for the steering issue try adjusting it first and see if you have any joy. the method would be in the owners maintnance book or service reference. its worth a try and its cheaper than parts.

Adjustments to the steering clutch did not get it to unlock.

I committed to pulling it out of there. Actually not that bad, as heavy equipment repair goes. Cat designed this well.  The worst of it was working out a way to get the bolts out that connect the stub shaft flange to the rest of the transmission.  A 15/16 open end wrench could get to them, but they were too tight for that.  Couldn't get the box end on due to the angles.  I ended up having to customize a socket to get it in there.



After that, she pulled out okay, using the recommended slinging strategy.

The stub shaft was SERIOUS about not wanting to come off of there.  20 tons of pressure... nope.



Gentle heating didn't help...




I committed to putting more heat into the casting.  My concern is two fold - one, heat will destroy the springs, increasing costs.  Two, I don't know if this is cast steel, or cast iron, but too much heating on cast iron can cause issues.

That said, stripping the threads in the casing would also cause issues.    More heat did get it to pop loose.

From there, it was a matter of setting up the press plate and popping the springs out.  Not too bad.




The clutch frictions and steels have a fair bit of corrosion between them.  There's some pitting in the steels.



I'll be replacing the frictions, springs, bearing, and O-ring in this assembly, as well as cleaning up the steels.

I'll also have to deal with this damage:




Not great.  Probably as a result of the heating I had to do to get the stub shaft out.

Fortunately I have a fair bit of experience dealing with cracked cast iron.  The procedures outlined in the AWS brazing handbook have been very effective for me, and while this will cause some work, it is repairable.  Shame it happened though.

The cracks are on both supports.



Dye penetrent testing showed one side wasn't too bad...



The other was much deeper

[img] https://imgur.com/WxjfE0r.png[/img]

Grind them out...




And braze them up.

No in action shots of brazing.  Brazing involved a preheat to 600F, surface pretreatment with an oxidizing flame, and ensuring proper wetting before moving up the joint.  It was then insulated with a thermal ceramic and left to cool very slowly.




After cleaning up the braze... looking good.  I had a few places of underfill, but this should be just fine.

I can replace this part for $190, plus shipping, so I'm on the fence if it was worth repairing.  But I thought it worth an attempt - if nothing else fixing things that are replaceable is good practice for fixing things which are not!

what do you mean by wetting?

Braze, like solder, must flow out onto the base metal, forming a bond with it.  Imagine water sprayed on a freshly waxed car.  The water beads up, it does not spread out in a film on the car because the wax repels it.  If you attempt to solder on some copper pipe that has not been freshly cleaned with sandpaper, it will do the same thing.  The solder will ball up, and not attach to the copper at all.  This is because there is a layer of metal oxides which does not allow the filler to come in contact with the underlying metal.

For soldering and brazing most materials, you must have a clean base metal, it must be hot enough, and ideally you want some flux to chemically clean any minute traces of oxides that remain.

Cast iron adds some more complexity - when it is molten, it contains so much carbon that the iron can't absorb all of it.  So, as it cools, some of the carbon ends up as flakes of graphite all throughout the metal.  You can't braze or solder graphite, so it must be burned out of the joint prior to brazing.

Then, when brazing, it's important to make sure that you base metal is getting hot enough for the braze to flow out on to it.  The braze can't just sit on top of the cast iron, it must form an intermolecular bond.  You can see it happen when the filler flows out over the base metal.  We call this wetting action.

The very early serial numbers' steering booster oil pump shaft (behind the drive gear) is a smaller diameter. I can't find my darn parts book, but there was a serial number break relatively early on where that changed to the larger diameter shaft. Lucky for you, I'm sure yours is the later one that the Cat dealers stock seals for. The only place I found a seal for my early serial unit was Florin tractor. It was a very old NOS leather seal. I was skeptical that leather that old would not just crumble apart instantly, but it's holding up just fine so far. I was lucky I revamped mine when I did because shortly after, Florin closed their doors and threw most of their old inventory away in scrap bins. Before re-sealing my entire steering booster unit, I used to call my machine the Caterpillar-Valdez because of the puddle of oil it would leave on my shop floor.

When you remove your booster unit from the tractor, there will be two splined shafts sticking up from the case of the machine. These are what the booster unit is actuating hydraulically to operate the steering clutches. When the linkages to the steering clutches are disconnected from the yokes connected to the underside of the splined shafts, these splined shafts should turn very easily by hand. One of mine was acting semi froze up. It would move but it took wayyyy too much force. We played hell to finally get it unbound and moving freely. Mostly by dousing the base of the splined shafts with a combination of various penetrating oils (Kroil and Schaeffer's Penetro 90) and working the shaft back and forth a few times a day for several days until the oil eventually works its way down in between the splined shaft and the bushing that the shaft turns inside of (I forget what exact size socket we used that slipped over the splines and worked out without damaging them). Best of luck.