Mazda BT 50 Front Suspension Issues Explained(+5 Tips)

In this brief article we are going to discuss the front suspension issues that occur in Mazda BT 50 and what causes these failures.

The Top 6 Most Common problems with Mazda BT 50 Suspension are:

  • Noisy and Bouncy Front Suspension
  • Front Knocking Noise
  • Front Clunk Noise
  • Noisy and Bouncy Rear Suspension
  • Squeaky rear suspension
  • Sagging Rear End

Mazda BT 50 Suspension

The Mazda BT 50 is a compact and mid-size pickup category produced since 2006 in Australia as a derivative of the Ford Range, also developed in Australia. 

A Mazda BT 50 second generation was based on the Ford Ranger T6 platform. The BT 50 is into its third generation presently from 2021.

The Mazda BT 50 1st Gen (2006–2011) had a Torsion bar spring instead of coil spring in the front suspension for the 4X4 variant and coil springs for the 2WD variant.

The Mazda BT 50 2nd Gen (Ford Ranger T6- based) Front suspension was a Double Wishbone Type with an Upper Control arm, a Lower Control arm and a Coilover Shock Absorber Strut with Anti Roll Bar.

The Ford Ranger rear suspension consists of a leaf spring with 2 stages. The last leaf is a helper spring that increases the rear suspension rate when the payload is increased. 

Noisy and Bouncy Front Suspension

  • Front end pops and squeaks over bad roads
  • The Front wheels feel extremely bouncy
  • Going fast over a rough patch it feels as if the front end is losing grip and floating
  • Handling feels vague with a lot of roll
  • Seen commonly in the 1st Gen BT 50 (2006–2011)

Troubleshooting Noisy and Bouncy Front Suspension

  • The noise could be due to either failed shock mounting bushes or failed shocks themselves or both.
  • Bounciness is related to weak damping due to a failed shock absorber. The shock absorbers are basically unable to dampen bounce.
  • With weak front damping, cornering ability of the vehicle is highly compromised and leads to excessive roll
  • To confirm this, you can do a bounce test.

Bounce Test:

  • At the front of the vehicle, at any one corner, apply your weight vertically downwards in such a way that the suspension starts to bounce at that particular corner. 
  • Push downwards continuously in an oscillating motion till you now, have caused maximum vertical movement of the corner.
  • Now leave the corner and watch how many times it bounces on its own. 
  • If it takes more than one oscillation to settle, then it is confirmed that the shock absorbers have gone weak.
  • The top mount is comprised of 2 donut-shaped rubber bushings tightened against 2 large Cup-washers.
  • The bottom mount is eye-type and is bolted at its axis through 2 bolts to the Lower control arm.

Pro-Tips:

  • When tightening the Shock bottom bolts, make sure that the vehicle is at its normal ride height.
  • If this bush is tightened at any other ride height, the Bush  always rests in a twisted condition at normal ride height and will result in a reduced Bush service life.

Front Knocking Noise

Symptom: 

  • Knocking noise when turning
  • Knocking when going over a rough road
  • The noise is higher during rainy weather and reduces when the weather is dry
  • Seen commonly in the 1st Gen BT 50 (2006–2011)
  • Handling is poor
  • Steering shake at high speeds

Troubleshooting Front Knocking Noise: Lower Control Arm

  • Front end knocking is most probably due to worn out bushings or ball joints
  • The weather-dependent  nature of the noise points to the fact that Ball-joints are getting corroded and probably even rusted. The rust reduces when it is not raining and therefore causes lesser noise.
  • The worn out bushings and ball-joints allow the suspension arms to move excessively and hit the chassis or nearby components
  • The worn out bushings and ball-joints also allow the wheel alignment to be out of spec when experiencing cornering loads. This causes the handling problems.
  • This can be inspected by using a pry bar to check movement at the bushing joints. If any joint moves freely then it could be that the bushing has failed
  • The lower control arm ball-joint is the lower pivot for the knuckle during steering and hence is the root cause for knocking noise in a majority of known cases.
  • The bushes are not serviceable and have to be procured along with the control arm since the press-fit cannot be done without a specialized hydraulic or pneumatic fixture.

Pro-Tips:

  • The 1st generation BT 50 suspension has a front Torsion bar that runs through the control arm.
  • Be sure to mark the axial position of the Torsion bar using a paint marker

Troubleshooting Front Knocking Noise: Upper Control Arm

  • Steering wheel shake is generally associated with Upper control arm failure.
  • The knocking problem could be caused by the Upper ball joint and the upper control arm bushes as well, apart from other reasons.
  • The upper ball joint controls the Camber and when this joint has play, it also causes problems in the handling of the truck.

Front Clunk Noise

Symptom: 

  • Clunking noise from the front end when going over even small bumps on the road
  • Front Shocks and Tie Rods are in good condition

Troubleshooting Front Clunk Noise: Anti Roll Bar Mounting Bushes

  • You can do so by trying to shake the Anti Roll bar by hand and observing for noises near to the joints
  • The Chassis attachment bushing which holds the Anti-Roll bar(ARB) to the Chassis is a Cylindrical Rubber piece through which the ARB passes through. 
  • If this Bush wears out then it creates a clearance between the ARB and the Bush and allows the ARB to move around, causing noise.

