|Last week my father called
me and told me that we would be working on 2 Explorers this weekend, his
& mine. Apparently the rear brake shoes were too worn to pass
inspection, so he pulls off the drivers side drum only to find that all
the springs etc. were rusted (destroyed more like it). It's easy
to spot - the springs would literally crumble in your hand. Apparently
the axle seal leaked and the rest is history. No damage to the differential,
and a rebuild kit for the rear brakes solved that problem. Now for
the axle seal.
1) Pull off the differential cover and
let the fluid drain out into a catch pan (it's an 8.8" so at least it HAS
Basic Sockets, Ratchets, and Wrenches
Picks, drill, and other optional tools mentioned
New differential fluid
New axle seals ($2.00 @ NAPA)
2) If it's a traction lock 3.73 like
this one, pull the little pieces of traction lock clutches out of the bottom
of the case (no, no time to replace the clutch pack). The fill plug
has a magnet on it too as I recall.
3) Now for the fun part, that pinion
shaft has to come out to remove the axles... Unscrew the cross bolt
and discover that a 1/4" bolt in a differential does NOT work. If
yours isn't broken (yeah right), then skip to step 4, otherwise read on.
This is no ordinary bolt. It is a 1/4" bolt with (I believe) a 5/16
head that is 2"? long. It is only threaded for a half inch or so.
The fun part is getting the rest of it out. If the broken piece has
no threads on it, a magnet will probably work. If, however, It was
like this (and of course it will be), there are just enough threads to
keep it in there. Our particular bolt had a piece of thread about
45 degrees around it left on it. The first thing we did was run out
to the local NAPA store and buy out their screw extractors, and a small
telescoping magnet. While we were there, we looked through the racks
and found that special bolt. Interestingly enough it was listed as
a part for GM differentials, not Ford. We bought it anyhow, and sure
enough it was the right one. It also has a ton of red Loctite on
it. We then proceeded to spend countless hours playing with drill
bits and screw extractors. It is absolutely impossible to get a standard
drill and bit at the proper angle to drill into the center of that bolt.
I did manage to nick the corner of it, which greatly simplified things
later on. After the screw extractor idea fell through, we placed
a call to our local mechanic friend. He called back to explain our
HOW TO GET IT OUT :
We chose option #1. The mechanic explained
to us that this happens on roughly 80% of the vehicles coming into his
shop with these types of differentials. After spending another hour
or so, we were able to take a straight pick and uncrew the bolt a little
at a time by pushing on that hole (where i nicked it with the drill bit.).
It got to the very end, where it refused to come out. I managed to
pull it the rest of the way out with the small magnet we bought.
Option # 1) Run to Sears, NAPA, whatever
before they close and buy out their stock of picks. Try every pick
you can get your hands on to get the thing out.
Option # 2 (Somewhat dangerous) ) Take
your trusty arc welder, get the thinnest welding rod that you can find,
and get ready to fire it up. DISCONNECT YOUR BATTERY CABLES SO YOU
DON'T FRY THE COMPUTER. Hold the rod against the piece of bolt, and
quickly touch the ground to the explorer. If you did it the right
way, you should be able to unscrew the bolt with the welding rod.
If you messed up, start replacing differential parts now.
Option # 3) If NOTHING else works, take
a sledge hammer and the largest punch you have, and drive the pin out of
the carrier. NOTE that you will now need to buy a new carrier for
your 8.8. (If you do this, write a letter to Ford and thank them
for putting a 1/4" bolt in your differential...).
4) Remove the pinion shaft, it should
slide out easily now.
5) Push the axles towards the center
of the differential. They should move freely. I would recommend
replacing both axle seals to avoid repeating this process in the near future.
The C - clips should now be visible, so take a pair of needle-nosed pliars
and carefully remove them. These C - clips are VERY slippery, so
be careful not to drop them. As you are pulling them out, notice
the orientation of the tiny black O-ring on the C - clip groove.
If you need to, replace the C - clips.
6) Pull the axles out and wipe them
off, remembering which side is which. An axle puller shouldn't be
needed unless you have a serious problem in there.
7) Take your seal puller and insert
it into the hole in the seal. If you do not intend to replace the
bearing in there, make the seal puller contacts ONLY the Axle Seal, not
the bearing behind it. Slowly use the slide-hammer to remove the
8) Admire this seal. As I said,
ours were only $2.00 a piece, and managed to fry the breaks on one side,
cause countless hours of suffering (In my case at least).
9) Take your new seals and replace
them in each side. We used a leather mallet here so we would not
destroy the new seal, I suggest you do the same. In reality, you
should have something that is the proper diameter to push the new seal
in with. I suggest a large 3/4" drive socket. Of course I didn't
bring those with me, so we used the old seal to hammer the new one in.
10) If your axles are OK, carefully
replace them and push them all the way into the center.
11) Replace the C - clips, noting
the position of the rubber O-ring. Here it is handy to have another
person pushing the axles back and forth until you have unobstructed accesss
to the C -clip groove. It is also handy to have a partner here WHO
DOES NOT TURN THE AXLES. If you do this by mistake, you will spend
some time trying to "Get the damn side gears back into position," to quote
Paul Gagnon. He's right too, it's annoying. When you have to
turn the unit, do so buy turing the center section (yes, it's somewhat
painful to do).
12) Pull the axles outward, the C
-clips should stop axle travel at a certain point.
13) Replace the pinion shaft and
screw in your new bolt. Make sure it's the special aircraft grade
1000 titanium bolt that doesn't exist.
14) NOW you can turn your axles and
make sure everything moves as it should.
15) Apply the proper type of RTV
to your differential and replace the differential cover.
I hope this makes your job a lot easier
than ours was. I would almost rather have taken my box of match sticks
and set up a new ring and pinion... Sorry there are no pictures,
but if someone has any, feel free to add them and any other information
to this write-up.