I need a little help. I grabbed a set of rear knuckles from a Miata at the pic-a-part today. One of the axles is very stuck in its hub. The axle is already toast, so I am not worried about it.
Things that have been tried so far:
1. Penetrating oil from from the big orange store
2. Smacking it with a small sledge
3. Going back to the big orange store for a Husky 4 ton 2 jaw puller/pusher. One by one breaking each bolt in the puller/pusher as is overloads and breaks a bolt (zing!). Eventually breaking a link in the puller/pusher putting an end to that fun. Husky tools a warranteed, so I have a new one now.
4. The yard put the axle/hub into a press (10,000 lb? but the counter guy really didn't know, I am guessing 12 ton min.) and pushed hard enough to mushroom the axle face even more and then slip, knocking a lug stud loose.
I now have it home. I also have a 12 ton press. Do I just put a load on it in the press and let penetrating oil keep soaking in and hope it eventually pops? Do I assume that all the efforts so far have trashed the bearing and go ahead and add heat? I do not have an air-hammer, so hydraulic press and 2 jaw puller/pusher are the currently available push tools. I plan on grinding the mushrooming down and putting a nut on it for better loading. Just to make absolutely sure, yes, the axle nut is removed 
Any advice from folks dealing with this before would be appreciated.
Thanks,
Matthew
Bearing is probably junk at this point.
I use a torch and ALL the shop press, with occasional taps from a deadblow. Replace the bearing after the axle is out. Add neverseize to the splines before reassembly
I've had good luck using a method similar to what Duster is describing, only with a puller instead of a shop press.
I've found that a pnuematic rivet gun (the ones for solid aircraft style rivets, NOT the pop rivet pullers) works really well for this. I haven't found an axle yet that hasn't yielded to this, but I also haven't tried it on something super rusty. My theory is that the sharp rapid, multiple times per second, hammering breaks the rust minutely but persistently. It usually only takes a couple of minutes or less.
On my E36 I was limited in tools so just kept swinging at it with a sledge hammer. It eventually let go. I can’t say I recommend that method. Preloading it in the press and applying heat seems like a pretty surefire way to pop it out. I’ve had good luck with impact type tools before as well.
Dusterbd13-michael said:
Bearing is probably junk at this point.
I use a torch and ALL the shop press, with occasional taps from a deadblow. Replace the bearing after the axle is out. Add neverseize to the splines before reassembly
I have the knuckle in the shop press, soaking in Kroil. I am sure I can put more pressure on it, but I wanted to check something first. The knuckle is currently resting on the three bosses (on on the upper bushing mount, two on the lower mount). Is this safe for the knuckle or should I support it differently?
When I was thinking of air hammer, I was not thinking of a rivet set hammer; I do have one of those. I gave a couple minutes with that, but I will try more in the morning. The whole thing is tight enough that the puddle of penetrating oil does not go down. It really oly looks like slight surface rust (not even 100% coverage on the hub), but I guess that is all that it takes with these. I am used to my Rabbit hubs which have more generous clearances evidently.
Thanks for everyone's help. We will see how it goes.
Matthew
I would change it so it is not resting on the bosses in the press.
I took one to a shop (after fighting it with hammer, puller, oil, heat, etc.) and they broke the top boss off in their press.
Good luck!
In reply to sevenracer :
Thanks for that. I will have to get more material to brace it up another way, but that is better than breaking the hub. I now have it under very light pressure.
Matthew
Do you know anyone with a decent air hammer you can borrow? That's what I wound up needing to use on mine.
Where are you located at? See if someone around you has some oxy to heat it up really warm, then when it contracts it should break the rusty bond.
I've had good luck with this style puller for removing stuck axles. Then again, I've also encountered one that was so stuck we wound up stripping the threads in the puller body with a 700 ft lb impact gun...
Nothing like the suspense of waiting for something to yield once you have All Of The Tons loaded up on a press. Heat, sprays, cussing and concussing. Beer helps. I've even resorted to really long jack handles and shrapnel shields. Eventually something will let go.
Good luck!
In reply to therieldeal :
I really want a puller like that. Do you have a particular brand that worked the best or anywhere to send me for one?
Thanks,
Matthew
Woo Hoo! A Measure of Success!
I do not have the axle fully out, but it jumped a whole bunch and jumped hard enough to pop the axle shaft out of the CV joint when it popped.
I now have to grind off the mushroom before I push through the hub. I tried the air hammer. The axle end was already mushroomed when I started, but I air-hammered long enough to put a crater in the end of the shaft; no dice.
I put the assembly back in the press with some parallels under the boss in the middle of the upper arm. I put significant pressure on it, but I can't say how much, since I did not measure my pull and I don't have the cylinder geometry to do the math. I then double-fisted MAPP gas torches. First I could see some glowing of the hub, then I could start to hear the metal heating. A little more heat, and then a hard pull on the press handle, and BANG! there it goes.
The hub has hammer deformation from the crew at the pull yard. I feel bummed on principle, but I really don't plan on using the old hubs anyway, so it is not really a big deal.
Thanks for everyones help. I still need a really stout puller like the picture above; that is really just too powerful and small to not have handy when at the pic-a-part.
Thanks for everyone's help and acknowledgement that the axles really can be that stuck and it wasn't just me screwing something up.
Matthew
matthewmcl said:
In reply to therieldeal :
I really want a puller like that. Do you have a particular brand that worked the best or anywhere to send me for one?
Thanks,
Matthew
I have rented this tool from Autozone before and had good luck with it, aside from the one time I didn't :). I agree, this thing plus a good cordless impact gun would be awesome to have while junkyard shopping.
https://www.autozone.com/loan-a-tools/loaner-axle-flange-puller/oem-front-wheel-drive-hub-puller/2050_0
therieldeal said:
I've had good luck with this style puller for removing stuck axles. Then again, I've also encountered one that was so stuck we wound up stripping the threads in the puller body with a 700 ft lb impact gun...
This is a common problem on Miatae. The press is just going to keep mushrooming the axle, and may bend the upright itself making it impossible to align the car properly. Ask me how I know.
I used a hub puller like this with a big slide hammer and the “towel method” (check YouTube). Got the puller and slide hammer on loan from NAPA. Heating the hub with a torch helps too. By now the bearing is probably shot, so good to replace the entire hub and bearing assembly.
ShinnyGroove said:
This is a common problem on Miatae. The press is just going to keep mushrooming the axle, and may bend the upright itself making it impossible to align the car properly. Ask me how I know.
Well E36 M3. That seemed to be a really good thing to check, so I pulled out the big calipers and the pressed upright is around .100 inches bigger between centerlines of the arm bolts. I checked a bunch of times, a bunch of different ways. So, bucks and hours down the drain. If this is so easy to do if you put it in a press, then I have to assume every eBay knuckle is also compromised. Good thing I am not in a hurry, but still annoying. Thanks for the tip; I am glad I checked.
Matthew
I got mine put together and off to the shop to do an alignment before I figured out that issue. Car was scooting sideways like a crab on the way there. I still had to pay for the alignment.
The 2nd time around, I just got the whole axle upright assembly from the junkyard so I was sure it hadn’t been messed up with the press.
