2650 stuck in 4wd

[britcivic]

As the title says won't come out of 4wd, so checked voltage to solenoid, connected direct to battery still stuck, removed solenoid, cleaned up, spool works fine on a battery on the bench.

With no power the I can blow through the end gauze and out the right hand annular groove, with power it clicks and I can no longer blow through. Have blown compressed air through the left hand groove, doesn't seem restricted/blocked at all.

Is it common for the MFWD clutch pack to stick?

 

[Michael S]

I don't know much about JDs but would presume that the 4WD is powered out and sprung into 4WD like most other makes, is that any help?

 

[britcivic]

Yes it's powered out, sprung in as you say. I'm hoping the problem is something simple that I've overlooked.....

 

[Phil P]

If your sure the solenoid is ok it would be a good idea to put a gauge on and check for any internal leakage.

Has it just stopped disengaging all of a sudden or have you only just noticed? There’s a steel band that goes around the clutch pack, the piston pushes on the band to disengage the clutch but the band can ware down over time then the clutch stops disengaging properly.

 

[britcivic]

The tractor came to me like this 'ready for work, nothing needs doing on it' !!
6800 hrs on it and from the state of the link arms and hitch I'd say probably genuine.

Would the MFWD clutch wear out in this time?? My others JD's have 9000 and 13000 hrs and 4wd working fine.....

 

[An Gof]

Check the brake lights and fuses

 

[BlueBrick81]

Had the same on our 3050. the clutch drops out the bottom easily enough and our local JD dealer rebuilt the clutch pack for not alot of money £150 if i remember correctly.

 

[Phil P]

The tractor came to me like this 'ready for work, nothing needs doing on it' !!
6800 hrs on it and from the state of the link arms and hitch I'd say probably genuine.

Would the MFWD clutch wear out in this time?? My others JD's have 9000 and 13000 hrs and 4wd working fine.....

Some seem to last forever, some don’t

 

[britcivic]

I botched a pressure test on the test port tonight, my crappy compressor gauge with a bit of PTFE tape round the threads read 100-120psi ish - does that sound close to spec?

 

[Phil P]

I botched a pressure test on the test port tonight, my crappy compressor gauge with a bit of PTFE tape round the threads read 100-120psi ish - does that sound close to spec?

Bit on the low side, if I remember right system pressure should be around 25bar/362psi tested at the top cover.
Ideally best way to test for leaks is to but a gauge lube pressure which is test on the feed pipe on top of the main hydraulic pump. Should be around 6bar. If lube pressure drops and doesn’t recover when you disengage the mfwd it means there’s a leak. Could check the hi/lo also while the gauge is on.

 

[Tractortech]

Now Then..
System pressure for yon is 10.5 bar (155 psi).
I'd drain the oil, MFWD shaft off, bottom cover plate off, pull the MFWD output shaft out the front while some burly assistant holds/catches the MFWD clutch. Then remove the aluminium cover, there's a ring around the clutch which wears a step in and won't be able to release the plates when pressure is applied to the piston.
A simple but oily job..
Item 21 below, eh

 

[britcivic]

So I've started on pulling the MFWD clutch pack - drained oil, cleaned intake screen (some swarf there but I've seen similar before) transmission filter was made in 2005, and return filter looks of similar vintage.

Dropped the sump off the MFWD, and found a lot of shrapnel there, a folded piece of thin metal, a top hat shaped piece (about 5mm dia.) and a small rod (about 3mm dia.) with a square end. Does anyone recognise these? -I'm hoping they're related to a past (repaired) problem, as most things seems to be working ok, apart from the 4wd, obviously....

 

[Phil P]

So I've started on pulling the MFWD clutch pack - drained oil, cleaned intake screen (some swarf there but I've seen similar before) transmission filter was made in 2005, and return filter looks of similar vintage.

Dropped the sump off the MFWD, and found a lot of shrapnel there, a folded piece of thin metal, a top hat shaped piece (about 5mm dia.) and a small rod (about 3mm dia.) with a square end. Does anyone recognise these? -I'm hoping they're related to a past (repaired) problem, as most things seems to be working ok, apart from the 4wd, obviously....

