richelieu

Hello,
I hope you're doing fine.

I have a issue (new one) with RX450h 2012 year after replaced rear shocks (by OEM ones). Let me share with you the context first:
- replaced both rear shocks - old OEM number 48531-48161 with new ones with OEM PN 48531-48164
- also replaced both rear link stabilizer by OEM ones also
- right now after replacing the shocks + stabilizer link new loud sound arised

The detail description:
- it doesn't matter if driving down the street traight or over some bumps or holes on the street but the sound is something like gun bangs
- sound is really loud
- the rear suspension calibration using Techstream doesn't help
- it happens randomly but if I drove the streets with holes or slowing bumps it happen more often
- even when starting the car in the morning and drive a few meters it bangs
- air compressor is starting 1-2 times a day
- no error code in Techstream

Do you have any idea what to check and analyze?

Thank you
marek

afpj

First, were the bolts torqued to spec? Also, was the final torque value attained while suspension was loaded?

richelieu

Well, thanks for answer.

Yes, all bolts torqued according to factory specs (shocks 90Nm), links bottom bracket 45 Nm.

The shocks were torqued by hand first, than put car down and torque to 90Nm finally.

Thank you.
Marek

afpj

Since the noise started after replacing the parts, double check the work. It sounds like you have a non-US spec vehicle. I'm not sure what part of suspension is adjustable via techstream and air ride is very rare in the US. Did something get unplugged and not plug back in? Perhaps some non-US RX450H owners might chime in on this. Can you reproduce the sound if you push up and down on the rear of the vehicle, AKA the old fashioned shock test?

salimshah

Just a nit ... do you mean loosely fit? ie left enough room to wiggle and resettle. Bouncing once or twice before torquing the bolts down is proper way. Failing to do that means the pivots will be stressed in loaded condition, leading to premature wear.

Once torqued [normal or abnormal condition], the banging is altogether a different issue. Most likely some component is loose ... could even in parking brake system, or totally unrelated thing like the spare not anchored or a loose item in the hatch or various cavities in the hatch like battery not held down etc.

Salim

richelieu

Let me answer to both:

@afpj :
- yes, the car is located in Europe
- the Techstream is not needed for any procedure in case rear shocks are replaced but can be used for car high level adjust measure and settings
- during replacing procedure I didn't disconnect any component related to AIR strut (there are both AIR strut and regular shock on rear side)
- old fashioned test doesn't provide such bangs -> expected behavior
- double check the work -> yes probable I have to => following to @salimshah

@salimshah :
- according to part numbers the shock lenght is correct one - lenght and width of the shock
- "enough room to wiggle and resettle" -> I do believe when shock put on place and fit by hand using bolt on the bottom and also on upper part => when both bolts fit the shock stands on position and waiting for nut on bottom and screw on top
- after put bottom nut by hand and screw uppoer bolt by hand I put the car down
- well, no bouncing once or multiple time before torquing => I have just put the car down and torque the upper bolt and bottom nut => this sounds like very good hint where to look at => so I will loose lift the car, put wheel off, loose bolt and nut than use jack to put lower arm a bit up to play with shock by hand... next put screw bolt and nut a bit by hand and put wheel back and put car on the ground => bounce the car multiple times and then loose upper bolt to 90Nm and lower nut to 90Nm
- does this procedure work? What do you think about?

- regarding parking brake => here I do not see any relationship to shock and stabilizer link = may be I am missing something
- regarding spare or any other components in the hatch - well I will double-check or better put it off the hatch + double check the battery

marek

salimshah

Repeating my statement:
Laden/unladen torquing sequence will not produce banging noise.

Banging nosie:
Something is loose and producing a rattle or noise. My intent was to open up your thought process to include visible and hidden things. Even a soda can rolling under the seat can produce the banging noise.

Evidence based diagnosis:
Depending on tools and facility you can jack up the rear and with a second jack under each end at a time lift the wheel. Just make sure the total weight is never picked by the jack under spring [Be careful].
You can take the vehicle to a suspension shop. They have lift and transfer weight and apply large leverage.

Salim

richelieu

Well. I have moved forward in this case...

Thank you @salimshah for ideas. I started over today with detailed study if workshop manual. I found out that I have installed the shocks in opposite way - there is a protector shield on bottom of the shock and it needs to be rotated in direction to the front of vehicle... I did it opposite. Nevertheless I have followed your advise to load vehicle on the ground and torque bolts and nut right after pumping rear part a bit. The bangs noice keep my angry mood.

But I have also start over with rear stabilizer links... And bingo, the left one wasn't torqued but only by hand when I installed it. So I double checked all bolts and torque them correctly.

Fingers crossed no bangs noice right now (after 20 km down the town.

I believe it could be a reason of the bangs.

Thank you for the support.
Marek