RX450h strut top mounts

[alanann]

This may be of interest to owners with air suspension.

Since buying the car in January I have a pitter patter knocking from the front suspension but also excess road noise

First thing I thought was tyre noise but the car had 4 recent new Bridgestone tyres so it seemed unlikely,

I read on the forum that the top mount bearings will be the cause and can be replaced at a reasonable cost 

I made arrangements to have the job done but when i got the mounts off the bearings were perfect so decided to give it a miss,

luckily it is a easy job to remove the mounts without needing to remove the wheels, 30 min job for an old codger with arthritis,

after a few months the noise was  driving me mad so i decided to remove the mounts again for another look and although the bearings were 

still ok I discovered another problem,

The mount has a 6mm gap for travel between the inner and outer parts of the mounting with a flange which acts as a stopper,

the problem is the rubber appears to have settled so when on the car with the weight on the wheels the gap has gone

and the flange is touching the main part of the mounting which is transmitting the road noise direct to the body and the when on rough tarmac the flange hitting the body mount is causing the knocking noise.

The answer is to prevent the 2 parts of the mount touching and transmitting the noise, see the pic

so as a test to prove the theory I use a length of 6mm nylon rope and wound it in the gap 2 turns and glued with hot glue to hold in place,

The result is amazing the car now drives as I expected when i got the car with no knocks and minimal road noise.

I plan on replacing the cord with a spacer from 6mm sheet rubber but for now the cord is absorbing the noise.

sorry for the long saga

Alan.

 

 

 

[Silversalmon]

Excellent, many thanks for sharing

[Barry14UK]

Thank you for posting.  Innovative idea to prove theory and idea of rubber spacer.  When fitted, might be worth marking position of top mount to check it is not moving about when job done.  

[alanann]

27 minutes ago, Barry14UK said:

Thank you for posting.  Innovative idea to prove theory and idea of rubber spacer.  When fitted, might be worth marking position of top mount to check it is not moving about when job done.  

Just to confirm the strut mounting is not altered, all the cord is doing is absorbing the up/down movement of the strut as the mount did originally before the rubber in the mount settled.