D4 special tools part number

Side-seat I plan to buy one of those tools from general gear. The other tool I'm looking for is an adapter that screws onto steering clutches shaft and also pinion gear shaft. It can be used with a puller to adapt puller leg to either shaft.

Just looked trough some pictures of the last time I was into D4 steering clutches but can' make out the thread size on the ends. Perhaps 1"-12 or 14 TPI.
Removal: all you need is a suitable bar puller for example: OTC 927 or 938 with some B7 all thread and heavy washers and nuts hollow hydraulic ram  and sledge hammer to pull the steering clutch packs.
Installation; All I did was weld some Gr8 heavy nuts together to adapt to the all thread 1"-8NC I use in my 30T hollow ram to press them back on to specified tonnage. I also made a spacer or standoff out of some seamless tubing so there was enough room for the nuts to do their push pulling. 
Funny thing; My pictures have at the time, my 3yr grandson using the port a power pump pressing the clutch packs back on. He's 6 now and has just finished rebuilding his first Kohler 12hp engine on an old Cub Cadet tractor a friend gave him.
 

I do have a 17 ton crossbar puller. I'm considering buying a hollow ram and pump to do this work. You're grandson getting an early start on building up his bank of knowledge.

Jimmy, I used a hollow ram when I did the 5U which enabled me to both remove and install the hubs

I will plan on purchasing a hollow ram. I spoke with my local caterpillar dealer about rebuilding steering clutches. $195 an hour. Seems well worth it to buy tooling.

I had my local machinist turn down a couple of adaptors and bought some threaded rod etc. to make up the pulling arrangements. I bought the hand pump with the ram that includes a pressure / tonnage gauge so I could see how much I was pressing the hubs on. The D2 snuck in using 20t equipment (Hydrafore) but you might need a bit more for the D4?