One thing that
every Jeeper will eventually need to replace on their trail rig
is their transmission mount. It's one of those unavoidable things
that just go with the territory when using (abusing?) our Jeeps.
How do you know
when your tranny mount has given way? Well, if it's really far gone,
you won't have a whole lot of wondering to do, especially if you
have a manual transmission. I discovered my shot mount on the Project
TJ one day at the top of a 4+ hill while leaning far over to the
side and desperately calling for a winch line. With the Jeep perched
nearly on its side, the entire driveline was able to shift over
to the driver side, allowing the manual shifter to get pinned against
the Tuffy center console. The weight of the transmission and Atlas
II transfer case was enough to make the shifters not want to move
in any direction. Once I was safe at the top of the hill and on
level ground, everything flopped back into place and was fine. There's
Once I got the
Jeep home I got out my floor jack and a block of wood. I put the
wood on top of the jack and placed it all underneath the engine's
oil pan. I slowly jacked it up until there was just a little pressure
under the oil pan and cranked slowly while watching over the transfer
case skid plate. Sure enough, the driveline went up and I could
plainly see that the transmission mount had come apart.
I took a quick
ride to the Jeep parts counter and picked up a new stock replacement
transmission mount and headed back home, sure that this was a do-it-yourself
job that I could easily handle in my driveway. For once, I was absolutely
correct in my assumption!
Swapping a transmission
mount on a TJ is a simple job that requires nothing more than a
floor jack, a block of wood if the jack isn't tall enough to reach,
and some simple hand tools.
I chose to go
with the Jeep mount for two reasons. First, it was immediately available
at the dealer. Second, though there are aftermarket companies making
polyurethane mounts, I have heard that some allow a noticeable difference
in driveline vibrations coming up into the tub of the Jeep, and
I already have more of my share of vibes to deal with.
as we guide you step by step through the installation:
sure you have your parking brake on and the Jeep in gear (if
manual) or in Park (if automatic). Also be sure to chock your
wheels in case the Jeep decides to move. Remember, safety first!
Also, be sure to wear safety glasses, as there will be plenty
of dirt and rust falling from the bottom of the Jeep as you
work under there. Place a block of wood on the jack. This not
only helps it reach the oil pan on lifted Jeeps but also will
spread out the pressure so you don't dent the pan. Lift the
jack until you just barely begin seeing the Jeep lift. This
is for driveline support only.
the transfer case skid plate, you will find 4 bolts. Note that
our skid plate has been modified slightly for an Atlas II transfer
case so your case may differ just a bit. Regardless, you will
have these 4 bolts. The bolts hold the tranny mount to the skid
plate. Remove the nuts on each one.
the six large bolts holding the skid plate to the frame of the
Jeep. Be prepared! As you remove these bolts, plenty of rust
and dirt will fall all over you. Protect your eyes! We recommend
loosening all six bolts almost all the way and then removing
them by hand the rest of the way out one by one. Remember, once
they are out, the skid will fall. Be ready, as it's very heavy!
Bend your knees up to help support it as it comes down. Slowly
ease it down onto your chest and roll it out from underneath
you can see the tranny mount while the skid plate is half-removed.
You can clearly see that the rubber bottom has come loose from
the main part of the mount. Yikes!
the skid plate dropped, you can plainly see how the tranny
mount gave up. The metal rod that goes between the tabs had
come loose when the tabs bent outward. Gonzo!
tranny mount is attached to the transmission by four more bolts.
Simply remove them and catch the mount as it falls loose.
you can see the old mount in two pieces (left) and the new mount
(right). This is a very typical failure for this mount and is
to be expected on any rig hitting the trails or high-mileage
rigs, in general.
the job is a piece of cake. Simply attach the new mount with
the 4 bolts then the skid plate, then the bolt the skid back
on to the frame just enough to hang it. The skid is the toughest
part. Lay it on your stomach and using your knees for support,
get it back up in place. If you have a gut, you can push with
that, too. Finally, with the skid still slightly loose but in
place, align the four mount holes and get the nuts on them.
Then tighten the skid up to the frame and follow up by tightening
the nuts down on the mount. You're done! Don't forget to remove