Diagnosing Broken Cherokee Motor Mounts
The Cherokee has 3 mounts; 2 upper and one lower:
Symptoms of a bad Cherokee motor mount:
DRIVER & PASSENGER side Mounts: For either the passenger or driver's motor mount the most reliable test is to visually look underneath the motor mount for signs of brownish streaks as shown in the photos. The mounts are filled with a hydraulic fluid to absorb vibrations and covered with rubber end caps. When the mount breaks the fluid comes out and leaks down the car leaving brown 'tears'. For example, on the driver's side, if a mount breaks, the fluid lands right on the end face of the transmission that's visible if you peel back the driver's wheel liner. If you ever see brown fluid leaks on that face, it's the driver's mount that's failed. With the passenger side look directly under the mount section that has the black rubber on it. Do you see fluid running down? (may be dried if it happened a while ago) If so, the mount needs to be replaced.
REAR Mount: To tell if it's the rear mount put the car on ramps where you can get under it. Then using your hands, try moving the motor front to back. If the mount is bad, you'll see the rear mount move back and forward. (the mount is located on the top side of the subframe underneath the car connected to a bracket at the back of the transmission. The mount but it has a rubber isolator on it and shouldn't move.)
Here is a link to a JCC thread with three different YouTube videos showing each mount, it’s location and being changed.
https://www.jeepcherokeeclub.com/threads/identifying-bad-motor-mount.250113/post-3034153 )
Also, see the photos below for examples of the brown "tears" that will appear underneath one of the two upper mounts when broken:
Fluid-filled motor mount with cracked/broken rubber isolator.
Brown fluid streaks (tears) down the motor mount onto the frame are telltale signs o the broken upper motor mount.
Brown tears - fluid streaks down the driver’s side of the transmission casing are always from a leaking driver’s side motor mount which is mounted directly above it.
The rear mount is a solid “pancake” style rubber bushing. Similar to the lower control arm bushings, these can deteriorate over time leaving the bushing separated from the mount. The engine/transmission will then have excessive play (often leading to the upper mounts eventually failing)
Unusual vibrations or movement can be difficult to diagnose. It can be something simple thigs like tires being out of balance to more complex items such as failed or failing suspension components. When diagnosing any unusual movement the motor mounts should always be considered a potential suspect. Occasionally the question comes up, "How can I tell if my motor mounts are bad?". Fortunately, on the Cherokee it's fairly easy to rule in or out a broken motor mount.
The Cherokee has 3 mounts; 2 upper and one lower:
- [Passenger upper] The passenger side mount connects the top of the engine to the body/frame underneath the coolant bottle.
- [Driver upper] The driver's side mount connects the top of the transmission to the body/frame underneath the battery tray area
- [Lower] The one lower mount is underneath the car connected to a bracket at the rear-underside of the transmission.
Symptoms of a bad Cherokee motor mount:
- [Drivability] One or more broken motor mounts leave a feeling of “motion” or vibration when driving, especially when accelerating or coming to a stop or when in a hard-lock turn, there can be noise or vibration as the engine/transmission combination moves/flexes loosely from the body.
- [Visual Movement] With the engine running, car in Park with the electric parking brake on for safety, open the hood and visually examine the engine. Does it appear to be rocking or shaking excessively?
- [Visual Indications] With the engine off and the car in Park, and parking brake on for safety, do a visual check:
DRIVER & PASSENGER side Mounts: For either the passenger or driver's motor mount the most reliable test is to visually look underneath the motor mount for signs of brownish streaks as shown in the photos. The mounts are filled with a hydraulic fluid to absorb vibrations and covered with rubber end caps. When the mount breaks the fluid comes out and leaks down the car leaving brown 'tears'. For example, on the driver's side, if a mount breaks, the fluid lands right on the end face of the transmission that's visible if you peel back the driver's wheel liner. If you ever see brown fluid leaks on that face, it's the driver's mount that's failed. With the passenger side look directly under the mount section that has the black rubber on it. Do you see fluid running down? (may be dried if it happened a while ago) If so, the mount needs to be replaced.
REAR Mount: To tell if it's the rear mount put the car on ramps where you can get under it. Then using your hands, try moving the motor front to back. If the mount is bad, you'll see the rear mount move back and forward. (the mount is located on the top side of the subframe underneath the car connected to a bracket at the back of the transmission. The mount but it has a rubber isolator on it and shouldn't move.)
Here is a link to a JCC thread with three different YouTube videos showing each mount, it’s location and being changed.
https://www.jeepcherokeeclub.com/threads/identifying-bad-motor-mount.250113/post-3034153 )
Also, see the photos below for examples of the brown "tears" that will appear underneath one of the two upper mounts when broken:
Fluid-filled motor mount with cracked/broken rubber isolator.
Brown fluid streaks (tears) down the motor mount onto the frame are telltale signs o the broken upper motor mount.
Brown tears - fluid streaks down the driver’s side of the transmission casing are always from a leaking driver’s side motor mount which is mounted directly above it.
The rear mount is a solid “pancake” style rubber bushing. Similar to the lower control arm bushings, these can deteriorate over time leaving the bushing separated from the mount. The engine/transmission will then have excessive play (often leading to the upper mounts eventually failing)