RD4 4G Ring Gear/Starter Gear

[Stuss]

Pulled the motor out of the RD4 S/N#: 4G7571 on the weekend due to the ring gear no longer being attached to the flywheel!! It appears to have got seized/jammed on a bolt which had dropped out of starter pinion and when we towed it to when it first got home, sheared the three headless set screws off. It appears that the ring gear was cracked for some time. If any one has a spare ring gear they don't mind parting with or we we may have to take a last resort and weld the crack up and weld onto flywheel (any tips on this?) Also is the ring gear the same for all the D4400's??
We bought the RD4 from the original owners at Lake Grace and they purchased it orginally from Wigmores in 1947 installed with a Le Tourneau Tiltdozer S/N#: D4392A4 and Power Control Unit TE S/N#: P52988TE
Will post a picture of its current state in the next few days.

[Old Magnet]

Looks like there is going to be more to the story

4G7017 - 8449 uses gear # 3B7307 and 4B1290 machine screw retention and was used up to 7J75 only.

You would have to go back to 4G1 - 2480 with gear 2A3490 to find the 1/4-20NC x 5/8 headless cup point set screws.

They are all 112 tooth count so it appears the retaining method is what changes.

[Stuss]

Thanks for giving us more clarification Old Magnet. We double checked the Ring gear and the part number is 3B7307 with 112 teeth, but we looked in our parts book (for the early RD4's) and that lists it as a 2A3490 111 Teeth?? More confusion!! We might be able to get a 7J and use the ring gear (& flywheel) out of that. What is your opinion on welding it together and on to the flywheel (as the very last resort)?? Here's some pictures of the RD4 when we first got and us towing it behind the Fordson (Which is the Blue thing currently being put back together as the RD4 gets pulled apart!!) and a couple pics of the Flywheel to see. I will admit that towing the Cat behind a Ford was probably what caused the problem!!!

[Old Magnet]

Looks like your parts book has a typo...I checked again and it's 112 teeth...Form #8126 (1955)

I would look into changing the flywheel/ring gear assembly. I'm the wrong guy to ask about "butcher" repairs.....although I have welded a split ring gear once when there was no option. I suppose it could be welded in place but why set up a potential future problem.

Tow starting an unknown tractor.....especially one that is locked/bound up is always high risk.

[OzDozer]

Stuss - I roamed around most Lake Grace farmers back paddocks for over 25 years .. and I never spotted THAT tractor!! ..
That's a good find .. that must have been amongst the last LeTourneau blades and PCU's sold in Australia, as Cat PCU's appeared as early as 1939, and the revised line of PCU's appeared in 1944. In addition, Cat blades appeared in 1946, and possibly the only reason a LeTourneau was chosen, was because of the major price differential.
LeTourneau's Rydalmere factory was still in full swing in 1947, and Australian-built blades didn't have the huge tariffs atttached, as the genuine Cat blades did.

I'm picking up that RD4 from Woodanilling on Tuesday, so I'll give you a report on whether it's a parts tractor, or a restoration proposition.
As I mentioned to you at Dardanup, those farm idiots threw all the sheet metal and loose parts in the scrap bin last year, during the scrap frenzy, so I think she may be past restoring. It's only the good work of one old fella, that saved the main part of the tractor from going to J&P Metals.