IH 766 Clutch Problem

I've got an IH 766 Diesel that has some sort of a clutch problem. The tractor has been well used (apparently it has over 14 thousand hours) and I got it second hand 2-3 years ago from it's original owner. It was in good condition.

I have been using the tractor for the past few years for doing all sorts of things ranging from cutting the grass to pulling stones that weigh as much as the tractor itself (5-6 tons) at did all of them without a fuss and no clutch slipping whatsoever. I just pulled a 4 ton stone out of the ground last week, also without any clutch slipping.

Today while cutting the grass, I was climbing a gentle slope when the wheels seemed to have lost power and the tractor slowed down, stopped and then rolled to the bottom of the slope. The engine & PTO continued running as usual. I didn't press anything or move any levers, it just happened by itself. No sounds or bangs or jerks or anything, the wheels just lost power without any other signs of anything happening.

I tried taking the tractor out of gear and putting it back, I tried changing to various gears, I tried the TA and nothing got the tractor going. It just moved forward a few inches then rolled back. I haven't tried going backwards. I concluded that something happened to the main transmission clutch but it is a very strange way to fail. No advance warnings or gradual wear or even indications that it even happened when it happened other than the wheels losing power.

I am perplexed. Is this a normal way to fail? What has happened to my tractor? How much will it cost to get this fixed? I am very worried.

Tomorrow, a mechanic friend is coming over to take a look. I hope it isn't some major failure and just some minor things that need adjustment. I am in the city right now for just a few hours and will be back at my farm tonight where this is no internet. I will be back in the city where there is internet sometime on friday or saturday.

Probably not the clutch.

Probably not an easy adjustment.

My money is on the TA.

check the hydrolic level.

the cross inside the punkin on the rear end broke with junkyard parts and a days labor about 500 in parts will fix it, at your local dealer about 3750 to 4500, both axel housings, top rock shaft, pto must b removed we had a 1466 do this about 6 years ago a 1066 last year both fixed with salvadged parts both still going , the cross we put in the 10 was out of a 706 gas looked like new the one in the 1466 was out of a 560 just a shade shorter but has held up fine

I want to hold mkirsch's money!

when the mcv pump got weak on my 1066 whenever I would idle it down at the end of a row it would loose pressure and i couldnt drive the tractor at all until the pressure built back up. If you dont have power steering its your mcv pump.

when the mcv pump got weak on my 1066 whenever I would idle it down at the end of a row it would loose pressure and i couldnt drive the tractor at all until the pressure built back up. If you dont have power steering its your mcv pump.

one other possibility that hasn't been mentioned- this happened on our 986- if the cushion springs in the clutch disc self-destruct, then you'd lose transmission but not pto and hyd. the outer part of the clutch disc would be driven as normal, but not the spline in the center.

I fixed the tractor myself on tuesday with just a piece of 1/2" keystock! You wouldn't believe what had happened.

The axle was turning in the wheel! The axle is a splined shaft and there were 2 x 2 teeth in each wheel. God knows when, the previous owner of the tractor broke all 4 of the teeth on the left wheel and then repaired it by welding on one iron tooth to the cast iron wheel - not very strong. I'm amazed that the tractor lasted so long with such a crummy repair. To repair it, I cut a triangular groove about 1/3" deep in the forged removable part where the axle meets the wheel and fitted a square piece of 1/2" high strength steel keystock where my groove and the matching grove in the axle meet to form a square. I then gave the 2 bolts holding that forged piece a hell of a tightening and now the tractor's working great. I am very relieved now.

Thanks for the help anyways.