were all of the D6 8U 9U series tractors geared the same?  or was there a Special Application model also in that series?  Thanks

I wouldn't call it a Special Application but yes as an attachment there are different transmission ratios.

thanks magnet. so a D6 9U with a hydraulic hard nose and blade would have a different gear ratio than one for agriculture? most likely?

Somewhere in 8u,9u build time Cat started to add Transmission Group tags, maybe only added if other than standard gearing was used. If you look in the parts book more than just 2 or 3 groups available.

I have what I believe was a 9u farm Cat with over 10,000 hours that has had a hardnose and cylinders for running a blade added. My hour guesstimate comes from numbers scratched into the paint on the hood before I got it. Assuming it was a reading when the oil was changed.

So by the odds bursitis your right. Then start looking a the spring and front idler to see if they are the more leaves and bigger diameter as generally used with a dozer. But if not on west coast of USA probably not many farm tractors having a hardnose added.

thanks Ray and Magnet. i was watching a late maybe 59 model D69U with a hardnose and straight blade and a 5T D4 salvage tractor sell at auction. i didn't get either one because transport would be to much. but i will keep looking and learning as we go. Thanks again