not as loud. So I pull off the side of the road to check it out. As I'm on the way over there I start to think this doesn't feel like a blown tire. I get out of the car and this is what I see.
http://forums.pelicanparts.com/uploa...1516242502.jpg

The front tire is very close to resting on the inside of the fender. I'm thinking *****, I just replaced that strut. I call my Mech and he thinks it may be the torsion bar.

Well he may be right (I have not been able to pull out the torsion bar) but I found this instead

http://forums.pelicanparts.com/uploa...1516242598.jpg
http://forums.pelicanparts.com/uploa...1516242598.jpg

That is what I saw when I took off the front hub.
After cleaning it up a little this is what I have.

http://forums.pelicanparts.com/uploa...1516242673.jpg
http://forums.pelicanparts.com/uploa...1516242673.jpg
http://forums.pelicanparts.com/uploa...1516242673.jpg

There were huge chunks of metal all in the packing grease.

Now the questions.

What failed?
What could have caused this?
Is this due to a bad installation?
are the marks on the spindle a no go?
How do I get the bearing that has the arrow pointing to it off? I have tried to use a slide hammer with a bearing claw attached.

Here is another picture of the bottom of that bearing. There looks to be a grey film or something that looks like overheating indications???

http://forums.pelicanparts.com/uploa...1516250075.jpg

Now I will need to research what parts to get and look up old post on how to do this removal and installation of the bearings.

At least I got a new car out of it..I had to get a car in Roanoke and keep driving across the country.

spindle nut installed too tightly?

Well . . .

It looks to me like a simple small bearing failure . . .
Why = Mech may have used old bearing when they replaced the strut - and it just failed (?)
(or spindle nut too tight . . . )

I would replace the bearings and see what happens . . .

Very nice 930

Regards,

Do you have anymore pictures of those wheels? They look interesting , I like that gold with the grey.

Replace both bearings and move on

I would also guess that the spindle nut was overtightened and caused undue stress on the bearings, causing bearing failure. New bearings and making sure that you don't overtighten that spindle nut, would be the fix.

Here's the spindle nut on a 911 SC:

http://forums.pelicanparts.com/uploa...1516287836.jpg

Not the end of the world, simple outer bearing failure. As others have said, replace both, make sure spindle nut is loose enough per factory specs, and drive on.

Thanks guys. Now I’m going to continue to try and get the outer bearing off. It’s being a bugger. Thanks for the tip on the spindle nut, it did take a little effort to get off.


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Any tips or tricks to try and get that outer bearing off??


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3 jaw puller would work good.

You might want to check the tightness of the spindle nut on the other side too.....

Yeah I think I’m going to do the bearing on both sides....just to be safe.


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Well I got the inner race and bearing off. The outer just won’t move. This is my contraption to try and get it off. And additional ideas or tips? https://uploads.tapatalk-cdn.com/201...8bcb1cbbc9.jpg
I’m thinking of getting the impact gun out. *


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If that doesn't work, take a die grinder with a cutting wheel and cut the race almost down to the hub. Then, position a chisel on the cut groove and hit with a 5 pound sledge. Race is VERy brittle and will crack off.

That's also how you will need to remove the inner race, BTW.

Ok, it’s off! Does this look like the spindle is ok? Seems like the bearing fuzed to it.
https://uploads.tapatalk-cdn.com/201...cdb20d9ac5.jpg


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You won't really know until you get the old race fully off. Try chiseling it off or very light sanding with a die grinder until you're a C-hair from the spindle itself, then scrape off / sand off until you hit good metal.

Yep, looks like that spindle nut was too tight and spun on the spindle. Bummer...it's a small detail that caused a lot of headache.

spindle
 

I noticed the inner spacer/grease seal ring appears to be missing, did you remove it ?
Mike Bruns

That spindle/strut is toast unfortunately, due to the outer bearing race chewing it up. Yeah, where's the inner seal ring?

No one has mentioned it yet but have you checked the other side? It might have been tightened too much as well.

Check this.^^^ There is a spacer #901-341-623-00 that looks like part of the spindle and the mechanic probably missed it when swapping parts. The bearings seats too far in when it's missing.
I would tow the car back to him. He owes you a spindle and bearings.

What does the race inside the axle hub look like? I think you only showed us the race condition for the larger, inboard bearing that did not fail.

This Timken video is a pretty good one to show various types of bearing failures

https://www.youtube.com/watch?v=hVuReXrZ8Mg

Over the years we've seen some bearings that were not machined properly on the inside diameter and don't fit over the spindle. Someone could have forced one of those on there?

http://forums.pelicanparts.com/porsche-911-technical-forum/589906-new-skf-inner-front-bearing-doesnt-fit-spindle.html

Or you could have experienced a bearing that had its inner race spinning on the spindle too much. That race is supposed to stay put, like the outer race is pressed into the hub, and the roller cage rolls along the races. Rolling is important. I guess there can be instances of sliding, where the rollers are not spinning, and that's bad.

