Engine and Transmission Mounts: The Jeep Wrangler’s Unsung Hero

Stock drivetrain mounts in a Wrangler consist of metal and rubber. The motor mounts are located on either side of the engine to anchor it to the factory K-member.

The transmission mount is located on the tail shaft of the transmission and secures it to the transmission cross member. The rubber in the mounts works to reduce noise and vibration that would otherwise shake the entire vehicle to no end.

Bad Jeep engine and transmission mounts seem like the end of the world. It is something that should be taken seriously enough to stop driving the vehicle until they are replaced but the fix is simple.

A number of things can cause mounts to go bad. The rubber within can dry up or the steel can rot. And of course, hard use will result in the destruction of these mounts. Vibration and irritating sounds coming from these components are just a few signs of bad drivetrain mounts.

Jeep builders aren’t solely limited to the factory style engine and trans mounts. For each build custom mounts are available. In many applications, factory type mounts will suffice but at a certain point a custom set of mounts may need to be considered. The types of mounts on the market will each have distinctive characteristics that may or may not be desirable and you will need to be aware of this while shopping.

Solid Mounts: Most engine mounts will use some sort of rubberized bushing to eliminate vibration and noise. Solid mounts ditch the shock absorbers and solidly connect the drivetrain to the cross members.

This is sort of a taboo concept because it increases the feel between the driver and the car but can be very hard on mechanical parts. For a Jeep, you will want to avoid these types of mounts. The excess vibrations can shake plastics and screws loose and may also be extremely hard on the transmission.  

Polyurethane Mounts: Many aftermarket motor mounts will use polyurethane in place of the rubber that is used from the factory. The reason to use these types of bushings on engine and trans mounts is exactly the same as you would use them for suspension parts.

They are much more durable and will flex much less than rubber bushings would. In the case that you are beefing up the Jeep in any sort of way, you will want to consider the use of polyurethane drivetrain mounts.

Drivetrain Swap Mounts: In the case that you are looking to run a custom drivetrain, you will need to run custom engine mounts. If you are swapping an LS, third-gen Hemi, or any other combination of engine and transmission that isn’t stock to the Wrangler, the custom mounts will either need to be purchased or fabricated. Many aftermarket suppliers will produce these components but it is still a hurdle to be aware of.

Motor mounts aren’t always used to simply mount an engine in place. In some instances, they will have a lift on them to displace the engine from its original mounting location. As the body or suspension lifts, the geometry of the engine can become hindered causing vibrations and other potential issues. Lift mounts are used to cure these issues.

Why They’re Needed: As the body and suspension are lifted the driveline angle and motor’s mounting point in relation to the radiator and other points can be thrown off. Unpleasant vibrations are just the least of your worries at this point.

With lift mounts, you are correcting the engine’s position, which will keep the engine from facing mechanical issues, and keep you from dealing with shaking as you accelerate.

What drives most people away from installing motor mounts on their vehicle is the level of difficulty they are lead to believe it is. With an engine hoist and a jack on hand the job really is a simple one. The thing to be leery of is the fact that you are working in a tight area where hundreds of pounds is suspended. If done with caution and treated with respect you will not run into many issues.

Engine: To install aftermarket or replacement engine mounts the motor will need to be disconnected from the factory mounts. You will want to use a hoist to lift the engine to make this possible.

On Wranglers the mounts are held in place with a few nuts and bolts. Aftermarket mounts will simply bolt in place of the factory mounts. With lift mounts, you will want to pull the engine up high enough to make sure you compensate for the added height.

Transmission: The transmission mount is at the tail shaft of the transmission. With a floor jack or a transmission jack you will need to lift the transmission up after the mount is disconnected from the cross member so you can access the fasteners that hold it in place on the transmission. For this process the Jeep's driveshaft should be disconnected to keep you from binding up.