Resistance not adjusting

Adjust the Hydraulic Tension
Locate the hydraulic adjustment pins. These pins are movable and can be positioned in four holes on the Gazelle to adjust the tension. Find them on each side of the machine where the handlebar meets the foot peddle. Pull the clip from the hydraulic pin.
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Hi There, does this machine adjust resistance with a turn knob or via electronic buttons? If it's a crank or turn style resistance adjustment, this is usually positioning a pair of magnets near a spinning disk inside that front cover. Electrical "magnetic" resistance units use an Eddy-Current brake system which also produces a magnetic field near the spinning disk, either way the magnetic attraction properties will stop any metal (conductive) disk from spinning, or at least provide a resistance to it spinning ;o) Crank tension units have a cable and pulley system inside. Good Luck

try ignoring the factor default tension setting and try the simple method of pulling the thread through the tension plates
just before threading the needle, pull on the thread and there should be a resistance to pulling the thread
now adjust the tension up or down to get the two threads to meet at the center of the materials

I assume you have tried adjusting the top thread tension and are referring to bobbin tension adjustment. Before you do anything, with the bobbin properly threaded, manually pull out some bobbin thread. There should be resistance, just like the resistance you feel when you pull on the top thread with the foot down. Bobbin tension adjustment is by means of a small screw in the bobbin assembly. Mark the screw head position before you start adjusting it (so you can return to that position should you need to). Make small adjustments (1/8 turn of the screw) in each direction and see if it helps the problem. Be aware that thread tension is only one of many problems that can result in faulty stitches.

This happened to me and I took the wheel mechanism cover off to discover the tension motor cable had come out of it's pulley guide- so there wasn't enough tension left in the cable to pull it away from the wheel- quite an easy fix for me- hope it is the snake for you!

Bunching of thread is 99% a top tension problem. Make sure you thread the top thread correctly. Thread the machine with the presser lever up. Test the tension by lowering the presser lever before threading the eye of the needle, by pulling the thread with your left hand and adjusting the tension with your right hand while slowly pulling downwards. There should be no resistance when the tension dial is on zero, and you should be able to feel more resistance when you increase the tension. Ideal tension is between 3 and 5. When your top tension is correct, your machine should operate correctly. If you feel no resistance with the presser foot down and the tension dial on 5, check the tension disks for fluff or broken thread. When you lift the presser foot, the tension disks should open and you would be able to remove any cotton or fluff. Good Luck

ADJUSTING THE RESISTANCE When the resistance setting changes, the motor will be heard. To prevent damage to the motor, do not pull any of the cables while the resistance setting is changing. If a cable is pulled, the words RELEASE HANDLES AND READJUST RESISTANCE AS DESIRED may appear in the main display on the console.If this message is displayed repeatedly but no cable is being pulled, there may be too much tension on the Upper Cable . Adjust the tension as described below. To decrease the tension on the Upper Cable.turn the two 3/8” x 38mm Tension Screws twice,counterclockwise. Select the desired resistance setting.Repeat this step if necessary.CLEANING THE BAR GUIDES Over time, dust may build up on the Crossbar Guides , causing a squeaking noise as the resistance system is used. If this occurs, wipe off the Crossbar Guides with a damp cloth and a mild, non-abrasive detergent. Do not use solvents.
RECALIBRATING THE CONSOLE To recalibrate the Console , first plug in the resistance system . Plug the indicated end of the Transformer into the Back Mech Cover . Plug the other end of the Transformer into a 120-volt outlet. All indicators and displays on the console will flash once; the console will then be ready for use. The motor may be heard while the resistance system calibrates itself. Important: Always plug in the transformerwhen using the resistance system., press and hold the NEXT button and the MOTORIZED WEIGHT ADJUSTMENT + button for five seconds. When the buttons are released, a number will appear in the REPS display. Press the NEXT button again, then press the MOTORIZED WEIGHT ADJUSTMENT + button; this will start the recalibration process. This may take a few minutes as the motor moves between the lowest and highest resistance settings. When the motor finishes, unplug the transformer from the 120- volt outlet.The Console will be recalibrated. Use the resistance system as described in the CONSOLE

When the resistance setting changes, the motor will be heard. To prevent damage to the motor, do not pull any of the cables while the resistance setting is changing. If the motor has difficulty adjusting the resistance level and no cable is being pulled, there may be too much tension on the Upper Cable (110). Adjust the tension as described below. To decrease the tension on the Upper Cable (110), turn the two 3/8” x 38mm Tension Screws (106) twice, counterclockwise. Select the desired resistance setting. Repeat this step if necessary.

If you can hear the adjustment motor running the problem could be related to two things:
1. Broken or stretched resistance adjustment cable.
2. Broken bracket for the magnet return spring.
If the resistance is on maximum all the time the second issue is most likely the cause.

Check the tension disks. Sometimes a piece of cotton breaks off in between the disks and prevent the disks to tighten properly. When you pull the thread with your left hand and adjust the tension with your right hand you should be able to feel if there is any resistance. If no resistance can be felt, it certainly is a problem with the tension disks.