Case 895 MFWD solenoid

[btlacount]

Hello
I recently bought a case 895 mfwd with the electric switch TA.
Im assuming it's a 94.
when I got the tractor it had no power to the cab and switches.
I have recently restored all the power to the cab and all the switches( bad connections in 12v power to ignition)
My 4x4 does not engage. I verified that I have 12 volt power all the way from the switch down to the solenoid. I dont know where to go from this point. Before I pull the solenoid out is there anything I should check or do prior to this? I see that it is a hydraulic engaged solenoid so im wondering if I have a hydraulic problem. it seems to have a power steering issue, Could this be related to the mfwd? Can someone who has worked on these help me out please? Thanks guys

 

[btlacount]

that is a picture of the solenoid.

Should I be able to see something move through the holes when I apply the 12v power to it?

I can hear a click but I dont see anything close the holes. any advice would be great.

 

[MARK ROBKE]

Maybe use a rubber tipped blow gun and see where the air flows energized and un-energized. Mark.

 

[wore out]

''my MFWD does not engage''

Many/most of these systems work the opposite of what you might think, MFWD is engaged by spring(s) acting to engage the wet clutch pack when there's NO power to the solenoid and NO oil pressure to the clutch piston.

When power is applied to the solenoid, oil pressure is then applied to the clutch piston which overcomes the spring pressure and DISENGAGES the clutch.

So an electrical failure will ENGAGE the MFWD clutch.

I am NOT absolutely sure your specific tractor works that way, but looking at the parts catalog it appears that it DOES.

Try disconnecting the wires from the MFWD solenoid and see if MFWD then engages.

If NOT, likely so have some sort of mechanical failure in the system, could be the MFWD clutch unit itself, driveshaft splines, the front ring and pinion, the front differential, or the individual driveshafts and planetaries at each wheel.

Try this, with the engine NOT running jack up one of the front wheels enough to turn it and note if the driveshaft turns coming from the MFWD dropbox/clutch unit and if there's any unusual noises.

The MFWD clutch should be engaged, locking the drives to the front and rear wheels together and you should NOT be able to turn the jacked up front wheel.

On the chance that the MFWD clutch on your tractor is NOT set up as I described disregard the above!

 

[btlacount]

Ok thank you for the information. Id like to confirm that
my tractor does operate In that way. When I first realized
the MFWD was not working there was no power to the
solenoid. I since then restored the power to the solenoid.
So if it does operate as you describe I should have had
the MFWD engaging when it had no power. I removed the
solenoid. Cleaned it good as I could with some carb
cleaner. The solenoid seems to make more movement
now after cleaning it. I tested it on the bench, when I did I
put some hy-tran fluid on the very tip of the screen of
the solenoid with the solenoid standing upright causing
the fluid to puddle on the tip. When I put power to the
solenoid it sucked the fluid in, so Im assuming its
working. I then replaced the 3 ORings on the solenoid
after I cleaned it. I removed the driveshaft cover so I can
have someone drive it and I will be able to see if its
operating the shaft, and possibly have issues somewhere
else like you stated. My driveway is glare ice right now so
its pretty easy to break the rear tires free on an incline,
easy to tell that the 4x4 is not working.



Can anybody else verify that the case 895 operates as
wore out described above?



I will respond with any updates and thanks for the input

 

[wore out]

''I removed the driveshaft cover so I can
have someone drive it and I will be able to see if its
operating the shaft''

That MAY not help much to narrow down the cause.

If something has failed in the clutch area the driveshaft will be turning because of the front axle ''backfeeding'' power to the driveshaft.

If something has failed in the front axle the driveshaft will be turning because of power through the MFWD dropbox and MFWD clutch.

I think you will learn more by jacking up a front wheel and trying to turn it, as I previously wrote.

 

[btlacount]

In reply to :

If something has failed in the clutch area the driveshaft will be turning because of the front axle ''backfeeding'' power to the driveshaft.

If something has failed in the front axle the driveshaft will be turning because of power through the MFWD dropbox and MFWD clutch.

I think you will learn more by jacking up a front wheel and trying to turn it, as I previously wrote.





I just drove it and witnessed what you're pointing out. Driveshaft is spinning but still no 4 wheel drive. So in theory when everything is working on a 4x4 tractor and it's in 2wd the driveshaft still rotates bc it is solid with the front drivetrain. Thank you for pointing that out. That makes sense now. I was thinking about it wrong. Now to the front tire advice....

