Help - front bearing install gone wrong

[tedder]

So I have read about a dozen threads about installing front bearings here on Pelican and I thought I could do it myself ... oops. Looks like I overestimated my abilities. I got the old bearing races out (heated hub up, inner came out easily, outer with much persuasion). Putting the new bearing races in has been the reverse. The outer went in fine, but the inner must be cockeyed or something as it is stuck about 3mm from seated.

But worse. I discovered that my efforts to pound it in a bit, have been, shall we say, a poor idea. I seem to have damaged the shoulder where the inner grease seal goes (see photo)



At this point, I am trying to figure out my options.

1. Is the damage to the shoulder fatal to the hub (!#@%!)
a) suck it up and order a new hub
2. if not, should I reheat it, drive the bearing races out again, and then
a) try to put them in again
b) get new bearings and try again
3. Take the hub to a mechanic (neither of my regular shops is open today) and see if it can be pushed in the rest of the way with a press.

I guess I am hoping that someone will tell me #3 is a good idea, but I suspect I may be looking at #1.

[FinallyGotOne]

Well that does not look good, but I would not say it is fatal. Though I cannot help out much as i am unsure of the differences between that hub and my 79 hub.

[Eagledriver]

I think the damage is on the bottom of the area where the seal goes. I think the seal goes on the very outer part of your picture (hold the seal up nest to the hub to confirm). I would take it to your local NAPA autoparts machine shop and ask them to press it in the rest of the way. You could also heat the hub to 250 or so and pound it the rest of the way in yourself. You don't need to have the race cool and the hub hot (although this helps). The hub expands more than the race with heat so you can pound it in. I built a tool for this by getting some big washers that were the same size as the race and mounting the washers on a big bolt that I could hit with a hammer.

-Andy

[tedder]

Andy & Finally,

thanks for the replies. The damage is to the shoulder that the seal presses in to and not to the surface where the bearing or the seal are. I think what happened is I caught my drift on the seal's shoulder instead of on the edge of the race.

I like the idea of the big washers and the bolt. I am definitely going to use this on the other side when I do that. Since this side was stuck when I put it in earlier (hot) I think I have the race a bit off straight now (I had used the old bearing race to start it fwiw and then a drift at 300 def hub and frozen race, lightly greased). So I think I''l try the machine shop to get it in the rest of the way on tuesday (or monday if I can find one that is open).

Sort of a nuisance to lose 2 days of planned work on the car though. After I got this in I planned to do valve adjustment but with the wheel off and only one pair of jack stands I am stuck until I resolve this.

Ted

[Jim Smolka]

If there is a local FLAPS, they may have a loan a tool program. The hot setup is a bearing press-in tool. Basically, a various since machined pieces of metal that mate up with the bearing race and it has a punch handle. Then just pick the right size and hammer away.

If that is not an option, then try grinding away ~1mm of the outside diameter of the old race. Use that as the pressin tool. The old race should not get stuck in the hub.

Other tricks in heating up the hub in the old BBQ grill and freezing the races.

I am in the phone book in Hickory NC

[tedder]

Before I got the race stuck it came out of the freezer and the hub came out of the oven (~305 degrees for ~20 minutes). I whacked with my bfh and yet I am stuck.

Fearing the $350 for a new hub would cause issues with my wife, I'm going to take the hub (and the other side which is now off as well) to a local machine shop as soon as I can fine one open tomorrow or tuesday and let them press the races in for me.

I had been thinking about removing a bit from the old race, but this is very hard steel and I have no idea how I would do that even semi accurately.

[tedder]

Update:

took it to my local honda mechanic (closer than the Porsche shop, and the son of the owner [30's-ish] has a 944) and then across the parking lot to a machine shop to have the races pressed in properly. They are both still about 2-3mm off of the shoulder with the cut-outs for the driver. The mechanic and machinist both stated that there is another shoulder there and that is as far in as it goes. So I may have had it in all the way all along. Before removing it there was enough grease in the bore I wouldn't have been able to tell.

