For the life of me I don’t understand the thinking of US Auto makers, not putting a full set of grease fittings on ball joints.
What are they thinking?
The joints are now considered lubed and sealed for life. Some late 1970 and 1980 cars had removeable plugs to allow regreasing but there was no place for the excess grease to be expelled so the joint seal got expanded with each relube. Ultimately, the overfilled seal would split allowing contamination to enter and ending the life cycle of the joint. I opine that the US as well as foreign auto makers went to no lube joints as a way to lower the maintenence requirements of their vehicles, i.e. 7000 mile oil changes, no lube required joints, 60,000 mile tune ups, 100,000 timing belt changes, 50,000 mile tire life, etc. IMHO
That, and the costs associated with them. Best case, the housing can simply be punched at the time the housing is stamped and the insert will thread into it without any further machining. The CAPEX tooling costs are slightly higher for this added feature. Then there are the recurring costs associated with manufacturing of the plug, materials purchasing and inventory management, movement to the line and the labor to install them. There are at least 4 per vehicle. It may not seem like much but that’s some fertile PQP savings when you consider how many of these they make.
Not just US Auto makers. All or most car makers, Japanese, Europeans, even Chinese, have sealed-type ball joints & tie rod ends. While it’s a cost-cutting maintenance benefit for us, it’s revenue-producing for them auto makers & their dealers.
Even some of the new replacement ball joint manufacturers that offer ball joints for older vehicles no longer have grease zerts.
The sealed units should last well over 100k miles. My 98 pathfinder with over 300k miles is on the original ball-joints. If done correctly they can last for years. I know GM has had some MAJOR problems with their ball-joints since they started using the sealed systems. But after market companies like Moog made replacement parts with zerks.
Detroit noticed that a lot of people were not greasing their cars. They designed parts that would work a very long time without maintenance. Frankly I think it was a good idea on their part. Trying to grease the new joints damages them internally and will reduce their life unless they are already lube dry. It they are already dry a lube will extend their life, but not double it.
Basically the enemies of grease are heat and contamination. Ball joints don’t get hot so contamination is the only other thing to worry about. The old ball joints were not sealed so dirt and other contaminants got in. You had to pump in some new grease to flush out the old periodically, like every 2000 miles. The new ball joints are sealed so the grease stays fresh as long as the rubber seal is intact.
Now if only they would use a seal that would last longer than natural rubber.