Suspention noise Honda Grace

[Randeewa]

I have Honda Grace 2016 car with 105000 genuine mileage. few months ago some noises started when hitting pot holes and when driving damaged roads. when checking with my mechanic he suggested a full suspension repair as all parts are original and already completed 100000 km. all worn parts replaced including 4 shock absorbers with shock mount and related parts, Complete steering rack, balance bar bushes, two links, lower arm bushes, caliper pins, after repair he confirmed there are no any worn out parts generate noises. Unfortunately there is still knocking noise when hitting pot holes. mechanic failed to find any reason he suggest replace both front CV axles as there is play on inner CV joints.( He says bearing or CV cup worn out)

1. Is there knocking noise generate when hitting pot holes if inner joint worn out?

2  is this is a common issues for this particular car model and where would be the cause?

Any one has a idea i highly appreciated    

[Hyaenidae]

Ran the query through GPT just for fun 😬

Below is what usually happens on a 2013-2020 “GM6” platform Honda City/Grace and how it fits your symptoms.

----------------------------------------------------
1. Can a worn inner CV joint make a knock when you hit a pothole?
----------------------------------------------------

• Inner (in-board) CV joints typically knock or clunk when torque reverses – for example the moment you get on/off the throttle or shift from Drive to Reverse.  

• They are almost silent on pure vertical impact loads such as a pothole hit; the joint is not changing angle and the tripod rollers stay centred.  

• A bad INNER joint therefore **rarely produces a “pothole knock.”**  

• An OUTER joint can “rattle” on bumps if the cage is badly worn, but it is accompanied by the classic metallic clicking on tight turns – which you have not reported. 

 
Conclusion: replacing axles is unlikely to solve a noise heard only when the wheel travels up/down over road damage.

----------------------------------------------------
2. What is common on the 2016 Grace and where else to look?
----------------------------------------------------

After 100 000 km the parts you already renewed are indeed the usual culprits, but this platform still has a few spots that mechanics overlook:

 

1. Strut top nut or bearing plate  

   – The new struts come with an M14 shaft nut that must be run down with an impact gun *after* the car is sitting on its wheels. If that nut is even ¼ turn loose, the shaft jumps inside the mount every time the wheel drops, making a single “tok”.  

 

2. Upper spring isolator (rubber seat)  

   – Re-used isolators compress and the spring can re-index in the pocket when the strut extends suddenly. You feel it as a sharp knock through the floor pan.

 

3. Stabiliser (sway-bar) D-bush brackets on the sub-frame  

   – New polyurethane or “555” aftermarket bushes are slightly narrower than OEM. The brackets bottom on the stops before they squeeze the bar, leaving clearance that only appears when the bar is unloaded (wheel in the air). Grease the bar, bolt up, then pry the bar up/down by hand; if it clicks, insert 0.5 mm shims or fit genuine bushes.

 

4. Steering rack mounting bolts / EPS rack guide adjuster  

   – The electric rack is isolated by two aluminium/composite bushes. If the through-bolts were not torqued to 64 N·m or the guide screw preload was not set, the rack shifts in the cradle over bumps and the sound travels up the column. Have someone kick a tyre while you watch the rack; any visible fore-and-aft movement is wrong.

 

5. Front sub-frame locating dowels  

   – During the suspension job the sub-frame may have been dropped. If the two taper dowels were not re-aligned, the sub-frame can “pop” against the body on sharp impacts. Loosen the four main bolts, jiggle the frame, then torque to spec (74 N·m) starting with the rear pair.

 

6. Brake pad or caliper bracket play  

   – New slide pins won’t cure a knock if the pad backing plates are slightly undersize. Fit anti-rattle shims or new OEM pads.

 

7. Engine mount (torque rod)  

   – The small horizontal mount at the rear of the engine lets the power-train rock into the firewall on rebound. Its failure is common on hybrid Grace/City because Auto-Stop starts the engine every few seconds. Look for cracked rubber or shiny witness marks on the bracket.

 

Is it “common”?

  
Owners on Thai, Indian and Sri-Lankan forums report exactly this “one sharp knock on potholes” at 70–120 k km; the fixes most often reported successful are:

• Retorquing the strut top nuts / replacing the top bearings.  
• Changing the sway-bar D-bushes with genuine parts.  
• Packing the steering rack guide or replacing the rear engine mount.

----------------------------------------------------
Practical next steps (no extra parts thrown):

1. With the wheels on the ground, put a socket on the strut shaft nut and give it 1/8 turn – if it moves, test-drive.  

2. Pry the sway-bar up/down at the D-bush; if it clicks, shim or replace bushes.  

3. Have a helper kick the left wheel while you look at the rack; retorque mount bolts.  

4. Jack one wheel, grab the drive shaft near the inner joint and shake up/down – a bad inner joint will “thunk” even without rotation. If it is quiet, the CVs are innocent.

 

Only if step 4 clearly shows play should you spend money on new axles.

Edited June 24 by Hyaenidae

[Dee Jay]

2 hours ago, Randeewa said:

all worn parts replaced including 4 shock absorbers with shock mount and related parts, Complete steering rack, balance bar bushes, two links, lower arm bushes, caliper pins, after repair he confirmed there are no any worn out parts generate noises.

Did you replace all these with genuine brand new parts? How much did it cost? 

[Randeewa]

5 hours ago, Hyaenidae said:

Ran the query through GPT just for fun 😬

Below is what usually happens on a 2013-2020 “GM6” platform Honda City/Grace and how it fits your symptoms.