Pro-Tips;

  • Apply Mounting Grease to the Bushing while mounting it onto the Anti roll bar.
  • You could also think of using a harder Polyurethane bushing from the aftermarket, which is harder and lasts longer

Troubleshooting Front Clunk Noise: Anti Roll Bar End-Links

  • The Anti Roll Bar End-links are anchored with sandwiched donut-shaped rubber bushings at the 2 ends
  • The donut bushings tend to fail over time
  • Once they fail, they allow movement of the end link and cause suspension ‘Clunking’ Noises

Noisy and Bouncy Rear Suspension

  • Rear end pops and squeaks over bad roads
  • The Rear wheels feel extremely bouncy
  • Going fast over a rough patch it feels as if the front end is losing grip and floating
  • Handling feels vague with a lot of roll
  • Seen commonly in the 1st Gen BT 50 (2006–2011)

Root Cause:

  • The Bounciness is due to the fact that there is insufficient damping in the rear suspension probably due to a failed shock absorber
  • The noise could be due to either 
    • shock mounting bushes or 
    • failed shocks themselves or 
    • both

Troubleshooting Noisy and Bouncy Rear Suspension: Shock absorber

  • Bounciness is related to weak damping due to a failed shock absorber. The shock absorbers are basically unable to dampen bounce.
  • With weak front damping, cornering ability of the vehicle is highly compromised and leads to excessive roll
  • To confirm this, you can do a bounce test.

Bounce Test:

  • At the front of the vehicle, at any one corner, apply your weight vertically downwards in such a way that the suspension starts to bounce at that particular corner. 
  • Push downwards continuously in an oscillating motion till you now, have caused maximum vertical movement of the corner.
  • Now leave the corner and watch how many times it bounces on its own. 
  • If it takes more than one oscillation to settle, then it is confirmed that the shock absorbers have gone weak.
  • The top and bottom mounts are eye-type with Rubber cushions and are bolted to the frame and axle bracket.
  • Along with shock absorber failure, the mounting bushes fail as well, causing knocking noises.

Pro-Tips:

  • When tightening the Shock bottom bolts, make sure that the vehicle is at its normal ride height.
  • If this bush is tightened at any other ride height, the Bush  always rests in a twisted condition at normal ride height and will result in a reduced Bush service life.

Squeaky Rear Suspension

  • Rear end squeaks during normal driving
  • Squeaking increases when the truck is unloaded as compared to when it is loaded

Root Causes:

The Squeak could be due to:

  • Interleaf friction
  • Failed front Hinge Bushing

Troubleshooting Squeaky Rear Suspension

  • The leaf spring pack works together to provide the required suspension stiffness
  • In this process, the leafs contact and cause friction and noise
  • The manufacturer provides rubber spacers to reduce noise, but these wear out over time
  • One solution would be to replace the rubber spacer pads
  • The other would be to regularly apply grease to the interleaf contact surfaces
  • Check also the condition of the leaf front hinge/hanger Rubber bushing. This consists of a steel bearing tube with 2 conical rubber bushings fitted around the tube

Pro-Tips:

  • If the bushing does not come out easily, you may need to use a Press-kit with an appropriate size collar
  • If the press-kit is not working, then you could you could use a torch and heat up the eye of the leaf spring just enough to melt the rubber and push it out
  • Make sure not to heat the metal of the leaf spring till Red-hot temperature, which could potentially damage the leaf spring
  • To fit new bushings, you could also create a Press-kit using a long bolt and some select Socket-heads that match your leaf spring eye dimension

Sagging Rear End

Symptom: 

  • The rear suspension sits at a lower height than normal without payload
  • On loading the rear suspension sags even further
  • One side sits lower than the other

Root Cause:

Ther rear end sag could be due to

  • Leaf pack would have reached the end of its life
  • Broken leaf within the pack on the side that sits lower
  • Broken leaf spring shackle on one side

Troubleshooting Sagging Rear End: Leaf spring

  • Inspect the leaf pack to check for any broken leaf within the pack. If so then you could replace the replace the broken leaf alone
  • A broken leaf  means that you have effectively lost the spring effect of one leaf and that the effective spring rate of the broken side has reduced. Due to the reduced rate, the side will sag more for the same load  on a broken leaf spring side compared to a good leaf spring side.
  • If there is no leaf breakage on either side of the suspension it would be a case of sagging due to fatigue; meaning the leafsping material has lost its basic “Springy” quality and needs to be replaced.

Troubleshooting Sagging Rear End: Shackle

  • Trucks that are used in the snow belt are susceptible to salt from the road and corrode faster than trucks that are not exposed to salty conditions.
  • The shackle, when rusted beyond a certain point, tends to break and sometimes even fall off the truck.
  • The leaf spring shackle holds the rear end of the leaf spring at a certain distance from the chassis. Once this is broken, the leaf spring sits on the chassis itself and therefore the chassis height on that side gets reduced.

Conclusion

In this brief article we have discussed the suspension issues that occur in Mazda BT 50 and what causes these failures.

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