The #6 shovel and later direct drive units are all oil clutch.

So I went to look at the machine today. I got a few more photos, the bushings were very hard to photo with the light. They look almost new. It looks like the block froze and someone has tried to repair it. Is the block cast iron or steel? The radiator fins fall off when you try and clean the gunk off. The engine is free. No water in any oil I could see, but it may be at the bottom. The tank is mostly full of diesel with no rust in the tank where the metal is exposed. Does the 9u serial number on the engine mean it's a transplant? The undercarriage is definitely bigger than my 9u. They are asking $4000 Canadian but the guy said he would take $3500. I said I wanted to hear it run first. The left steering clutch has resistance but the right has nothing. The guy said when he was parking it, the lever just released suddenly when he pulled on it really hard. Broken link pin maybe? Or wrecked pilot bearing? What do you guys think about the price?

Yes, engine already is a transplant (same as late 8/9U) with provision for direct electric start.
Same drive line components as D6 but transmission gear ratios are different.
Weak point is pinion/bevel gear shaft as it is still D6 component. Eventually the shaft got beefed up in much later (different) models.
Pilot bearing has nothing to do with steering clutches. Might be an issue with clutch release bearing but linkage would be the thing to check first.

Thanks Old Magnet! I guess I was calling the clutch release bearing by the wrong name. What is the pilot bearing then?

Pilot bearing is usually referred to the one in the flywheel that supports the main clutch shaft or the torque converter shaft in some power shift machines. Also can be the float end of any shaft anchored in bearing at one end and free to expand/contract at the other end (pilot).

I bought the 977 today! I got it to start, it fired right away. It smokes a bit blue and has a slight govener surge. I got it for $3200, it seemed like a good deal.It turns out, it's not the clutches that are seized. It's the pistons in the hydraulic booster. They are stuck in their bores. I cannot go forward or backward. Is there a trick to freeing them or does the booster have to come out? Not so easy with the hydraulic hoses for the loader right above it. Any tricks or hints would be much appreciated.

good stuff i glad to hear you got it. glad to hear a fellow Canadian has not got yellow fever too. if there the same brake booster have a look at the 2 links might help you out? they may just be low on oil and that's why they don't come back out could just need new seals. keep the info and pic come of your adverncher in getting her running.

www.acmoc.org/bb/showthread.php?23412-D6...maintance&highlight=

www.acmoc.org/bb/showthread.php?14587-D6...ong-years&highlight=

The rod with spring that pushes on the valve in the booster comes out easily. What makes the valve come back to closed? Is it possible that my clutches are stuck open, creating the loose clutch lever feel?

When I open the cover on the top of the booster there is about two inches between the end of the push cups that have the holes in the end, and the lever that goes down through the booster body. Is that supposed to be tight?

With everything working right and adjusted these are the clearances you should have.