|
|
| Hi, I'm trying to figure out a hydraulic problem on a John Deere 4630 tractor powershift. With about 10000 hrs.
I have low transmission lube pressure. At 2000rpm and 100 degree oil. 20 psi.
Clutch psi is 170
It takes about 30 seconds for oil to come to after starting tractor.
Psi is ok with cold oil but slowly gets worse as it warms up. With warm oil I have to keep rpms up or else I will loose all hydraulics, no clutch, no shifting, no brakes, no steering.
I have replaced filters and suction screen. With no obvious issues.
I have destroked main pump and lube psi is still low.
I have looked in plug hole at rear of transmission no oil is spraying around in there except a small drip every second towards the right edge of the hole. Seems to be normal.
Pto engagement and shifting through all gears , brakes, and diff lock, and clutch does no change to lube psi.
I am wondering were this oil is going. Or were possible pressure could be going.
If I press clutch pedal should there be or not be, any lube psi change.
Thanks for your time and advice. |
|
| |
|
Minot ND | push clutch in, check lube pres, engauge pto, see if lube changes at any time on ether. |
|
| |
|
| When I push clutch in no change in psi.
When I release clutch , psi will briefly drop then come back to previous psi.
Pto will briefly drop lube psi upon engagement. Then return to previous psi. When disengaged no change in psi |
|
| |
|
Pickens | ...keep rpms up or else I will loose lose all hydraulics, no clutch, no shifting, no brakes, no steering...<<
Isn't this a dead give away for a bad transmission supply pump? located in the front pump of the powershift?
OR, restricted intake (filters), bad/leaking o-ring on the pickup? these type things...?
Or is it too hot here today, I don't know these things like I think I do?? Lol
Good Luck,
CF |
|
| |
|
southern Jasper County,In | I own 6 4630 powershifts and the front pump in trans supplies oil to main hyd pump in the front of tractor.If you have taken out suction screen and cleaned it with new filters installed and it does what you are describing it propably needs a new trans pump. |
|
| |
|
Pickens | You know, you have kinda validated a point of mine "here"...
I always said, if I were to move to a furrin' country (Southern, for OverSeas), I could farm the countryside with a fleet of 4630s/4840s and 8820's..., and put a few coins in the Bank!
CF |
|
| |
|
east central Nebraska | Sounds to me like a loss of oil somewhere in the system more than a bad pump. High pressure leak to sump from the scvs or rockshaft control valve or could be cooler relief, filter relief valve stuck open. I've also had a blown gasket in the valve body on the left side cause that issue. |
|
| |
|
Fruita CO | As others have said, your transmission pump is worn out. Loss of all functions when hot & idled down, 10k hours, classic.
Edited by ronm 6/19/2018 19:27
|
|
| |
|
SE MT | CornFed13 - 6/19/2018 18:33
You know, you have kinda validated a point of mine "here"...
I always said, if I were to move to a furrin' country (Southern, for OverSeas), I could farm the countryside with a fleet of 4630s/4840s and 8820's..., and put a few coins in the Bank!
CF
Looking to add another to our fleet as well.... I guess there's a reason so many are still around after 40 years and still being used regularly. |
|
| |
|
| Has anyone replaced a transmission lube pump and it solved their problems. My Deere dealer says they never have replaced one. Usually it's something else. |
|
| |
|
NW Illinois Stephenson county | Did this happen suddenly or progress slowly? 20 years ago I was talking to someone while my JD4020 with syncro-range which was running go suddenly quiet and have hydraulics only when the tractor was revved wide open. The mechanic said the pipe was broken off the charge pump in the transmission. At least that is how I understood it. I think that is the correct area to look at. Good luck! |
|
| |
|
Fruita CO | What exactly are you calling a transmission lube pump? An 8-speed PS has one trans pump, It supplies pressure to operate the transmission, lube the transmission, & charge the main hyd. pump. When it's worn out, nothing works. And when a tractor gets 10K hrs, it's pretty likely it's worn. Your dealer has not worked on many PS transmissions if they have never replaced one, it's part of the front clutch pack. |
|
| |
|
SE MT | Dieseldirt - 6/19/2018 23:52
Has anyone replaced a transmission lube pump and it solved their problems. My Deere dealer says they never have replaced one. Usually it's something else.
