I've done an almost full rehab on 5U13753 (all but the actual undercarriage) and the durned pony pinion hasn't stayed in good shape. I didn't pay much attention to the pinion gear but turns out it was worn enough internally (ID and splines) that it was jacking the latch sleeve retaining bolts which as you all know don't have much purchase. I've worked with plenty of worn junk before but turns out that the pinion gear needs to not be worn much at all on the inside. I think mine might be a combination of worn and eroded. Anyhoo, I have a good used one plus a pair of latches coming from Dana at Florin. I'll take the stop down to my guy and have him skim the surface 020 so's it's "perfect", and I already have a new latch spring. If the new pinion gear is still a bit loose, I might spring for a new one - not cheap but definitely cheaper for my time than the 3.5 hrs plus travel time I spent removing the pinion assembly this time (3hrs 29min to remove the components needed to get the pinion out, and 60 seconds to actually remove the pinion assembly..... I've had every single nut and bolt apart on that tractor so nothing fought me, but it just takes time to work through everything. It would have been good if Cat had made the pinion assembly able to be removed without lifting the pony - then it would have taken ten minutes to remove the rear cover of the governor, the front cover of the pinion assembly, and finally the assembly itself. Since I've just done this, here is a list of everything I had to do to remove it, plus tools needed (some were not actually used such as the paint scraper since all gaskets were either greased or anti-seized during the prior assembly):Tools- Red toolbox!!- 1/2” drive sockets and extensions, 3/8”, 1/4” too- ratcheting spanners- scraper for loosening gaskets- empty oil jug to drain pinion drive - 1 gal- two short pieces 2x4- jimmy bar- plastic pan for hardware (stays there)- yoghurt container lid and painter’s tape for plugging holes temporarily, other plugs- paper towels- gloves From Lowes, two 5gal buckets with lids for coolant. Drain coolant at main radiator drain and at rear block drain, drain pinion gear chamber, remove hood, main air cleaner, detach starter wires, remove pony air cleaner, remove pony gas tank, loosen gauge dash, detach ammeter wires, detach oil pressure tube, detach temperature sender at cylinder head,remove gauge dash, remove rear cylinder head to pony water elbow, remove pony exhaust pipe boltsat main engine manifold, remove decompression rod, loosen remote pony fuel bracket, loosen pony nuts (8 of), hoist pony 2” first on passenger side then on driver’s side and blockwith 2x4 (remaining coolant from pony will drain to ground), remove governor rear cover, remove pony pinion rear cover, latch pinion, undo pinion assembly bolts, extract pinion assembly, cover various holes.Fix pinion.

I had the same challenge removing my assembly the first time, but I learned that there's a slightly thinner section o-ring that can be used instead of the one listed in the parts catalog. That, along with ample anti-seize and oil meant the second time, it popped out easily. Actually, I do see slight movement in the assembly in the hole when it's powering the main engine so I'll need to figure out a way to address that. Tightening the four bolts is insufficient to hold it still. I'm thinking possibly two small blobs of weld at 90 degrees apart that aren't stuck to the assembly but essentially "jam" it up against one side of the flywheel housing. I could go back to the original parts catalog o-ring but that was hard to even install fresh with lube so I don't want to do that

Oh yes, and it's always good to go around and confirm that every nut and bolt is out before trying to crowbar parts off : )

I’ve bit the bullet and ordered a replacement pinion here;

www.tpaktopc.net/images/catcrawler/CAT_6B1360_PINION_GEAR.JPG

Feels a bit lighter than the original but hopefully will do the job..


 

Wow, that one looks nice Tony!
Outback, I'd just turn down a piece maybe a half inch thick, weld that on, then put a button on it of whatever size gets it back to spec. You could probably put some fill in the hole so the spring has a bit of support but you don't want the center to be proud such that the spring then prematurely wears out in the middle - you need a nice rounded surface on the inside. Maybe weld it, then put a rounded mill cutter down inside to profile the weld material back down

Also Outback, be sure to let us know how snug of a fit that pinion is. Even if the one from Dana is ok, if John's one is nice and snug, I'll go with that and keep the other as a spare