Judging from your description, the grease on the outer side was liquefied and discolored (dark brown), and the signs of fretting suggest that it was continuously subjected to high temperature and high load conditions.
Observations on the operating environment
Circuit driving with a FF car
Approximately 30 minutes x 24 runs
The outer side (drive wheel side) only had a tendency to liquefy.
These conditions are considered highly likely to exceed the usage limits (temperature and shear resistance) of grease intended for street driving of general vehicles.
In particular, the outer side is prone to large angle changes, high RPM, and impacts during driving, and is therefore prone to oil separation (bleeding) and oxidative deterioration due to temperature rise and shear force, which may have appeared as liquefaction and discoloration.
Bell Hammer Metal Grease Proposal
Bell Hammer Metal Grease has the following features and may be able to withstand severe operating environments such as this one:
Heat resistance: Maintains stable viscosity even at high temperatures.
Pressure resistance: Highly resistant to high load and high shear environments due to the extreme pressure additives.
Metal protection: Metal components inhibit abrasion of metal surfaces.
Recommended for racing and competition vehicles
In addition, users who are highly competitive have adopted the method of applying an appropriate amount of “Bell Hammer GOLD Spray” before use, and then using metal grease in combination.
The synergistic effect of the strong lubricating film forming ability of Bell Hammer GOLD and the heat resistance and extreme pressure performance of metal grease is believed to provide a more stable lubricating environment.
Please try this method if you like.
In actual use, we recommend periodic inspections to check for changes in condition.