Front bushes on rear trailing arms.........is it possible to change them without removing the arm from the vehicle?

this is a press in bushing so removal of the arm is required to change it. if you want to save time you can usually buy the part new it will have the bushings installed

You can. I remove the bolt and insert a block of wood between the arm and the body to help keep the arm lower and then press the bushing in and out

Lift Vehicle and place on axle stands. Remove wheels. Disconnect the lower control arm from the bolts that hold the ball joint, or from the knuckle. Undo the rear two bolts that hold the ''D'' shaped rear bush and the bolt that holds the forward bush. Have it pressed out and replace with new one. Reverse the procedure for installation. While the arm is out check the condition of the ball joints and replace if needed. After assembly have the front wheel alignment checked.

I am assuming you are talking about the lower control arm rear bushing which is common to these vehicles. The arm must be removed. the bushing is pressed in and out of the arm but a hammer and some other tools can be used instead of a press. the key is finding a socket or pipe that fits over rubber of bushing catching the metal sleeve to drive the bushing in place. trying to install bushing by hitting on rubber without pipe or socket will never work. also some parts stores rent or lend tools a ball joint press works well.

check the shocks, stabilizer bar links and bushings,trailing arm and lower control arm bushings and looseness in the rear wheel bearings.

opper Control Arm Bushings

• To access the upper control arm, remove the shock absorber and the strut bar. Also, disconnect the sway bar from the lower control arm, if your particular Ram model is equipped with it. After that, you can hold the coil spring in place with a spring compressor.
  Secure the wheel hub assembly to the chassis using a wire before you disconnect the upper ball joint. This will prevent damage to the brake hose. When ready, release the ball joint using a ball-stud loosening tool (see Resources).
  The upper control arm mounts to the chassis with a cam bolt assembly. Once removed, you can place the control arm on a vise and remove the bushings using a bushing service tool (see Resources). When installing the new bushings, do not use any lubricant but make sure the flange on the bushing end seats properly on the arm bore. Then re-install the upper control arm. When finished, take your Dodge vehicle to a good shop to align the front suspension.
  

Lower Control Arm Bushings

• Remove the shock absorber and strut bar. If your particular model is equipped with a sway bar, disconnect it from the lower control arm.
  Secure the coil spring with a spring compressor and release the lower ball joint from the wheel/hub assembly using a ball stud loosening tool (see Resources).
  Now you can release the lower control arm by removing the rear mounting bolts. Remove the bushings with a bushing service tool (see Resources). When installing the new bushings, do not use lubricant and make sure they seat properly on the control arm bore. Then replace the lower control arm. When finished, take your Dodge vehicle to a good shop to align the front suspension
  

You are on the right track, you can buy those bushings. Just go in and ask for the rear control arm bushings and they should be able to look it up and get the right ones for you. I have a 91 Camry, great cars.

LOWER CONTROL ARM

REMOVAL
1) Raise and support vehicle. 3) Remove the steering knuckle.
Remove the bolts fastening the power steering cooler to the front suspension cradle crossmember reinforcement (Fig. 21). 5) Remove the lower control arm rear bushing retainer bolts located on each side of each lower control arm rear bushing. NOTE: The bolts fastening the cradle crossmember reinforcement are of three different thread sizes. Note the location of the various sizes.

6) Remove the bolts attaching the cradle crossmember reinforcement to the front suspension cradle crossmember (Fig. 22). Remove the 2 bolts fastening the reinforcement and rear of cradle crossmember to the body of the vehicle. Remove the reinforcement. 7) Remove the pivot bolt attaching the front bushing of the lower control arm to the front suspension cradle crossmember. 8) Remove the lower control arm.

UPPER CONTROL ARM:

Do not disassemble the upper arm. If the ball joint or bushings are faulty, or the upper arm is damaged, the entire upper arm must be replaced.

1. Raise and support the vehicle safely.
2. Remove the front wheels. Support the lower control arm assembly with a floor jack.
3. Separate the upper ball joint from the steering knuckle using a ball joint separator tool.
4. Remove the self-locking nuts from the upper arm anchor bolts. Remove the upper arm from the vehicle.

Do not disassemble the upper arm. If the ball joint or bushings are faulty, or the upper arm is damaged, the entire upper arm must be replaced.
To install:
Use new self-locking nuts when installing the upper arm and strut.

1. Install the upper control arm assembly into the strut tower.
2. Connect the upper ball joint.
3. Install the front wheels and lower the vehicle.
4. With all four of the vehicle's wheels on the ground, torque the upper control arm nuts to 47 ft. lbs. (65 Nm). Torque the castle nut to 32 ft. lbs. (44 Nm); then, only tighten it enough to install a new cotter pin.
5. Tighten the wheel nuts to 80 ft. lbs. (110 Nm).
6. Check and adjust the vehicle's front end alignment.

The bushings on the front lower control arms are replaceable on most models.
This procedure requires the use of a press and may be above the skill range of the average driveway enthusiast. It is recommended that this procedure be done by a qualified machine shop if you are not skilled in the proper use of a press.

1. Remove the lower control arm that is in need of new bushings.
   

It is recommended that both the left and right lower control arm bushings be replaced at the same time. The vehicles handling may become unstable if there are new bushings on one side of the car and worn ones on the other.

1. Set up the control arm in a press.
2. Using a impact socket of the correct length and size, press out the old bushing.
3. Install the new bushing by slowly using the press to push it into the control arm.
4. WARNINGExcessive force could cause the bushing to bend or tear so be careful.
5. Once the bushing is properly seated in the control arm, remove the arm from the press and install it on the vehicle.

Im 100% positive that your problem is caused by worn out trailing arm bushings.