After the sales agreement with LeTourneau in 1944 and the introduction in 1946 of the no-25 Caterpillar offer this cable control.

Has anybody more information on this?

Hi Quad,
That is a 9R series ccu that came out prior to the #25. It is a worm gear drive that came in both single and double drum versions for the D6,7,8 (about 1942)
I have both the Sales/specifications brochure (4 pages) and Parts Catalog covering the single drum 2S5001 to 2S5500 and the double drum 9R1 to 9R2460.
They are a pretty rare attachment now.
Attached brochure:

OM I,ve seen lots of cable controls come in the shop and have worked on some years ago at the dealer but can,t recall seeing one like this control so they had to be pretty rare, esp. around this area. The 8s & 9s that were used in the coal strippings here back in the 50s and later most of them had cable controls on them but in the later years they went then with the hydraulic blades.

Hi SJ,
Yes, they were probably pretty rare back then to......based on those serial numbers not many were produced compared to over 50,000 of the #25 units.

I don’t have anymore to add about your question, but here is one bolted up.
Kelly

Thanks for the information.

QuAD - The Caterpillar CCU you have pictured, was released in February 1941, and an installation/maintenance booklet (Form 6497) and a service instructions booklet (Form 6630) for these units (double and single drum), were provided with the Caterpillar Service Magazine, dated Feb 20, 1941.

Initially, these CCU's were not provided with any S/N. In the Service Magazine dated May 29, 1941, the following advice was given ..

"The rear mounted CCU's being shipped from the factory, now have 9R S/No's assigned to them. The earlier units did not have serial numbers, but these have been mailed to dealers for installation in the field.
When service reports are written, please give the S/N of the CCU, and the S/N of the tractor upon which it is installed. We do not have History Folders for CCU's and will need the tractor S/N to properly handle your report."


From S/N 9R806, around 1944, the CCU design was improved when it was fitted with an automatic brake that automatically disengaged when the clutch was engaged. This necessitated a new method of brake adjustment, as compared to S/No's 9R1 to 9R805.


What is more interesting, is that .. despite the fact, that this type of Cat CCU is rare .. there was actually an earlier Cat CCU, available in both single and double drum which was released in August 1939, and which was featured in the Caterpillar Service Magazine of August 21, 1939, with two plan drawings of both types of CCU's .. plus two installation/maintenance forms (Single Drum - Form 5681 .. and Double Drum, Form 5291) .. which stated that the Double Drum CCU was designed to be fitted to the D8, D7, D6 and R5.

This very early Cat CCU used cone clutches, in the same manner as the LeTourneau PCU's of that era.

I have copies of all the above-mentioned Service Magazines .. and the CCU installation, maintenance and service forms, as listed above, as well. If you wish to acquire copies of any of these, please email me and we can work out the fine details.

Here are two pics of the very early Cat CCU's, from the 1939 booklets. These also, apparently, did not have Serial Numbers issued to them, and it's possible they may have been essentially prototype, or experimental models.