699 Front Differential Choices

I have experienced some issues with the 699 NoSpin front differential. I took it all apart and only saw what I felt was minimal wear on the NoSpin differential assembly. I am concerned that perhaps as a Loader Tractor the NoSpin may not be appropriate.
1. Has anyone else had good or bad experience with the NoSpin differential as a front differential on a 4WD farm tractor?
2. Was the 699 offered with a normal spider differential, parts book online does not show it, Service Manual shows one?
3. Does any other AGCO tractor use the same front 4wd axle and differential as the MF699 in case I need parts?
Thanks, Paul

The no-spin or LSD in the 600 series was not prone to any more problems than different configurations of differentials in any other models, that I am aware of.
Having said that, any model with a front end loader has to be balanced correctly, or premature failure of the front axle is likely. By that I mean that a counterweight should be fitted to the rear linkage or "hitch" while using the loader. The rule of thumb is that the available power to the traction wheels should be divided 30% on the front wheels and 70% on the rear. A rear counterweight is advantageous for keeping the rear wheels on the ground and keeping that ratio in check. The moment the rear wheels "lift" because of extreme weight being applied with the loader, you are placing in excess of 30% of available power on the front axle drive train. Repeated overloading situations like this will eventually cause a failure at the front axles weakest point.
I believe that possibly the same axle beam was used in the 698 as well as the MF 298 model.
Can I ask what problems you are experiencing?
regards, Evan.

Thanks Evan for your reply. I took four pictures today but only two transferred so far from my iPhone. They are attached. I will attach the others later.
The tractor belongs to my friend, he just purchased it from the prior owner. The four wheel drive worked fine but after pushing into the manure pile 3 times it quite working. He followed that up with pushing into a gravel pile, still not working. At the time we did not know it was a No Spin differential (Also called a Detroit Locker). We were advised to jack up one wheel and run a simple test. In one direction we heard loud clunking, in the other very muted clicking. We were advised to pull the drop box (see in picture) but to do that you have to pull the differential and to do that you have to pull the axles/planetaries. Anyway, this was new to us but we did it. Pulling the King Pins was a real treat until we learned the trick. The No Spin differential looked fine to me, only some minor wear on the teeth edges. I took it to the local MF shop, the Service Manager also agreed it looked OK. By the way, we do have the Service Manuals.
We thought about replacing those parts that had minor wear only to find out MF no longer offers those parts, big disappointment. Anyway, we decided to put it all back together and gain more experience. It should work as I put it together in the locked position.
Evan, your comments about how much weight and pull get put on those front tires with a loader seem right to me. I am thinking when the tractor was pushed into the manure pile likely with a little lifting action it put to much traction on the No Spin clutches and they disengaged simultaneously. That is my theory so far. And of course a minor amount of wear will only make it worse.
On further examination it seems this tractor has had a lot of loader work, likely heavy. The Allied (brand name) loader is welded at all the pin mounting points, this we observed before purchase. The weld repairs on this were well done, and my own observation about second tier loader manufacturers is they use poorer steel. So that was not a big flag. What we did not observe is the left front lug bolts appear to have been run loose and the mounting clamps to the wheel rim had all been re-welded, some poorly. Who ever put the left tire back on used English fine thread lug bolts rather than the required Metric lug bolts. They just "aired" it in and screwed up the threads. I had to use a 4 ft pipe to get them out, all the way.
It also appears work had been done on he King Pins and the bores they go into. Some were badly grooved. From right to left they did not match diameter, they should have. I found out later the entire front axle was for an earlier serial number tractor, so it does not appear have been the original axle, King Pins, Planetaries, etc.
Rather than lug bolts I plan to screw metric bolts in from the back side using the damaged threads (I ran a tap through them to repair) putting lug nuts on the front. Right now I am waiting for 16mm x 1.5 mm lug nuts from North Carolina, I am in WI and it seems this size is not readily available around here.
So a little long but this is my tale. If we continue to have issues I have thought about trying to find a normal spider differential, so one wheel can spin.
I would appreciate any further thoughts.
Thanks, Paul

More Pictures as promised. Thanks, Paul

From what you have explained to me here, you have a problem with the "no spin" front differential, doing just that...no spin? Are you actually getting any wheel spin on the front wheels, at the same time as you are getting wheel spin at the rear wheels?

From your pics, you have disassembled the front axle and found no fatigue in any of the components. Could I suggest that the drive TO the front axle may possibly be the problem. Remember that drive to the front wheels is controlled by energizing a hydraulic clutch pack. You could either have a push button switch that activates a solenoid, which, in turn activates a control valve which diverts oil under pressure to the 4wd clutch pack, or in some models...... and I can only vouch for models supplied to the Australian market...... have a simple "knob", which is a push-pull type, to divert oil pressure to the clutch pack in question.
Is this clutch pack energizing in the first place? If it is, could it possibly be "slipping" under load?

I would go back to the beginning and test for correct energizing of the clutch. If your machine has electric over hydraulic, test the switch and/or solenoid first. If you are satisfied that you have oil flow to the pack, set a pressure gauge "in-line" to the pack, and check the pressure. For memory, it should be approximately 220 to 280 PSI. If this checks out, the problem may rest with the clutch pack itself.
Worn or blown "o" ring seals on the piston or burnt and/or warped discs may be causing the slippage.
Let us know what you come up with,
regards, Evan.

There is a button on the dash that seems to have a mechanical latch. I got involved after my friend started to disassemble the drop box.

We did run a test on the transfer case clutch function (drive shaft NOT connected to front axle.):
1. with tractor not running the drive shaft spins freely by hand.
2. with the tractor running but the 4wd NOT engaged, the drive shaft spins freely by hand.
3. with the tractor running and the 4wd engaged the drive shaft rotated about 1/4 to 1/2 turn by hand and then seems to hit a stop. The free rotation up to a point was interesting in that it seemed too much for gear backlash.
We also ran a test by jacking up one rear wheel and engaged the 4wd. The drive shaft turned, counter clockwise. I needed direction so I could put the ring gear in correctly. The pictures showed one orientation, the text described another. The text was correct.
Your comment about transfer case clutch slippage is interesting. We will be checking that first if we continue to have issues. My son has gauges we could use so I will do that when he is home. I did notice there is a test for that in the service manual. Right now I am waiting (7-10 days) for the 16mm x 1.5 mm lug nuts.
Thanks again, Paul