If extraneous knocks appear in the suspension of a moving car, it is necessary to immediately establish their source, regardless of whether it is a constant knock or appears only when driving through bumps
It is better to check the condition of the suspension on a car installed on a flyover, inspection ditch or lift, and if this is not possible, you can do this work, albeit with less convenience, on a free flat area.
Begin the check by carefully inspecting the condition of the suspension parts.
- 1. Check the condition of the rubber-metal hinges of the suspension, the rubber bushings of the stabilizer bar and the reliability of fastening of their brackets.
- 2. Carefully inspect the suspension arms.
Cracks and mechanical damage to the levers are unacceptable.
- 3. Inspect the bushings of the upper and lower mountings of the front and rear shock absorbers.
Replace bushings with torn, cracked, or bulged rubber on one side.
It is quite difficult to diagnose the serviceability of a driveline by the noise it makes. If you are unable to pinpoint the source of the noise, contact a qualified technician.
Knock when starting off:
- - wear of the splines or joints of the cardan shaft, the fastening of the intermediate support to the bracket or the bracket to the body (on parts of cars) is loosened assembly, tighten the bearing mount);
- - the backlash in the engagement of the gears of the main gear is large, their teeth are worn out (adjust the side clearance in the engagement of the gears, replace the worn gears)
- - the gap in the engagement of the main gear gears is broken due to the unscrewing of the shank nut (if it was not cottered) (Tighten the nut to the recommended torque and cotter)
- - loose wheel bolts (Tighten bolts to recommended torque)
- - brake pads stuck or frozen to the drum (Do not use the parking brake when the car is parked for a long time, shift into gear)
- - detachment of the brake lining from the base of the pad (Replace the pad)
- - clutch (repair clutch)
- - lost elasticity or collapsed power unit supports (Replace supports)
Noise when driving on a flat highway:
- - bearings of the rear axle gearbox are worn, their preload is broken, the fit is loose (uniform noise from the rear axle) (Replace worn bearings, adjust the preload)
- - the teeth of the gears of the main gear are worn out, the lateral clearance in the engagement is broken, the scuffs on the teeth are a howl from the side of the rear axle, decreasing or disappearing when the load is reduced (releasing the “gas” pedal) (Replace the worn gears (pair), adjust side clearance)
- - fastening of the driven gear to the differential box has loosened (gear runout) (Tighten the threaded connections, thread sealant can be used), replace worn gears (in pairs)
- - wear of the bearings of the axle shafts or bearings of the front wheel hubs (Replace bearings)
- - the bearing of the intermediate support is worn out (on those vehicles where it is installed) (Replace the bearing)
- - cardan gear imbalance, output shaft runout or rear axle reduction flange (Replace worn parts)
- - tires are not designed for these conditions (all-terrain tires, studded tires, snow chains, etc. are used on asphalt) (Use tires according to their purpose)
- - high speed in turns (Slow down before turning)
- - uneven wear or tread peeling, deformation (Change tire wheel, rims)
- - the wheel touches the fender liner (especially on a loaded car) (Check and adjust the wheel alignment, replace sagging springs, deformed suspension parts). Do not overload the vehicle. Use only original rims
- - wheel bolts hit rear brake parts (Use bolts according to wheel thickness)
- - parts of the brake mechanisms touch the brake disc or drum (Disassemble the assembly, replace the defective parts)
- - the bolts of the wheel disc are loose (Tighten the bolts, if the wheel is deformed, replace it)
- - detachment of the brake pads from the base of the pad (Replace the pad)
- - howl whistle from roof rack (Slow down)
Knocks and squeaks when driving off-road:
- - The vehicle is overloaded (Do not overload the vehicle)
- - Defective shock absorbers, rubber pads (Replace the shock absorber or dismantle in the workshop, replace the rubber pads)
- - Destruction of the suspension buffer (Replace buffer/buffers)
- - Settlement or breakage of front suspension spring (Replace spring)
- - Settlement or breakage of the rear suspension spring (Replace the spring or leaf spring)
- - Anti-squeak pads between leaflets or rubber bushings worn or broken (Replace parts)
- - Worn or not lubricated rubber bushings in front suspension (Lubricate rubber bushings, replace worn ones)
- - Front suspension threaded bushings worn or broken (Replace bushings)
- - The front suspension kingpin is worn out (If the play cannot be removed by turning the kingpin by 90 °, then the kingpin must be changed)
- - Loose fastening of the front suspension beam to the side members (Tighten the beam connections to the side member)
- - The steering wheel is loosened to the steering column shaft (Tighten the threaded connections)
- - Knocking in the steering mechanism (Replace worn parts, adjust the gap in the engagement of the roller and worm, add oil)
- - Front suspension elements are bent (levers, rods, steering rods) (Straighten or replace deformed parts)
- - Loose fastening of the elements of the exhaust system (Tighten the muffler, etc.)
- - Loose fastening of the axle shaft (Tighten the threaded connections)
- - High tire pressure (Set normal pressure)