On the other hand, should I take it by the local P-shop before install to be sure? Both hubs look like the races are in straight (to the eye) and the same depth.

Ahh, the perils of ignorance...

Ted

[DW SD]

Bearing races and hubs are not rocket science. I would tend to trust a machinist and good mechanic, whether or not they work on Porsches. Good luck!

Doug

[rusnak]

The hub is aluminum, the race is steel.

You should not pound directly on the race.

There is a special bearing race tool that is also made of aluminum that fits into the race. You pound on that tool using the supplied drift that comes with it. The tool distributes the force against the race without distorting it.

If you did pound on the race while causing damage to the hub, then the race(s) are probably shot. You can probably insert the bearing dry, spin it, and see if it hangs.

Anyway, I don't think your hub is unusable. The grease seal will probably work, as noted. It's an interference fit. As long as the hub is not distorted you're fine.

Use a torque wrench always to tighten your wheels, or you may distort the hub and it'll be trashed. Good luck!

[tedder]

The bearing spins in the race just fine with no sign of hang ups at this point. As for th damage, that was not from pounding the hub, but from the drift catching the edge of the oil-seal shoulder instead of the race. Race=hard steel. Shoulder=soft Al. Therefore shoulder damage.

Unfortunately I have to work late tonight and tomorrow so I won't have any chance to get the hubs on till thursday or friday at the earliest...

Next up:
- brake pads
- valve job

lets see how many times I call for help on those (forecast, 2+)

[tedder]

Final update:

bearings in, wheels on, new brake pads in place and I'm a happy camper. Since I bought it there has been some shake in the steering wheel at speed (sometimes). I had tightened the old bearings a couple of times and it didn't help so I figured it was the shocks. New bearings and the steering shake is gone. This should go into the 'Best upgrades foor under $200' thread if it isn't already.

[bkreigsr]

congratulations tedder.
I would still keep an eye on it for premature wear at your next brake service.

Bill K

[gigem75]

Gald you are back together, for future reference use can use Porsche tool 902.976.777 more commonly known as a 1 15/16 socket to put the race in, if you don't have a press. The size socket was just a guess, whatever size fits diameter of the race. You can clean up the buggers with your dremel tool. You should never try and install a bearing race with a drift, to many things can go wrong.

I'm assming you did not tighten up the spindle nut up all the way?

[rusnak]

Hey good job, glad everything worked out fine!

The bearing race tool that I use is made by Lisle Tool, and is commonly available at auto parts stores. It is made of aluminum, as I mentioned. I use a hydraulic press to finish the job, but mostly use the press tool to get it halfway there. The reason I don't simply heat the hub and press the race in by hand is that I want to be totally sure that the race is fully seated all the way, and is square to the hub. Anyways, there are lots of ways to skin a cat I'm sure.

If you want I can post pics of what worked for me.

[Zeke]

Originally Posted by tedder

Update:

took it to my local honda mechanic (closer than the Porsche shop, and the son of the owner [30's-ish] has a 944) and then across the parking lot to a machine shop to have the races pressed in properly. They are both still about 2-3mm off of the shoulder with the cut-outs for the driver. The mechanic and machinist both stated that there is another shoulder there and that is as far in as it goes. So I may have had it in all the way all along. Before removing it there was enough grease in the bore I wouldn't have been able to tell.

On the other hand, should I take it by the local P-shop before install to be sure? Both hubs look like the races are in straight (to the eye) and the same depth.

Ahh, the perils of ignorance...

Ted

I can't see from here, but I'm not 100% sure about that. Better check the adjustment sooner rather than later in case they move in a little more. If not, then you know the job was good. If they do move in, you will be saving your new bearings from a premature death. Always adjust bearings while spinning the tire slowly. I usually tighten until the resistance starts to feel, well, tight and then back off a 16th of a turn. YMMV.