Agreed that spindle is toast and you need a new strut. That spindle carries a lot of load and you don't want any surface defects compromising it's strength. The load on the spindle will seek out that surface damage and crack/failure propagates from there.

The spindle is a nicely machined forged piece and very strong. But as these cars continue to age, we're going to see things break that normally wouldn't. Nothing lasts forever, even though Porsche generally over-built these cars in a lot of ways.

The inner spindle collar looks like it was there at initial disassembly. I think he unnecessarily took it off during the removal of the toasted bearing? See the above pictures.

http://forums.pelicanparts.com/uploa...1516242673.jpg

I think y’all are spot on again! I noticed last night looking at parts that I would need to get that there was no inner seal ring on this side. I think I need to have a talk with my mechanic about replacing that strut. Looks like multiple steps were not followed.

I have not checked the other side yet but just a wiggle of the tire confirms the hub is not as loose at the right side was. I will be doing that side also.


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If you want to see how all of the spindle/hub components come together on a 911SC, take a look at my thread. I did a full rebuild with raised spindles and new bearings. Lots of pics:

http://forums.pelicanparts.com/porsche-911-technical-forum/726309-78-sc-elephant-racing-suspension-rebuild.html

The inner spindle and a spacer were on the strut but that spacer was very loose. There also was no O ring on it.
https://uploads.tapatalk-cdn.com/201...98a50dce7c.jpg
This was also missing.


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This is the space I’m talking about.
https://uploads.tapatalk-cdn.com/201...a21839a7e2.jpg
The yellow arrow shows a lot of room between the seal and the race. That was before I did anything to the inner race.


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That video was very informative. Thanks for posting it and all the time you put into your reply. Looks like I need to talk to the mech now. Unfortunately I moved across the country so he can’t re-install new parts. I think I’ll have him purchase them and ship them to me to be installed. I’m starting to get an irrational fear of someone else working on my car.


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That's exactly why I did my own rebuild. Not only that, BUT one of my spindles also did not have that spacer when I pulled the hubs, and the bearing housing was tweaked.

Take a look here: http://forums.pelicanparts.com/porsche-911-technical-forum/726309-78-sc-elephant-racing-suspension-rebuild.html#post7180961

Here's the point in my build where I installed the two "hat" spacers onto the new spindles (I switched from stock Boge to Bilstein raised spindles by Elephant Racing):

http://forums.pelicanparts.com/porsche-911-technical-forum/726309-78-sc-elephant-racing-suspension-rebuild-11.html#post7248644

James,

Even a new collar/spacer placed on the spindle is going to have that space in there. That's just how it fits. That said, it's good to pack that void with grease. Reason being is the void provides a place for the grease to migrate into and that takes some grease away from the bearing.

The o-ring doesn't really do anything to hold the collar on there. It's intended to be a seal against grease leakage (when the grease separates and releases oil) seeping past the interface of the collar flange and the spindle. In all honesty the o-ring isn't critical to the install. You could put a small bead of silicone around the neck of the spindle and that would seal it better. Because I don't know that the o-ring really completely seals it all that well. The o-ring doesn't seem to tightly fill the void between the radiused fillet of the spindle and the collar flange. I could be way off base with this. Just a gut feeling.

The fit of the collar is a rather light press fit. Guys have been successful in driving it off the spindle with a hammer and punch. Or if you have a suitable size two jaw puller (usually have to grind/shape the pulling arm hook area for it to grab the edges of the collar) it doesn't require a lot of wrenching effort at all to draw the collar off the spindle with the puller. Reinstalling the collar goes really smoothly if you heat it up with a heat gun or toaster oven. Slips right on with no interference and doesn't take long to cool down and shrink fit itself in place.

Thanks for the tips for reinstall of the parts. I think I’ll get all the parts just to be safe since that’s how they designed it.

Well productive night tonight. I got both races out. The inner one was a PITA. It took a couple hours. Had to use a punch and just rotate the hub all the time. Patience was key here. The outer race came off in about three hits. Super easy.

Some have asked or wondered what was installed on the hub/spindle. Other than the bearing that failed and turned into about a million pieces....ok maybe about a thousand (no kidding there) here are the only parts that were on the spindle.
https://uploads.tapatalk-cdn.com/201...10b9c4cde0.jpghttps://uploads.tapatalk-cdn.com/201...69e14ba523.jpg
That was the inner bearing and seal.
https://uploads.tapatalk-cdn.com/201...39cac91325.jpg
That’s the “washer” for the spindle nut. Looks like it got chewed up pretty bad.

And here is the outer race.
https://uploads.tapatalk-cdn.com/201...e83d2fa851.jpg

The inside of the hub looks good where the races seat so that’s positive. I didn’t expect damage there but you never know.


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