2640 hi-lo issues and clutch sticking

When I got it the main clutch didn"t work and if the hi-lo was shifted to low engine almost choked down and hydraulics squalled. After unload from trailer and stomping brakes with clutch mashed main clutch broke free. However, just moving it around lots of times clutch wouldn"t release or tractor would creep if hi-lo n Hi. Shift to Lo and clutch worked fine. I bought a 2640 that appears to have had a tough life.
Put in new load control shaft, bushing, seals, cleaned trans screen, new hyd filter, and new oil. All seemed well but while idleing in shop hyd pump loaded something terrible and engine choked down. It restarted fine but when I backed it out of the shop the clutch wouldn"t release and if the Hi-Lo was shifted to low hydraulics screamed and engine loaded however clutch would release. Shift it back to Hi and everything quiet but clutch wouldn"t work. After a few minutes of running hi-lo went back to working and clutch working. Anytime the hi-lo isn"t working the clutch doesn"t seem to work correct either. Tractor has hydraulic PTO clutch and it seems to function fine. 3 point does rattle on way up. Pump drive bushings on crank pulley are worn out or gone. Haven"t gotten that far yet to replace the drive. No leaks and everything else works fine.
Hydraulic oil had water in it, good bit of metal shavings and pump screen was about 75% clogged with slimey algea looking stuff. System primes almost instantly but pump rattles a lot thanks to coupling.
Any pointers would be appreciated or at least a clue as to why the clutch doesn"t work when hi-lo acting up. Figure there is trash scattered throughout system as nasty as oil was.

When you state metal shavings do you mean flakes or fines?? Approximately how much metal? Was sump screen crumpled? I would suggest checking hi-lo and stand by pressures. hi-lo should be 165 psi and standby 2250 psi. It's possible hyd hi-lo control valve is malfunctioning or hi side plates are warped. Foot clutch and hyd hi-lo should operate independently of each other.

Metal shavings r fine. Issue is intermittent
as if something is sticking. What is
confusing is clutch not releasing when hi-
lo is not working. They should b
independent. It acts as if it tries to shift
into low but stays in high. Both filters
we"re in good shape.

(quoted from post at 09:43:41 09/09/12) Both filters we"re in good shape.

Click to expand...

Is one of the filters you're referring to in the frt pump?? You're correct in stating that the hyd hi-lo should have zero effect on the traction clutch operation. How much metal fines were present. How long have you owned tractor and how many hrs have you put on it??????

Is there a grease fitting on the traction clutch that nobody serviced as they did not read the operator's manual? The trans filter sound like it was ignored too.
There also may have been bargain oil that was not wet clutch compatible added to the transmission.
In all honesty. Unless you have somebody like txjim, Tims or jddriver dissemble every hydraulic part to every little bit. Inspect, clean and replace broken parts. And spend over five figures.
That tractor is never going to work properly and will keep grinding a halt and needing patched up again.
Sorry but due to previous abuse and neglect. It's a basket case that is best scraped.

I paid scrap price for it but feel that was too much. It had been setting for years and trans was dry. No telling what all rusty now. Can't help but think trans screen and filter original as filter had deere on it and other filters were WIX. I have about mentally committed to a total tear down, cleaning, all new seals, n any worn parts. Tractor is low hours (3,500). Engine seems to be n great shape. Metal shavings in trans looked about right for break in if it has never been changed. The correlation between clutch sticking n power shift has to be coincidence. I expect o rings n hi-lo valve suspect. All soft parts probably suspect due to yrs of setting un used.

I replaced the hydraulic filter in right front
corner of trans. Also cleaned the suction
screen for the trans pump. Metal was
about what you might expect at first oil
change. Hour meter shows 3500. Tractor
has set many years. I wasn't aware of a
screen at the main pump. I have owned it
a few weeks and haven't put an hour on
it. Don't want to damage it worse.
Supposed it worked perfect when parked.
Course everything ran great up until it
broke and folks will stretch the truth a
tad. Any chance a bushing between the
trans input shaft and pto shaft is dry or
galled causing intermittent traction clutch
not to appear to work? There is also a
growl coming from the front of the trans
when hi-lo is n low. If n hi all is quiet.
Bad bearing, bushing, or rusty shaft? Even
new oil has turned milky with a hint or
orange. Hydraulic pto is quiet, shifts
proper, and pulls under load. I had it
hooked to Batwing mower and was about
to give it a workout when hi-lo n traction
clutch started acting up.

johndear720
I wouldn't be near as ready to send your 2640 to China as buickanddeere but buying a broken tractor has it's risks. I just think it needs some problems corrected. The traction clutch throw out brg doesn't have a grease fitting. Parts key #17 in 2nd photo is the frt pump filter(part # R27173) if tractor has a 2.4 IN.3 hyd pump. The growling noise in "low side" of hi-lo could be parts inside parts key #16 in 3rd photo.

johndear720
Do you understand how a JD closed-center hyd system functions???