I guess I still dont follow why lifting a tire off the ground would make a difference. If something is broken up front, then one tire will rotate freely? If thats the case how do I know whats broken?

wouldn't I be better off disconnecting the driveshaft and checking to see if the rear spline shaft is rotating while being driven? That way I would know the rear is driving the driveshaft?

could you explain the theory behind the front tire test? Thanks for the input !

 

[btlacount]

I still need to figure out if the case 895 should be engaged in 4wd with a faulty solenoid. when the solenoid is operating properly and you put power to the solenoid does the solenoid disengage the 4wd? or does it do the opposite and engage the 4wd? does anyone know? I need to narrow this part down please and Thanks

 

[Jim Becker]

(quoted from post at 17:18:36 02/19/23)
. . . wouldn't I be better off disconnecting the driveshaft and checking to see if the rear spline shaft is rotating while being driven? That way I would know the rear is driving the driveshaft? . . .

I know absolutely nothing about the specifics of this model tractor. However, I think it is possible that even if the rear spline shaft is not being properly driven by the drive train, with no load it may turn giving the appearance that it is properly driven.

 

[wore out]

Jacking up a front wheel is a VERY simple thing to try requiring no tools other than a jack and a few blocks and NO disassembly.

If the driveshaft turns it will indicate FOR SURE that everything ahead of the MFWD dropbox/clutch is operating.

One other thing, typically there would be a pressure test port near the solenoid to check pressure in the ''clutch release'' circuit as the solenoid is energized ir deactivated. One would need to know what pressure we are looking for and use an appropriate gauge.

I'm still betting the clutch DISENGAGES when power is applied to the solenoid sending pressurized oil to it.

 

[btlacount]

Wouldnt you need to Jack up both tires?
I just dont understand how the axles are driven up front.
So your saying one tire on the ground and one in the air you can spin the lifted tire and it will turn the driveshaft while the other tire is stationary? The front has the ability to do that? I will give that a try! Thanks

 

[wore out]

Yes, jacking up only one front wheel will work as it has an ''open differential''.

 

[wore out]

Any news to report on the MFWD problem?

I did a little more digging which SEEMS to confirm my thoughts that the MFWD clutch is spring-engaged and hydraulically released.

 

[btlacount]

I have not been able to work on the tractor the past week.
I put everything back together I had apart for the
electrical overhaul I was doing while diagnosing mfwd
issue. I still need to Jack up the front tire and see if it spins the driveshaft.

I have been trying to find a local mechanic that might be
able to help me tear into the tractor.

Do you know what type of failure could be happening if it is in the rear and not the front differential? Will I be
splitting the tractor to fix it you think?

 

[btlacount]

Im hoping Its something fairly simple and I can just drop the cover to the drop box I believe you called it previously. Any thoughts on what the procedure might involve to diagnose and repair an issue in that location?

 

[wore out]

(quoted from post at 18:06:44 02/27/23) Im hoping Its something fairly simple and I can just drop the cover to the drop box I believe you called it previously. Any thoughts on what the procedure might involve to diagnose and repair an issue in that location?

If jacking up a front tire and turning it (may take quite a bit of effort) results in the driveshaft turning that would mean the MFWD clutch is slipping.

The clutch is engaged by a cone-shaped spring (which could be broken) or the lined plates could be worn thin, or perhaps a snap ring could have come out of place, but all that can be seen after draining the oil and removing the ''dropbox''.

If you can't turn the jacked up wheel you might try turning the driveshaft itself with a bar or pipewrench, if the clutch is simply worn and slipping what seems hard to turn by hand may not pass enough torque to drive the front axle with enough power to make it seem like it is doing it's job and pulling it's share of the load.

 

[btlacount]

Ok thank you for the info. I need to get back to working on it. With the information you have provided I feel better about getting it fixed. The tractor I have seems to be a good machine. It runs good just need to get that 4x4 working.I will update you as soon as I get more figured out. Here is a image of the tractor

 

[btlacount]

Well this is what I have discovered after jacking up a tire.

Collar on the driveshaft and pinion shaft is stripped on
the driveshaft.

Pulled the driveshaft off and verified the collar is worn
down smooth. Im hoping that this will be the end of this
once I get a new collar. Thanks Wore Out for the help so
far! Im learning a lot.