D6-8u Track Carrier Roller Replacment

"Bushings" are the portion that the sprocket contacts They fit inside a recess inside each rail segment. You can not see the ends of the bushings unless they are pressed apart.
"Pins" are the portion that you see the ends of on each outside rail segment. The pins do not show as they go through the bushings.
When "turning" pins and bushings, you are trying to "turn" them 180 degrees, thus in effect returning them to a tighter fit. As they wear, distance between the links increases.
"Master Pins" fit differently than the other pins and are removeable - although sometimes with great effort - BIG HAMMERS, or even worse conditions GAS AXE. Newer systems and equipment have changed procedures and methods of "connection" track ends.

Generally speaking, you can feel the bushings with your fingers and tell pretty easily if they have been turned.

CTS

If you are lucky enough, you could find good used, complete with stands. It can be a pain to attempt rebuilding worn ones. If upgraded with adapters, you could go with the life time lubed ones as well. Let's see how worn yours are; sometimes a person will build them back up by welding them too. JM

Roller Replacement -
How much is this machine going to be used, hard work or shows only?
Condition of the rails, pins/bushings, idler, sprocket, as well as the rollers themselves will play heavily in the expense and availability of bottom rollers.
This is a subjective approach - one can replace or rebuild almost anything - just depends upon time and $$$

Here they are like i said they are shot. I Currently have two new roller assemblies (9H8916) however according to my parts book they are for serial numbers 8U10653-10970. They came with cat. As for use its going to more of hobby use light to moderate work on my in laws ranch. Maybe blading out some old roads and pileing trees and plowing snow in the winter. 

Thanks

Yes, looks like you succeeded in maximum use for one of them. I would inspect for alignment as well, make sure everything is running true, otherwise the replacements will see damage to the flanges as well. I am spoiled here, as there are plenty of D6 8U/9U parts tractors at my friends farm that I am allowed to gather from if need be.
If you don't mind, share your location and maybe someone can point you in the right direction for more parts or assistance. JM

Wash the rails, idler, sprocket with some water to wash the dirt, debris off - take pictures of those and share
Those rollers have seen way more than life expectancy!
Look closely at the Bushings in the rails ( as some call them - chains) are they worn through to the pins?
As JM said, consider alignment
Track adjustment will be an indication of wear too.

CTS