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 movein 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 the clue!
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 thetransmission 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 backhome, 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 Jeep Wrangler 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.
Follow along as we guide you step by step through the installation:
Be 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.
Underneath 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.
Remove the six large bolts holding the skid plateto 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 androll it out from underneath the Jeep.
Here 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!
With 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!
The tranny mount is attached to the transmission by four more bolts. Simply remove them and catch the mount as it falls loose.
Here 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.
Finishing 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 the jack!