CV Axle
 

2001 Volvo S60 T5

The Question: If you were to remove the boot on a Volvo CV axle, what color should the grease be? If clean/clear, would it turn black over the years if the boot was properly attached?

Just got the vehicle back from Volvo dealer for 150K service and close inspection of right front inspection for possible bad tie rod. The very next day, the tire dealer showed me where the boot had come off, there was play in one of the silver metal parts of the axle due to a lack of grease, and what grease was there (and not thrown all over the surrounding parts) was black as coal.

Questioning how this could have been missed. One point of view out there is that the boot was probably off for awhile resulting in the grease getting all dirty and turning black. Thank you for the help.

the grease on the outside boot is gray/black color the inside boot is yellow.due to the miles on the vehicle it is most likely the boots leaked if there is no play it can be rebuilt.

Thank you. It was the outside boot that was visible with the black grease. What is involved in rebuilding it? I assume this is not something the volvo dealer would offer to do?

Constant-velocity joints (aka homokinetic or CV joints) allow a drive shaft to transmit power through a variable angle, at constant rotational speed, without an appreciable increase in friction or play. They are mainly used in front wheel drive and all wheel drive cars. Rear wheel drive cars with independent rear suspension typically use CV joints at the ends of the rear axle halfshafts, and increasingly use them on the propshafts. Audi Quattros use them for all four half-axles and on the front-to-rear driveshaft (propeller shaft) as well, for a total of ten CV joints.
Constant-velocity joints are protected by a rubber boot, a CV gaiter. Cracks and splits in the boot will allow the contaminates in, which would cause the joint to wear quickly.A CV joint is a collection of bearings and cages that allows for axle rotation and power delivery on a number of different angles and planes and for the axle to change length as it travels up and down. All the parts spin around in a protective layer of grease that is held inside the joint by a flexible, rubber boot. Without the boot, the grease would simply spin out of the CV joints. The boot also keeps dirt and grime out. On the CV axle are two CV joints along with one or two sets of splines. One side of the axle gets power from the engine, the other delivers the power to the driven wheel. Presto.