7600

[Bob seND]

'75 model 7600 new project. Starts good, but misses with blue smoke for about one minute before it smooths out and runs well. Once smooth, it doesn't smoke unless accellerating, then brief nice black smoke. What is the likely cause of the missing?
The 3-pt also sinks all the way down, and with a back blade on it I must keep my hand on the lever to keep it up, then when raising it it is very jerky.
I've ordered a hydraulic filter and will get the 15 gallons of hydraulic fluid (ouch) to change this weekend. My owner's manual is on the way and I don't fully understand the 3-pt settings yet, but it doesn't seem right the way it is. Any thoughts?
Bob seND

 

[Fordfarmer]

Should be a '76 model, although it could have been built in late '75. '76 was the only year for the 7600 row crop.
If you have to hold the 3-point lever, the lever needs to be tightened or have it's friction disk replaced. At the point where the lever is attached, there is a nut with a spring under it. Try tightening this a turn or so. Fresh oil and a filter may smooth out the operation of the 3-point. I don't have my book handy, but I think it's 55 quarts for the trans/hyds/rear end.
I'm not sure on the missing, but it may be a bad injector.
You've got a nice tractor there, especially with the dual power transmission.

 

[kyhayman]

Most likely the jerky movement is water contamination or dirty fluid. A fluid and filter change should help but some 'hickuping' of the 3pt is to be expected on these. If this doesnt fix it its major work inside the lift cover with questionable results.

 

[RodinNS]

Where to start.......
Bob, did you buy this thing from someone you trust to know what it is, or some jockey?

To start with, I don't think you have a 7600. You have the forward sheet metal of a 7600 piled on top of a 7700 as suggested by the large instrument cluster. I'm assuming that the tractor also has suspended brake and clutch pedals like a car would have as opposed to conventional straddle pedals like the 7600 would normally have. I don't see foot boards for the 7600 OR a flat deck that the 7700 should have but the pics are a bit distant for my eyes.
It also has the row crop front axle with hydrostatic steering rather than the utility axle with an integral power assist and drag link that the 7600 should have....
It appears to have the 7600's fenders.
It would be good to know exactly what it is should you need parts since there are differences. I'm also curious about how or where you put fuel into this beast? Is the filler under the hood?

Since you can't trust what's on the hood tag, look for a horizontal flat spot to the rear of the starter on the transmission housing. You should see three lines of numbers stamped there. Get them if possible and post them and hopefully someone will decode them. I'd have to look in a book myself to decode that model number. It also will not be a '75 model. It will be at the earliest a 76 model that might have been built in the last quarter of 75...

Now, to the problems you have. The miss is most likely due to either a bad injector or a bad cylinder (rings/piston issues). You could start the tractor and open the lines one at a time when it's running rough and see which cylinder produces the LEAST stumble when you open the injector. That will be the poor cylinder. From there you can switch that injector with another injector and see if the problem follows the injector. If it does, you have a bad injector. If it doesn't, you have a bad cylinder. The fact that it clears off once it warms up would suggest to me that it's more likely low compression on one or more cylinders.
If it's not burning oil in any appreciable way I wouldn't fret about it too much unless you expect everything from that tractor. 1 quart in 100 hours would be moderate oil use for that engine. They shouldn't use any, but when they start getting tired, they burn about that much.... If it got to be more than that I'd be worried about broken rings, and then you shoud deal with it.

The hydraulic problem probably isn't a problem. Look at the system selector rather than the quadrant lever. You should see Draft towards the front, Position in the middle and Load Monitor to the rear. This one is probably in Load Monitor, and it will respond to every movement of the clutch since the Load Monitor is a driveline torque sensor that affects the three point hitch position.
If it doesn't work correctly in position control then you'll need to pull the lift cover and go through the linkages and probably reseal the lift cylinder while you're in there...
This is probably not the news you wanted to hear, but get a little more info and we'll figure out what you have there.

Rod

 

[RodinNS]

I didn't know there was a 7600 row crop. Thought that's what the 7700 WAS... but anyhoo. If that be so, disregard most of my post above.
That tractor certainly has an 'off' look about it too me.

Rod

 

[Fordfarmer]

Yep... 6600/7600 rowcrops in '76 only... 6700/7700 came out in '77. 66/7600 row crops were 5200/7200's with minor updates. Had a 6600 row crop for about 2 years, 6 or 7 years ago. Only minor differences from the 5200 I have now.

 

[Bob seND]

Rod, thanks for the quick reply. I purchased the tractor from a dealer in the neighboring state. The platform and seat assembly are laying behind the tractor. I don"t know about straddle vs. suspended pedals. The clutch is supported by a long spring to the trans. housing, the brakes have individual springs that were hooked to the platform. The filler neck/cap are just behind the hood seam where it says Ford. I"m afraid it doesn"t run rough long enough for me to crack an injector before it smooths out. The 3-pt. and hydraulic lift controls do seem sloppy. I"ll work on the linkages while I"m in there.
FordFarmer, I don"t think I have Dual Power. How
do I tell? There are a couple of levers on the platform I haven"t figured out yet. One back by my right heel flips side to side and is not connected to anything. One is the brake pedal lock, and a third one moves a lever on the R side of the transmission housing.
I"ll post back the serial #. My owner"s manual should be here first of next week. The "diagram
only" parts book is terrible. The I&T manual is its usual terse self. Looks like I"ll be springing for another $250 in service and parts manuals. The row crop style without a cab is what attracted me to this model, plus I didn"t want to abandon Ford from my only previous venture, a 6000 Commander. Yup, figured out what SOS stands for.
Bob seND

 

[RodinNS]

The lever on the right side of the transmission housing..... Does this go into the top of the housing?? Is there a line that runs from the hydraulic pump into this same area of the transmission housing? Is there a rocker type pedal on the platform between the clutch and brake pedals? That would be for the dual power.
The absolute give away for dual power is if the tractor will roll when it's not running and the transmission is in gear. Dual Power is a hydraulically acuated two speed clutch system, so if there's no hydraulic pressure, she'll roll away.... mabey not quick on your flat land, but QUICKLY 'here'. Keep the brakes and the brake LOCK in top shape.

The right heel pedal you have is most likely for the differential lock. You should see a corresponding lever above the hydraulic pump that this hooks to.

Personally I don't bother with the parts books for those tractors because the parts listings are easily and quickly available online at newholland.com/na in their parts section at any time, free.
I do keep the service manuals, and as you've already discovered, OEM is the only way to go. I I had a choice of only ONE of the three books/sets of books, I'd take the service manual EVERY time. Op's manuals are a good reference but there isn't much in them that you really need if you're reasonably mechanically inclined and experienced with working around tractors.

Rod

 

[Fordfarmer]

I thought it has dual power just based on the sticker on the radiator housing.. but that may just be a "Load Monitor" sticker. Seems like most have both the LM and DP, not just one, but I may be wrong. The dual power should be worked by a lever on the dash, opposite the throttle, if it's there.
The 3rd lever you mention sounds like your differential lock. Theone that's not connected to anything has me at a loss, even after going out and looking at my 5200.

 

[Gleanerguy]

Three point hiccuping is usually caused by a worn seal ring on the lift piston. As you are lifting, oil leaks past the ring, the system calls for more oil (since the lift lever is still up), it sends more oil, only to lift the arms back up again.
The only way to correct this is to replace the rubber seal ring with a new one. The new seal ring is suprisingly inexpensive, however a fairly involved job. I just replaced mine not too long ago on my 7710 with a cab. Your top cover would be easier to pull than mine, since you have no cab.