I have a D4  6U with seriously stuck steering clutches. I may have available rebuilt RD4 clutch packs, but dont know if they are interchangable..  Any ideas?  Thanks.

My gut feeling is they should fit, the 6U and early D4 share the same basic transmission and final drives, with certain minor upgrades, I reckon there was a discussion here recently about beefed up cross shaft in later D4.

Do you have the parts books, if not, have a look on the General Gear website, John Parks sells new clutch plates for most older Cats including the D4, his lists will show if there is a interchangeability with clutch plates and brake drums.
Mike

Thank you Mike. I will check out General Gear. I have an RD4 carcass on the ranch that I think had all new clutches installed before it was parked forever. I am still trying to free the clutches in the 6U without much luck. Even if the RD4 parts dont fit, I can know more about what to expect if I have taken it apart before I take the 6U apart. When it stops raining I can work on things. Thanks again. Grant.

Well Grant, once you pull the cross shaft and stuck steering clutches out, you will have the chance to repair or replace them, either way you are going inside the backend of the 6U aren't you, and will get your tractor sorted. One big difference with RD4 and later 6U is a change from straight cut teeth on the crown wheel and its pinion shaft, to helical cut teeth, so the cross shaft with clutch packs is not a straight swap, though both cross shafts share many same parts, like the bearings.

The job looks worse than it really is, the seat box and fenders are not hard to remove, on my 7J I got them off as one unit, the tranny top should have the split cover over the main clutch housing, you will need to disconnect the gearbox interlock, and brake linkages, if the tranny top gasket is not damaged you can re-use it with a suitable sealant, you will need to roll the tractor along using a small jack on the grouser bars to rotate the brake drums to remove their bolts.

One tip I learnt by accident, when you go to lift the cross shaft out, it is heavy, so use a chain, not any thing flexible like a tow strap or snap strap, those cross shafts are bolted in tight with cork gaskets top and bottom, and kind of glue themselves into their saddles in the tranny, so it can take a fair bit of force to pop the cross shaft loose vertically, and when they pop loose, they CAN spring up in the air as they release if being raised with a soft strap, only to fall back into the saddles, with the teeth of the crown wheel hitting things as it comes down.

Don't ask me how I know this, but luckily the damage to a crown wheel tooth was minor, but it could have been major very easily! LOL

One of the guys on here has a thread running right now and a good youtube series running on youtube about this exact job, removing and repairing the D4 steering clutches, look for Pacific Northwest Hillbilly on youtube, it will be time well spent. 

I assume the steel plates have rusted and swelled, so it might be as easy as cleaning them, that would be a nice cheap result, because you will only be opening up one backend, not 2, though think about replacing the steering clutch thrust bearings while you have the shaft apart, if the clutch packs are rusted solid, those bearings will be toast, just a heads up though, genuine Cat thrust bearings are not cheap.
Good luck
Mike

Another tip is to back off the bevel shaft bearing adjuster rings so the bevel shaft can move sideways and the bevel gear and pinion teeth can move apart further for easier removal and so are less likely to jamb and chip the tooth ends.

Cheers,
Eddie B.

I did a reply and it didnt post. Another of my wrong button events. Thank you guys very much for the info. I am going to print it out and keep it handy. The RD4 is slowly being parted anyway, so I will pull it apart for the learning experience. If there are usable parts it is good for me, if not then it is OH WELL. I will look up Pacific Northwest Hillbilly.

Thanks Again, Grant.

The only real challenge with the job Grant, is you need a decent puller to pull the clutch packs off the cross shaft, they should be on there really tight, and then you need a big enough shop press, or suitable hydraulic pusher, to press the steering clutch inner drums back on the cross shaft at the proper tonnage, which is 20 tons according to my Cat D4 workshop manual. Eddie will confirm if that is OK on a rebuild, or if you can back that pressure off for a older machine, don't want to be cracking anything..........

You will need to fabricate a tool to compress the clutch pack springs too, you can buy a fancy one from General Gear that does them all at the same time, or knock something up that does one, or 2 at a time, you might find the springs and locks are rock solid with rust, be warned if you use heat to free them, your springs will be ruined, but new one's are available from General Gear, John Parks is a good guy to deal with.

Florin Tractor had the gaskets needed for the cross shaft when I did my 7J.
Mike

Hi Team,
despite the books saying 20 tons it is too much for these old jiggers,
At the Dealer we used to use 12 tons on advice from Caterpillar and never saw an issue of one coming loose out the dozens and dozens of D4's, and 955's we did over the years.
The first one I did as an Apprentice I split a new bone dry and clean hub at 20 tons following the book specs.
I went to the foreman with cap in hand and he said it was his fault for not telling me to use the lesser tonnage.
Others on here have disagreed with this lower tonnage in the past BUT I personally would not use anything else but 12 tons on these.
Ensure the tapered splines are clean of oil, rust etc. or you could be in trouble.
Cheers,
Eddie B.

i haven't tried this on steering clutches so take with salt. but i think that ballistol would work good for stuck steering clutches. i would buy a gallon of ballistol and plug the clutch compartment and fill with water and add 1/2 gallon of ballistol and let it soak. and before you drain it out work it some to loosen things up.

I am not familiar with "ballistol". Is that an acid or some other type of rust buster? I was going to try the citric acid soak, but it was recommended that it be warm. Everything is hovering around freezing and wont get much warmer until spring. I also could not find any citric acid in enough quantity to be helpful. I can get muriatic acid by the gallon, but I dont know if it would be correct or if it would do damage.

I just arranged with my niece to use her barn for the work. That beats the heck out of working in the rain and dirt. It is going to be interesting to steer the tractor thru a few hundred yards of woods to the barn. Chains and my old 4by4 will have to move it left and right enough to drive and then a 90 degree turn at the barn.

It is raining this morning so I am going to research General Gear and the Northwest Hillbilly. It is all fun. Thanks Folks. Grant.