Yes in most cases Cat dealers do a good job.  However, when I had it in the shop over the summer to have the spring on the track replaced I gave them two rollers to replace.  They replace one that was still good, not one I told them to do.  They did not offer to fix!  I'm looking to see if there are other repairs shops here in Columbia SC.

What is your tractor S/N ?

Also the ring and pinion may be toast too.

The seals on the left clutch piston will fail, maybe also damage to piston etc, the reason is the crown wheel is on the right and as the bearings fail on the cross shaft the left side has a lot more movement.

The other comment I can make is the language you use is not conventional and as such makes for confusion, maybe why the wrong roller got changed.

Clutch levers forward, clutches engaged.

Clutch lever pulled back, clutch disengaged.

Regards, Wombat

I do appreciate everyone's comments.  I've never owned a dozer before but did show the shop manager which rollers to replace.  He failed to show his 'young' mechanic (probably because it sat on the lot for a month).  Not sure what the S/N is, would have to try to find it.  I had a senior Cat field guy out once and he couldn't find some of the ID numbers, that's before the spring was replaced which was at his suggestion (and rollers).  .  

If you have the correct year a U.S. built 1968 D6C powershift would be a early 10K serial number. You need three books: the Operation and Maintenance Instructions, the Parts Book and the Service Manual. These books will save you a great deal of time and money. The Service Manual at almost $200 is cheap for what it can save you.
The O.M.I. was not available at this time but check back on eBay.
Craig
Parts Book $34.00
www.ebay.com/itm/385069877439
Service Manual $195.00
www.ebay.com/itm/195266280045

BTW, if you find our help useful please join our club. We cannot continue to provide the service we do without paying members. 
Craig

Need that s/n. The D6C 76A and 10K overlap in 1968.

Old Magnet, weren't the 76As turbocharged and the early 10Ks naturally aspirated? That would make it easy to tell.
Craig

The dozer does have a turbo charge on it.