Coleman HS400UTV-2 Owner's Manual page 163

Shock absorbers become
5
spongy
Front and/or rear
6
differential is making noise
Periodic Maintenance and Adjustment
if the rear wheel axles are bent.
Check if tires are worn or deformed.
Check if overloaded.
Check if springs have excessive wear.
Check if shock absorbers have lost damping force.
Check if the spline of intermediate driving shaft is broken.
Check if the splines in left & right drive shafts of front & rear
differentials are broken.
Check if the gears in rear bridge reduction gear box and
differential are over worn.
Check dust covers of constant velocity universal joints in right
& left drive shafts.
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