----------------------------------------------------
1. Can a worn inner CV joint make a knock when you hit a pothole?
----------------------------------------------------

• Inner (in-board) CV joints typically knock or clunk when torque reverses – for example the moment you get on/off the throttle or shift from Drive to Reverse.  

• They are almost silent on pure vertical impact loads such as a pothole hit; the joint is not changing angle and the tripod rollers stay centred.  

• A bad INNER joint therefore **rarely produces a “pothole knock.”**  

• An OUTER joint can “rattle” on bumps if the cage is badly worn, but it is accompanied by the classic metallic clicking on tight turns – which you have not reported. 

 
Conclusion: replacing axles is unlikely to solve a noise heard only when the wheel travels up/down over road damage.

----------------------------------------------------
2. What is common on the 2016 Grace and where else to look?
----------------------------------------------------

After 100 000 km the parts you already renewed are indeed the usual culprits, but this platform still has a few spots that mechanics overlook:

 

1. Strut top nut or bearing plate  

   – The new struts come with an M14 shaft nut that must be run down with an impact gun *after* the car is sitting on its wheels. If that nut is even ¼ turn loose, the shaft jumps inside the mount every time the wheel drops, making a single “tok”.  

 

2. Upper spring isolator (rubber seat)  

   – Re-used isolators compress and the spring can re-index in the pocket when the strut extends suddenly. You feel it as a sharp knock through the floor pan.

 

3. Stabiliser (sway-bar) D-bush brackets on the sub-frame  

   – New polyurethane or “555” aftermarket bushes are slightly narrower than OEM. The brackets bottom on the stops before they squeeze the bar, leaving clearance that only appears when the bar is unloaded (wheel in the air). Grease the bar, bolt up, then pry the bar up/down by hand; if it clicks, insert 0.5 mm shims or fit genuine bushes.

 

4. Steering rack mounting bolts / EPS rack guide adjuster  

   – The electric rack is isolated by two aluminium/composite bushes. If the through-bolts were not torqued to 64 N·m or the guide screw preload was not set, the rack shifts in the cradle over bumps and the sound travels up the column. Have someone kick a tyre while you watch the rack; any visible fore-and-aft movement is wrong.

 

5. Front sub-frame locating dowels  

   – During the suspension job the sub-frame may have been dropped. If the two taper dowels were not re-aligned, the sub-frame can “pop” against the body on sharp impacts. Loosen the four main bolts, jiggle the frame, then torque to spec (74 N·m) starting with the rear pair.

 

6. Brake pad or caliper bracket play  

   – New slide pins won’t cure a knock if the pad backing plates are slightly undersize. Fit anti-rattle shims or new OEM pads.

 

7. Engine mount (torque rod)  

   – The small horizontal mount at the rear of the engine lets the power-train rock into the firewall on rebound. Its failure is common on hybrid Grace/City because Auto-Stop starts the engine every few seconds. Look for cracked rubber or shiny witness marks on the bracket.

 

Is it “common”?

  
Owners on Thai, Indian and Sri-Lankan forums report exactly this “one sharp knock on potholes” at 70–120 k km; the fixes most often reported successful are:

• Retorquing the strut top nuts / replacing the top bearings.  
• Changing the sway-bar D-bushes with genuine parts.  
• Packing the steering rack guide or replacing the rear engine mount.

----------------------------------------------------
Practical next steps (no extra parts thrown):

1. With the wheels on the ground, put a socket on the strut shaft nut and give it 1/8 turn – if it moves, test-drive.  

2. Pry the sway-bar up/down at the D-bush; if it clicks, shim or replace bushes.  

3. Have a helper kick the left wheel while you look at the rack; retorque mount bolts.  

4. Jack one wheel, grab the drive shaft near the inner joint and shake up/down – a bad inner joint will “thunk” even without rotation. If it is quiet, the CVs are innocent.

 

Only if step 4 clearly shows play should you spend money on new axles.

Thank you for details. I think there is lot to learn from your reply to my mechanic. Specially about CV Axle

[Randeewa]

5 hours ago, Dee Jay said:

Did you replace all these with genuine brand new parts? How much did it cost? 

Brand new Yes. Original not sure. All parts (shock mounts, Sway bar links, bushes shock bumper stoppers, lower arm bushes etc) came with Honda Sticker with Badge . but I am pretty sure not genuine. as per Hyaenidae's   reply this will be s issue for me. Shocks are genuine Honda from Tech motors 42000 front each ( I don't like KYB Stiffness) rear around 30. Steering rack Used. Rs.30,000 but i replaced rack end and tie rod with new Honda brand cost 20,000.00 all 4 parts (Also may be not genuine).

 

[iRage]

18 hours ago, Randeewa said:

Brand new Yes. Original not sure. All parts (shock mounts, Sway bar links, bushes shock bumper stoppers, lower arm bushes etc) came with Honda Sticker with Badge . but I am pretty sure not genuine. as per Hyaenidae's   reply this will be s issue for me. Shocks are genuine Honda from Tech motors 42000 front each ( I don't like KYB Stiffness) rear around 30. Steering rack Used. Rs.30,000 but i replaced rack end and tie rod with new Honda brand cost 20,000.00 all 4 parts (Also may be not genuine).

 

Just a silly question....are you sure the noise if from the suspension? You are absolutely certain that this noise can't be something like the exhaust banging on something and it only happens when there is some significant force jerking it. Asking because my dad's RAV4 developed a thud. Assumed it was the suspension, but it so happened that it was the rear diff (the metal mount of the bushing was hitting the crossbar of the mounting bolt.

[Quiet]

same happened to me with the Audi large banging noise when i hit small bumps, suddenly it dissapeared i checked the suspension system and agents said there are no issues, no one knows what happened