Case 956XL (30K) MFD Filter & Shift Solenoid

[XL Case]

When in 2wd on the road, if you slow down/stop 4wd engages. Remains in 4wd unless you stop and renergise solenoid. At lower speed appears to remains in 2wd.

Can anyone advise on location of test ports for pressure testing the feed from the lubrication pump and the output to the dropbox?

Can the solenoid be removed for testing without removing the filter housing?

Previously corroded wiring to the solenoid has been replaced and high resistance gnd connection has been rectified.

 

[Right-arm fast]

When it goes into 4wd check voltage at the solenoid might be electrical problem

 

[XL Case]

Got back to it yesterday. 12V is present all the time at solenoide when in 2wd mode.
Obvious symptom is whine from transmission, switching on 4wd and switching back to 2wd stops the whine. Filter housing and solenoid to be removed to strip down and test further. Still to get pressure from lub pump checked. Would low restricted pressure cause drop box clutch to drag but not engage 4wd?

 

[Right-arm fast]

you could try and temporarily isolate the tractor wiring by connecting a 12v supply and a new earth (both from the starter) to the solenoid connector terminal under the cab then see if it engages 4wd as per your first post.
just a thought before you pull it to bits as I would have thought if it will disengage the clutch pack there's not too much wrong hydraulically. If it still goes into 4wd it must be a hydraulic issue.

 

[Right-arm fast]

Just wondering if you have fixed it yet?

 

[XL Case]

not yet, but progressing. Was at local show today 40mins away by road. No issue going - never slowed down. During parade around ring at idling revs, transmission warning light was coming on, off once revs increased. On return journey, warning lamp lit up when drawing up to let traffic past and again when home and slowed down to come up farm road. When transmission oil is up to working temp revs have to be above 2500, to keep pressure up and transmission warning lamp off.
Pressure test sooner rather than later, also will check filters.

 

[Zebbedee]

Yea check your filters straight away if they are clean it sounds like it needs a pump or there is a leaking pipe internally but I would guess the filters are dirty with grey sludge?

 

[XL Case]

Got back to the tractor this afternoon, tested the pressure at ports on solenoid valve.

When in 2wd mode

At start up temperature, 190 psi @ idle, rising to 325 psi at max revs on i/p test port. 167 psi @ idle, rising to 218 psi at max revs on o/p test port.
166 psi @ idle, rising to 216 psi at max revs connected to feed to drop box

Went for a run out the road to get up to operating temperature , once up to temperature dropped into 4wd when revs reduced.

Once up to operating temp, 160 psi @ idle, rising to approx 200 psi at max revs on i/p test port. 152 psi @ idle, rising to approx 191 psi at max revs on o/p test port.

Can anyone advise what should be expected from pump?

 

[case study]

This should be a bit of help,Hopefully you can see this pic.

 

[XL Case]

Most helpful. Pump is down on pressure and flow, especially when upto operating temperature (when hot no flow to lubrication cct in 2wd). Pressure switch was also found to be faulty and replaced. Pump replacement goes to top of to do list,

 

[Right-arm fast]

What engine revs does the four wheel drive re-engage at (when oil is hot)?

 

[XL Case]

Below approx 1600 revs,

 

[Gapples]

Below approx 1600 revs,

A new pump will sort it, I take you have checked/cleaned the suction strainer ?

 

[XL Case]

Yes, filter and suction strainer clear. Strip down to access pump imminent! Thanks to all for information provided.

 

[Right-arm fast]

Yes, filter and suction strainer clear. Strip down to access pump imminent! Thanks to all for information provided.

Have you fixed it yet ?

 

[XL Case]

Have you fixed it yet ?

Not yet. Started prepping to remove cab today. Pump purchased. Also need to purchase 4wd propshaft seal. Hopefully get it done next weekend.

 

[XL Case]

Last Saturday got the cab off, then washed away years of greasy mud from top of transmission. Top cover off, pump replaced & cover refitted. Plan to do the prop-shaft seal, refit cab & test this weekend.

 

[Flat 10]

well done

 

[XL Case]

Propshaft seal replaced, couple of sheared bolts replaced, cab and wheels refitted. Ran out of time to pressure test, job for another day.

 

[Hjo1]

Have exactly the same problem, did the pump change solved the problem?