Slightly different situation, but our 4630 with the Quad Range had similar problems to yours
When hot the Hydraulics would barely work, not at all at idle when hot. PTO lever would kick out hot, and clutch was more jumpy (if that's even possible on a quad range), and the brakes were non existant unless you had the engine revved up.
PTO and clutch pressures were within specs when revved up hot or on cold oil, but when at mid range rpms or near idle they had dropped off 50 psi or more.
Only difference being that when I checked the screen it was full of brake material. Previous owner had a brake failure and then sold the tractor.
My 16K powershift 4630 has seen a brake failure, but I think we got it pulled apart in time... No trans pump yet.
Trans pump is what I'd lean towards even though it's possible a pipe could have broken inside or blown an o ring.... things happen after 40 years. |
|
| |
|
| Yea I'm referring to the only trans pump.
I wanted to make sure people wouldn't say it's this gasket or that oring is common failure on that tractor. Before i buy a 3000 plus dollar part
Edited by Dieseldirt 6/20/2018 08:30
|
|
| |
|
Fruita CO | Does your dealer have a flow meter? They could run a trans pump test if you want to be sure.
A reman front pack would be the way to go, with those hours, the C1 & C2 clutches will probably be ready for some attention too. |
|
| |
|
SE MT | Dieseldirt - 6/19/2018 14:45
Hi, I'm trying to figure out a hydraulic problem on a John Deere 4630 tractor powershift. With about 10000 hrs.
I have low transmission lube pressure. At 2000rpm and 100 degree oil. 20 psi.
Clutch psi is 170
It takes about 30 seconds for oil to come to after starting tractor.
Psi is ok with cold oil but slowly gets worse as it warms up. With warm oil I have to keep rpms up or else I will loose all hydraulics, no clutch, no shifting, no brakes, no steering.
I have replaced filters and suction screen. With no obvious issues.
I have destroked main pump and lube psi is still low.
I have looked in plug hole at rear of transmission no oil is spraying around in there except a small drip every second towards the right edge of the hole. Seems to be normal.
Pto engagement and shifting through all gears , brakes, and diff lock, and clutch does no change to lube psi.
I am wondering were this oil is going. Or were possible pressure could be going.
If I press clutch pedal should there be or not be, any lube psi change.
Thanks for your time and advice.
Here's some oil flow pics and maybe some descriptions. Wondering if "F" (oil press reg. valve) or "E" Relief valve should be checked along with their springs? Maybe one is broken or stuck?
Not a hydraulic expert, but I'd start with the stuff I can check before I tore the trans pump out especially if it was working ok before.
*EDIT* Tech manual says for low lube pressure check for blown pedal valve and pressure reg. valve housing gasket.... otherwise check for bad trans pump best of luck.
Edited by dieselfume1 6/20/2018 08:59
 (img004 (full).jpg)
 (img005 (full).jpg)
 (img006 (full).jpg)
Attachments
----------------
 img004 (full).jpg (191KB - 174 downloads)
img005 (full).jpg (232KB - 154 downloads)
img006 (full).jpg (272KB - 146 downloads)
|
|
| |
|
| I bought it this way. And used it one season. And it seems to be slightly worse after one season of baleing |
|
| |
|
| Thanks |
|
| |
|
Fruita CO | Wouldn't hurt to check those valves. But if F was stuck or broken, the trans wouldn't work at all. He said has 170 psi cold, that's what that valve does. |
|
| |
|
Pickens | I agree with Ron^^^
Any front pump application such as Deere's or the automatics, (GM, Ford, Mopar) with a gear set, it only takes three to five thousandths in wear clearance to make the pump weak, very weak.
My vote is still the pump,
CF |
|
| |
|
SE MT | ronm - 6/20/2018 13:49
Wouldn't hurt to check those valves. But if F was stuck or broken, the trans wouldn't work at all. He said has 170 psi cold, that's what that valve does.
I see what you're saying Ron, That does make sense. |
|
| |
|
| Tore tractor a part and there is. 040 wear in side of gears on pump. I'm replacing clutch pack and pump. I'll let you know if it solved it. I think it will. Valve bodies and suction pipe were good
Edited by Dieseldirt 6/25/2018 13:57
|
|
| |
|
Fruita CO | Glad you found it, sometimes it's hard to make the decision to tear into it, but you just have to grit your teeth & jump in... |
|
| |
|
| Problem solved bad pump. Tractor is working well |
|
| |
John Deere 4630 powershift hydraulic problem
