d6-9u and 977 traxcavator

Hi Guys

There is a 977 traxcavator for sale in town, the only problem is that the serial number is 20a3946 series E. Now if my researching is correct after serial number 20A25xx the undercarriage was changed from a D6 style to a D7. So I guess there goes the idea of putting hydraulic adjusters on my old six, or is there a way they could be fit?

If cat put a d7 undercarriage under a d6 based machine.....would there be any advantage for me to trade them around? My sprockets are very well worn( out ) rollers need a build up/replace, chains/bushings are not bad.

But I guess the blade frame would not fit also.

Yes, they changed to 8" pitch (D7) tracks at s/n 25009.
No, the D7 hydraulic adjusters will not fit on the 9U but you can still get 9U adjusters.

You'd have to check gauge and overall width to see about fitting your blade frame. D6 Trunnion mount would most likely have to be adapted or upsized to D7 mounting.