It has the AR103033 2.3" pump on it.
Looks like I may split tractor for fun ;-) Is
hi-lo in direct when in hi? That would
explain lack of noise in hi.

Im not ready to send it to china yet. I see
hi hour ones selling fairly high priced and
in no better shape so someone still likes
them.

I do. Pump build max pressure n unloads. When demand for
oil drops pressure pump builds pressure again n unloads.
Whole system under constant max pressure. If I understand
system on 2640 charge pump supplies pressure for hi-lo and
pto and excess feeds to main pump.

Your closed center hyd knowledge is better than a lot of JD tractor owners. AR103033 has a filter also parts key #44. I know the hi-lo is in direct drive in one of the speeds and I think it is high speed. Would you mind divulging how much you paid for it?

Found that screen and removed it. It was
clean. Paid $3800for for tractor. Used it
about an hour mowing before lift pump
started leaking. Ran in Lo mostly. Growl
has gone away. Once in Hi, traction clutch
wouldn't release. Shifted to low and
clutch released but trans pump relief
screamed and pto dropped out. Shifted
back and forth a few times and it got
happy again and all was well till lift pump
started leaking. Im guessing it would be
worth the trouble to disassemble the hi-lo
valve and replace soft parts and spools if
worn? Still can't imagine why traction
clutch wont release but only when hi-lo
malfunctions. May need priest.

BuickandDeere, I think most of the tractors issues are from setting with no oil in trans due to bad load control seals for years in Florida"s 95% plus humidity. Its amazing how much water will condense in a transmission case down here in a years time on something that doesn"t get used enough to keep it evaporated out. Anything above the oil level tends to get rusty. Its a one owner tractor and knowing the folks it probably was fine before it was parked. Setting for 5+ years is hard on stuff. Appears engine service regular but hydrualics neglected. I"m sure I"ll be chasing sticking hydraulic valves for awhile or until I just break down and go through everything. Owner"s manual doesn"t show a lubrication point for the clutch. I"ve not located a grease fitting associated with the clutch. Luckily my labor is cheap so I won"t start parting it out just yet. At least it has ROPS, a top, good sheet metal, and weights so there are some sellable parts. ;-)

I"ve never been inside one of these particular transmissions before but I understand the concept. However, the correlation between the hi-lo acting up and the traction clutch not releasing at the same time is very odd. Was hoping someone might know how that is possible and save me a few hours labor working in the wrong spot.

(quoted from post at 22:29:34 09/09/12) Owner"s manual doesn"t show a lubrication point for the clutch.
However, the correlation between the hi-lo acting up and the traction clutch not releasing at the same time is very odd. Was hoping someone might know how that is possible and save me a few hours labor working in the wrong spot.

Click to expand...

The photo of the clutch assembly I posted confirms that there is no throw-out brg grease zert. There is no correlation between traction clutch and hyd hi-lo except traction clutch powers input shaft(parts key #20 in hi-lo photo).

I should have checked the parts book instead of assuming a
2640 has a greaseable clutch like the 1640/1840. The little
bitty iPhone screen makes for a small parts diagram.
Is there any chance of an end play issue with the high-low
affecting the dry traction clutch?

Just in case anyone is searching the archives with a similar problem I thought I would post a follow-up. Scattered the tractor all over the shop and now understand how the hi-lo unit could drive the tractor even with the main clutch released. The planetary inside the hi-lo unit was broken and had pieces floating around. Sometimes those pieces were jammed between the druma and the planetary. Since the drum is driven off the clutch plate and turns all the time the engine is running that would drive the transmission. There is now a solid input shaft in the place of the "hi-lo" internals and it will no longer cause harm or eat money. Quite of a bit of metal needed to be flushed out of the transmission housing. Almost completed with going through all the hydrualics valves cleaning, replacing, and resealing. At least I"ll know what I have when I get done. Sure would like to know what the former owner did to break the pinion planet. Virtually 1/3 of the planet housing was gone, the pin went out through the drum and was in the bottom of the case and there was a double handful of teeth and ground up metal. Amazing part is it still shifted and worked most of the time. Pretty sure the former owner knew when it broke and parked it for that reason.

The high/low hydraulic shift is handy to have. Would it have cost that much to have repaired the high/low unit?

Used hi-lo averages $2500. New aftermarket is $3800. JD new is $5,000. My unit had no usable parts. Elimination cost $200. Just wasn't $4,000 handy to me. I would have had more in it than tractor would have been worth.