I have a feeling the debris, top hat and bolt looking bit are from the handbrake band. He folded bit of tin looks like a shim, could be from anywhere , although I have a feeling it maybe of the pto reduction gears in the back housing.

 

[britcivic]

Thanks for that- might make some sense when you look at what I was just about to post:

Well, when I say everything seems to be working ok, it's very clunky through the gears (synchro's seem ok though), and the handbrake is sometimes weak as, sometimes strong, and sometimes the lever springs back towards you when you try and release it, - won't go back until you set off.....

So handbrake band could have a looses /missing segment??

The chunks of cast are a bit worrying too, althought the pile in the corner looks like it might have been there a while... (any thoughts on where they could come from?)

This tractor's starting to look more like a project and less like a bargain...

 

[Phil P]

Thanks for that- might make some sense when you look at what I was just about to post:

Well, when I say everything seems to be working ok, it's very clunky through the gears (synchro's seem ok though), and the handbrake is sometimes weak as, sometimes strong, and sometimes the lever springs back towards you when you try and release it, - won't go back until you set off.....

So handbrake band could have a looses /missing segment??

The chunks of cast are a bit worrying too, althought the pile in the corner looks like it might have been there a while... (any thoughts on where they could come from?)

This tractor's starting to look more like a project and less like a bargain...

It’s hard to say on where the cast is from, you say the gears where clunky did it go in all gears without jumping out? 50 series can break the casting In the diff housing around the top shaft but you generally lose some gears when that happens.

As you say it looks more like a project! Couple of days and you could have the cab off, spill it’s guts out and go right through it, re seal everything etc. You’d know you have a good reliable machine then

 

[njneer]

Are the chunks definately cast as they may be chunks of the handbrake band it is quite a chunky affair on these not a flat type on more modern machines . The other bits could definately be from the handbrake band mechanism .
on the top of the back end of the tractor is a screw in plug where you can get in to adjust the handbrake band with a large flat screw driver , you may be able to get a small bore scope in there and have a look .

 

[britcivic]

Think you're right - thought they were cast because they're magnetic, but after a second look they're not very magnetic and I can scrape them back flat with a pocket knife pretty easily. Handbrake looking suspicious...

Here's a (slightly) better photo of the top hat piece.

Are the rivets hollow on the brake band? My first thought was it looks like it might be to retain a spring in a check valve of some sort?

 

[britcivic]

I'll try to get time to drop the clutch pack today, and order a cheepo endoscope....are they any good?

Then after lambing I'll have to take the plunge....

Couple of days and you could have the cab off, spill it’s guts out and go right through it, re seal everything etc. You’d know you have a good reliable machine then
T

If it goes as smooth as you make that sound I'll quite enjoy it..............

(sorry Phil P, only just spotted your reply!)

 

[britcivic]

Well, between other things I managed to drop the MFWD clutch (right hand had to take the place of the burly assistant mind!). There is a definite step worn on the band, part 21 - so I'll replace that.

Whilst I'm at it should I replace the two O rings on the shaft?

Also the o ring at the top of the pressure pipe looks a bit skewed to me:

I take it I just pull the pipe down out of the bottom to change this?

 

[Phil P]

Well, between other things I managed to drop the MFWD clutch (right hand had to take the place of the burly assistant mind!). There is a definite step worn on the band, part 21 - so I'll replace that.

Whilst I'm at it should I replace the two O rings on the shaft?

Also the o ring at the top of the pressure pipe looks a bit skewed to me:

I take it I just pull the pipe down out of the bottom to change this?

Definitely replace the O-rings on the shaft they look very flat. Put plenty of grease on them so they don’t get nipped putting it back in. The pipe shop just pull down as you say and there will be a small O-ring sat in a recess inside the hi/lo housing. I’d get genuine O-rings as they’re only pence and an odd size to try and match.

You’ll need a press to separate the clutch and re seal the clutch piston. When it’s going back together sit the splined gear back in to align the plates and also drop the shaft into get everything Centrel. Press it back together and then check the shaft slips through easily again otherwise you’ll end up damaging the O-rings when it goes back in.