Hub Bearing Conundrum. To press or???

Hub Bearing Conundrum. To press or???

I have been doing the pad and rotor swap from hell on my daughters 2010 Mazda 3. I have to replace the hub bearing (sealed unit). I can install the bearing in the spindle with out an issue using the old bearing to hit against. The issue is the hub that goes through the bearing. I have installed many of these by just putting a impact socket on it and using a three pound sledge. However this worries me as it is putting a lot of shock loading on the bearings. I don't have a press. I could go get one from harbor freight but there is a space issue. I was actually thinking that I could cobble together a press with a floor jack and some chain. Probibly not a good idea.

So. Can you just hammer these things in or should I go to harbor freight and get a press.

I have before used a barbell weight and some c-clamps. It was sketchy, but I was in a jam and it worked.

Here's one vote for the HF press. There's other useful stuff you can do with it too.

If you do get the harbor freight press, do yourself a favor and use the coupon for the air over hydraulic Jack to go with it. I'm still kicking myself for not getting it sooner.

RevRico wrote: If you do get the harbor freight press, do yourself a favor and use the coupon for the air over hydraulic Jack to go with it. I'm still kicking myself for not getting it sooner.

More details????

I have Air!!!!

If you're looking for validation to buy a 20 ton H frame hydraulic press, go for it man, they're useful. Air over hydraulic is nice, but you can pull the handle out of the manual jack and work the pump really fast that way to position the unloaded ram. Personally I don't like the idea of them, you want to go slow and have feedback when running a press, especially if you're not very experienced with one, when stuff goes wrong with that kind of force on it stuff goes WRONG.

That said you're probably fine hammering on it, done right the only energy transfer through the rolling elements is the jerk of the they see from the assembly moving with each hammer strike, if you set it up with the bearing supported and hammer on the hub itself you can even eliminate that, remember that the inner races just barely touch. Throwing the hub in the freezer would also help reduce the force required.

Or you could set up a bigass bolt and nut though the hub to pull it into place, that's what those "hub tamer" tool kits that let you do it on car do. Which every flat rate mechanic in the country probably operates with their Nut Destroyer 3000® impact wrench, if you want to talk about shock loading.

dean1484 wrote:

RevRico wrote: If you do get the harbor freight press, do yourself a favor and use the coupon for the air over hydraulic Jack to go with it. I'm still kicking myself for not getting it sooner.

More details????

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There's a copy of the coupon, if you click on it, it will go full size, stupid mobile upload site. Yes, it's almost as much as the press. My harbor freight accepts coupons like this, it's also on the hft coupons app.

Maybe my jack just wasnt bled properly, but it took hundreds of pumps just to get to the material, let alone get through it. This uses air instead of manual pumping, making it not an annoying pita to work with.

Link to hf site

The problem is that when you hammer the center "hub" through the bearing that puts HUGE shock load on the actual bearings. The reason I am so concerned is that I did one and when done the bearing felt terrible (like a bad bearing) So I pulled it apart and the side of the bearing came off with the hub leaving the rest of the bearing in the what I would refer to as the spindle (cast iron pieces that the bearing goes into). Inside I found that the carrier piece that holds the ball bearing in place was broken and although I did not find any real issues with the races or the balls the fact that the carrier was broken leads me to believe that hammering it in caused the damage.

Yes I did put the bearing in the freezer when installing it in the spindle. I then let it all warm up (about two hours on black pavement in the sun) and I had the hub in teh freezer for 24 hours when i went to install it.

Put all this together and I am thinking that pressing it in will be less damaging even though I have hammered many of these things in over the years.

I used the old bearing on top of the new one and hit it to set the bearing in place. I then used a large socket on the hub to drive it in square. The only thing I can think of is that maybe I should support the inner race on the bottom of the bearing when I am driving the hub in to it that way the two half's would be supported and the shock load will not be transmitted to the bearings but instead through both half's of the inner races.

It might depend on the particular car. Since I own a VW, replacing wheel bearings is a common task. I have an OTC Hub-Tamer kit for the job (IIRC, H-F sells a cheaper version). It presses the bearing in/out of the carrier while on the car. With the VW, there isn't a lot of surface of the race to press against to get the bearing out, so you need a fairly specific tool to get good contact on the race. The Hub=Tamer does a good job, although it can be finicky to set up.

I did some of these ages ago at a jobber house using our press. You need a pretty decent sized press to have enough throat to get the hub through (ours was about 8"). Actual pressure isn't much. Personally, for this, I would not use an air-press. It would be too easy to force something when it isn't aligned correctly and not notice until it's too late.