[alfa] Rear wheel bearing replacement 101 (transaxle cars)

["Jeff Greenfield" <alfaguy@xxxxxxxxxxxx>]

David -

No I haven't written up the procedure before, but for your benefit and
others here you go. Please note that it has been awhile since I have done
one of these so I'm going from memory.

Without the essential tools, primarily the two or three special tools (more
on that in a moment), some assorted air tools (very large air impact wrench
for one), and oxy-acetylene torches this would be best left to a specialist
who has this stuff. Otherwise, if you are comfortable working on your alfa
and have (or have access to the proper tools) go for it. It is not rocket
science, nor does it involve calculus of any kind.

There are two different types of retainers used on the bearings. One was
used on the Alfettas, and the other on the later cars. You will need the
proper ring nut tool for your application, and a pair of replacement
retainers as they will most likely get destroyed during removal. The
retainers are interchangeable as long as you have the proper tool to install
the replacement. Lastly, I am pretty sure that the early retainers are NLA
anyway, so it is all kind of academic, other than the fact that if you have
an early car with the original retainers, you will need both ring nut
wrenches.

I strongly suggest putting the replacement bearings in the freezer the night
before. This will help them go in a little easier.

1) Remove cotter pin and loosen the nut that holds the stub axle to the hub,
access is through the hole in the middle of the wheel. This is very tight,
use a very large breaker bar or pipe.

2) Raise car, and support securely. All the usual safety disclaimers apply.

3) remove rear wheels

4) Unbolt half-shaft from stub axle. Be sure to clean the insides of the
allen head bolts with a pick and tap the key in ALL THE WAY. An air wrench
is usually needed to remove this easily. I think you will have enough room
if you wire the half-shaft up and out of the way, otherwise you might need
to remove it completely. Sorry can't recall for sure.

5) using a large BRASS punch, tap the stub axle out of the hub and bearing.
Leave the nut on the end of the shaft to protect the shaft. There are also
tools that can be used to do this, if you have something by all means use
it.

6) using a slide hammer, remove the hub from bearing. It will probably take
some effort but will come out.

Note: The order of the last two steps might be reversed, can't recall for
sure, but I think I have it right.

7) Most likely the outer race will be stuck to the hub. To remove, place a
large bearing separator on the assembly, heat the race until nice and warm,
and press the race off. You could also cut it off with a die grinder of some
sort, but be careful not to damage the shaft on the hub.

8) Now the fun really begins. First you need to remove the retainer, these
are torqued ungodly tight and staked in place. Add to this years of
corrosion (unless the last guy who replaced them was kind enough to use
anti-seize) and they are a PITA to remove. On a really good day, a 3/4" air
impact wrench with the air pressure cranked way up will be enough to remove
them.

On a not so good day, you will need to soak them in penetrating oil, heat
until glowing and then remove them.

On a really bad day, you will have to cut them out. It can be done without
damaging the threads by cutting in the groove that is provided for staking
them in place.

Also, remember that one side LH thread, and the other RH thread. This just
adds to the confusion.

9) You are now ready to remove the bearing(s). For this you will need either
the special Alfa tool, or a generic wheel bearing service kit of which there
are many on the market today. Assemble the tool in place, there is a slug
that fits the ID of the bearing that goes on the inside, the cup goes on the
outside and the pressure screw goes through the whole thing. Crank it down.

The bearing probably won't move. At this point, if the car has ABS remove
the sensor. Get out the oxy-acetylene torches again, this time with a very
large heating tip (you do have one of those right?) Start heating up the
housing. Move the torch in a large area to try to warm it somewhat
uniformly. Every so often crank the screw and/or hit the end of the screw
with a large hammer. Eventually it will start to move.

10) After everything cools down, clean up the inside of the housing and the
threads as best you can.

11) To install the new bearing, remove it from the freezer, and working
quickly, assemble it and the tool and use the tool to press it into the
housing. There is another slug that fits the OD (this is very important
otherwise you will damage the bearing, always press bearings in by the OD),
and either another or the cup (depending on what type of tool you are using)
that goes against the back of the housing, The screw goes through it all and
is used to draw it in.

12) Install retainer, torque to spec, and stake in place (like it is really
going to go anywhere?)

13) Use the threads on the stub axle to draw the stub axle into the hub, do
not tighten fully at this point.

13) reassemble everything else.

14) with the wheels back on and the car on the ground torque the center nut
to spec and install the cotter pin.

That's about it. With the right tools it is not that hard provided
everything comes apart as it is supposed to. It's when things are rusty and
corroded that it gets more difficult.

HTH,

Jeff -


-----Original Message-----
From: owner-alfa@domain.elided [mailto:owner-alfa@domain.elided] On Behalf Of
dmasters@domain.elided
Sent: Wednesday, December 15, 2004 12:46 AM
To: alfa-digest@domain.elided
Subject: [alfa] re: Rear axle noise on high(est) mileage GTV6

Jeff wrote in response to nardo:

> Replacement is not too difficult, provided you have the proper tools and
> things aren't too rusty. In the proper tools department, you need the
> special socket for the bearing retainers, a very large air impact wrench,
> and either the special alfa tool for removing/installing the bearings.
Also,
> oxy-acetylene torches will help greatly most times.

> Wheel bearings should be readily available from any of your favorite Alfa
> parts suppliers, or locally through any better parts stores that know
> European stuff. The bearings fit many other applications (VW/Audi/Saab,
> etc).

> You will also need replacement retainers.

Jeff, with the growl from the back of my Alfa75 getting ever louder, I have
searched the web for descriptions of how to change these rear wheel
bearings, and they all have the tone "don't try this at home!".  As someone
with a fair bit of Alfa mechanic'ing experience, this is disconcerting.

Have you ever written out a more detailed description that we can use?

The parts about special tools, and big this, and oxy that, are a bit more
than is usually required!
I need to know whether to make a booking at the dealer.  (Yes, we have
dealers!)

Thanks in advance.

Cheers,
david
---
1989 Alfa75 TS
2000 Alfa156 TS
Newcastle Australia
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