No way you can inject any lubricant into them. The only thing you can do is replace them when they make noise when lack oflubrication.
Chassis is diffrent than transmission. Chassis lubrication is to lubricate bushings of all suspension and steering linkage. Nothing on wheels or gear box. Only one thing related to transmission was the famous car talk guys recomemnted to spray slicone spray on CV joint boots to reduce the rubbing wear between boot foldings
https://landrumlube.com/auto-oil-changes-blog/chassis-lubrication-what-it-is-and-why-you-need-it/
