Simple
Maintenance: One of the
simplest things that is often overlooked on our trail rigs is differential
maintenance. When was the last time you swapped your diff
fluid and inspected your ring and pinion? For many of you
the answer may be "never." If "never" was your answer, consider that this can lead
to drastic problems if left unchecked - especially if you often wheel
in wet or muddy areas or if you spend a lot of time in rockier areas
where the diffs are working hard and absorbing the blunt of the
blows, either from the rocks (thru the tires and axles) or the drivetrain
itself (via your heavy right foot).
Perhaps you're the type that drives yours on a more frequent,
perhaps daily, basis and maybe you even have your oil changed at
one of those "quick lube" places where they change your
diff fluid by sucking the old fluid out, flushing the diffs (if
you're lucky) and then refilling them with clean fluid.
Regardless of the type of wheeler or driver that you or your
rig are, I would suggest pulling the cover every so often
(I pull mine about every 6000 miles - or about every 4 months,
whichever comes first) if for no other reason than to check
the ring and pinion and the torque settings on the bearings.
Checking your diff is a simple job and it can be done in your driveway with
a few normal tools in about 30 minutes.
Now, thanks
to our friends at LubeLocker, the entire job just got simpler and a lot cleaner.
These guys have used something very similar to head gasket technology
and placed it on a gasket for your differentials. They have taken
a thin sheet of steel and placed it between two layers of elastomer.
This "sandwich" creates a gasket that when properly
torqued down creates a seal between the diff cover and the mating
surface on the pumpkin without the use of any sealers or RTV.
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Cross Section of the LubeLocker (From the
LubeLocker website) |
Why does this make the job of changing your diffs easier then
ever? Follow along as I install a LubeLocker gasket
on the Dana 44 in the back of my Jeep.
The Dirty Deed: As you can see, my differential
gets a fair amount of abuse on the trails, which is one reason
I like to inspect it fairly often. On my rig, the diff sits
far enough below the gas tank that I can access all the bolts
without any issues, but, if it didn't I would need to jack up
the body slightly and let the suspension droop a little to get
easy access to the bolts.
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Dana 44 diff in a 1998 TJ |
Two bolts left in place |
After I loosened all the bolts on the diff cover, I removed all but
two up towards the top of the cover. Then I used a soft hammer to
tap on the diff cover to loosed it up on the RTV that was applied
during the last install. If the soft hammer doesn't work,
I resort to using a screwdriver and tapping it between the cover
and the housing.
Once the screwdriver is inserted, I can
twist it a little and this usually separates the seal the RTV
has on the cover. You may have to insert the screwdriver
in more then one place to completely break the seal. By leaving
the two screws in the cover it allows me to drain the diff in
a controlled manner into my catch pan without the whole cover coming off and the
fluid spewing everywhere.
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Using a persuader to remove cover |
Screw driver inserted to drain diff |
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RTV protruding thru the bolt holes |
Close-up of RTV |
Once I have drained the fluid I removed the last two cover
bolts and inspected what I had. To me, everything looked good
inside the diff so I could now put it back together... but first
I had to clean up all this excess RTV. If you look closely,
you can see the residue left by the RTV sealant on both the cover
and the diff mating surface.
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Diff mating surface. The
discoloration is RTV that must be cleaned up before reinstallation |
You need to clean the build up off the mating
surface and out of the bolt holes |
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RTV on the cover. All of this will need
to be cleaned |
Yuck! RTV residue being peeled off of the
cover |
Cleaning the RTV usually just requires a little patience. However,
it can be longest part of servicing your diff. I generally
use a razor blade to scrape the RTV off of the surface of the cover
and a small scraper to clean up the mating surface on the housing.
I also run my hand carefully over both surfaces to look for small
dings or scratches or places that I may need to file down or clean
up before I put the cover back on.
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Cleaned mating surface |
Bolts that will need to be cleaned |
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Inside of cleaned cover |
Cleaned up bolts |
Once I had everything cleaned up (including the bolts, because
I don't want to force RTV back into all of those holes), it was time
to lay another bead of RTV on the cover and - oh, wait, this is
where LubeLocker's new differential gasket comes in. Their
new gasket does not require any RTV or any other material outside
the gasket. Great!
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LubeLocker, and instruction sheet |