Hi OM;
Thanks for the info. I agree, with the constant turning of a loader machine, think you would want double at idler and I think at sprocket. However, looking over your sketch, it shows a single flange at the sprocket in all cases. A double flange aligning chain with sprocket would be critical??
The suggested CAT arrangement disagrees with what is stated in the servicemans book. What to believe?????
Think I will follow what is shown in your suggestd arrangement except use a double as #1 behind idler.
Do you see a disadvantage of using; double, single, double, single and double. My thought process would have double flanges aligning with idler and sprocket.
Thanks for the help
Frank Gross

In all cases the roller next to the sprocket should be a single flange. Has to do with capturing alignment as the rails come off the sprocket....or something like that:)

The 955C became the 955E in 1958 at serial number 12A5793 and used D6 size undercarraige, I've seen later ones than this but never with the D330 engine, they used the D315 4.5" bore engine, the D330 was used in the 955F 45A series introduced in 1960.

Hi Catsilver,
I tend to agree with you...I always thought the entire 12A series was D315 engine until I read otherwise....but now I think it's bogus information. What doesn't make sense with a D330 is what happened to the chassis as I don't believe a D330 would bolt up to the 12A case and the main case did not change until the 60A series as far as I know.

Problem is there really doesn't seem to be a service manual for the 12A 955 so all there is to check with is the 7U-D4 materials plus the separate loader parts manual unless I'm missing something. Your comments please:)