What is wrong in this picture?

I have not done a "what is wrong in this picture?" in quite a while. This is from Form P-1170. It is possible to look at what is wrong in two different ways in my mind. Cat fixed this problem with a reprint that was glued over the top of this drawing. I bought this form because it had water damage, and all of the glued-in fixes were loose. Better yet, what is the serial number range of this tractor? There are a few other minor mistakes too.

Thanks

Ken

As with all drawings - there are possible errors -- There is a measurement from sprocket shaft centerline to the sprocket teeth that is depicted in decimals, not fractions. It appears there is a difference of 3/16" between center of sprocket and the center of the front idler shaft. No dimension notation on the top roller even though the vertical center line is drawn. Track roller frame is not marked for elevations above ground level. Much of this is subjective, depends upon what detail one is wanting or expecting. This is truly only one portion of a "big picture" where other drawings most likely fill in the "blanks". - cts

I am looking at something else. I did not get into the dimensions at all. The 28 7/16 inches on the centerline of the crankshaft would be good to see if the spring needs work, but that number is only good if the rail, rollers, and grousers are spot on.

Only three rollers? I'm not familiar with the Twenty so don't know if that's right : )

I believe the Twenty has 4 roller track frames by my sales brochure photocopy, and my General Instruction Book for Early Products similar side view of machine. Looks like someone goofed and amendments were made with a stick over as you describe--happens to the best of us at times.

The Holt T35/2Ton has a 3 roller T/F system.

Eddie B.

I

L/PL Twenties, Twenty Fives, Twenty Eights, and the R3 all used 3 roller track frames. The chain links and rollers are the same as on the S/PS Thirties. The 8C Twenties used a 4 roller track frame, the 8C is a PV Fifteen with a few improvements. Fuel tank moved, exhaust through the hood, seat back with the corners cut off at an angle, carb moved lower and a few other things

Missing the front idler guards and the proper castings to hold them on. The engine louver panel has oval holes and a different latch. Maybe the drawing is later for the Twenty-Five and they forgot to remove the radiator side castings. Were there any 25's with curved fenders? Casting holding the sprocket guard id the larger style used on the 25 &28.

I'll have to look at my books.

Missing the front idler guards and the proper castings to hold them on. The engine louver panel has oval holes and a different latch. Maybe the drawing is later for the Twenty-Five and they forgot to remove the radiator side castings. Were there any 25's with curved fenders? Casting holding the sprocket guard id the larger style used on the 25 &28.

I'll have to look at my books.

Steve got the big thing I was looking at. This is what I noticed. This drawing was for Twenty series PL6320 and up, which was renamed the 3C Twenty Five. From what I can figure, Form P1179, Servicemen's Reference, and Form P1170, Operating Instruction, were both printed with the idea of a Twenty with the upgraded final drives and track frame tin work. Both of these books were patched, both on the cover and in all references inside, from the Twenty to the Twenty-Five. I believe this same drawing just kept getting updates as changes to the tractors were made, but things were also missed along the way like the hood doors. The hood doors have 40 louvers, and the hinges are wrong for a late Twenty or early Twenty-Five. The hood doors changed from 40 louvers to 31 louvers around April 19, 1928. The hood doors were also changed to the removable style at PL4695. Steve is also correct that the hood latch is not quite right. The grousers are also the type that was used on the earliest L/PL Twenties. I have attached a picture of the drawing that was used to patch the Operating Instructions book, where the radiator side was changed from Twenty to Twenty-Five. And pictures of the two books, one that has the Twenty-Five patch still on it and the other where the patch has fallen off.

The Twenty-Fives did have the curved fenders and the L/PL seat until about halfway through production.

Fun to see all the little changes side by side, makes you wonder why Cat had so many different versions of the same tractor even they got confused printing the manuals?