Corrosion Alert!

[navylife59]

Having dropped 2 k-members (Front Suspension Crossmember Sub-assembly
) and confirmation from a 3rd individual, there seems to be an unknown corrosion issue on the passenger side of the K-member mounting points. At the time of this posting, it is unknown if Toyota knows anything about this. If more people discover this issue with their tC's, go to the Dealership immediately and have it addressed. Corrosion is no small matter when it comes to bolts, especially suspension and steering ones.

I will add a poll and leave this topic open for discussion.

This diagram shows the location on the passenger side frame mounting stud/nut (marked in red) that has corroded threads. The driver side stud/nut has only normal corrosion.

This is the actual corrosion on the cross-member, lower side where the nut attached to the stud.

This is the actual corrosion on the cross-member, upper side where the stud runs through.

This is the actual corrosion on the rack-and-pinion mounts for the cross-member.

This is the culprit, the A/C condensation drain. It drains directly onto the cross-member, puddling ontop and inside.

A simple fix is to attach a 3/8 ~ 1/2" ID vacuum line to the same size 90° elbow; ziptie together.

Here is the completed mod. Easily done with the aid of ramps or a jack with safety jack stands. It directs the condensation droplets harmlessly down and rearward into the airflow under the car. It can be position to drop onto the s-pipe where it will dissipate quickly as steam.

[navylife59]

Upon inspection while doing work in the rear trunk pan and behind the bumper fascia, I discovered some corrosion prone areas. Some were from wear of of paint surfaces via two parts rubbing against each other (fretting corrosion). Others were caused by water intrusion in seams (failed seam sealer) and puddling under the lower segment of the trunk gasket where there was only the electroplated primer.


Layout of corrosion prone areas.


Example of corrosion from a failed seam seal. This can be more difficult to repair as the corrosion may go in between metal joints and fillets. Seam sealer will have to be removed to gain access to affected areas.


Example of water intrusion caused by water puddling (low point) underneath the trunk gasket. This may be due to use of pressure washing in the joint of the hatch door forcing water under the gasket, at which point, it travels downward to the low point. Suggest careful use of pressure washing this area and to do monthly checks underneath the lower section of the trunk gasket.


These three areas are examples of Fretting corrosion caused by the rear bumper fascia (cover) wearing away the paint and primer surfaces. Depending on how much access that water has to these areas determines the amount and severity of the corrosion on the now unprotected metal. Find and treat the corrosion in these areas. This can be down by removal or encapsulating of the rust, then painting to seal. Once this is cured, apply a medium bead of silicon onto those areas and others that may be prone. Allow the silicon to cure somewhat, but not hardened (fully cured), then reattach the rear bumper fascia,