I’ve got a 650G direct drive and when the transmission gets hot it won’t go in any gear at idle it has to be throttled up. I was wandering if anybody has had this problem or knows what can be wrong.
I would check transmission pressure when warmed up as compared to cold oil. The transmission oil pump may be worn. There is also a suction screen that can become clogged but usually worst with cold oil than warm oil. Is the transmission pressure light coming on instrument cluster? On top of the transmission shift valve housing there are pressure ports marked where you can install a gauge. The one for main pressure should have a pressure sending unit installed in it if has not been removed.
Number 52 is the pressure switch you can remove it and install gauge there. Gauge needs to at capable of handling 300PSI.
Thanks for the reply, I’ve not got the original gauges in it so I’ve not got no warning lights. I would like to do the pressure test, but I’ll have to get a gauge. I am just hoping it’s not a transmission problem
I thank the pressure should be 175 to 185 on direct drive units i will confirm that Monday. The transmission pump is in tandem with the hydraulic pump, so it is easy to access. Only downside to that is you have to purchase the complete assembly or find a good hydraulic rebuild shop. Please post results.
So you can’t get the trans pump off main pump and buy separate?
Looking on partscatalog.deere.com, separate sections NLA have to buy complete assembly. I don't to put you i a state of shock by telling you the price. Here is where our diagnostics needs to be accurate. I have other suggestions when we know what main pressure is.
So, do you think it could be anything internal on the transmission?
It could be but we need to run tests to verify. Check hose from suction canaster to transmission pump for loose clamps dry rot or colasped suction hose etc I am sending a picture of clogged suction screen. If you decide to remove suction screen and clean. The hose is short and stiff it helps after clamp is loose to loosen 90degree fitting at pump and twist it toward engine out of hose, hose may crack if very old.
FYI you will need to drain transmission oil to do this about 25 gallons
Ok, thank you, I will keep posted
I checked trans pump pressure it is around 175 cold at idle. I ran it for about an hour and it is around 150 at idle and when you shift it or release the brakes it drops to around 40 and stays there for about 5 secs then goes back up
Check your. de clutch pedal on left side make sure it is not binding and returning all way to stop or top of travel. What is pressure at about 1500. Do you ever remember cleaning the suction screen. I have seen this screen restrict volume of oil that pump can deliver causing this drop you saw. I know it is normal to have a pressure drop when you release the park brake system but not for five seconds. How many hours on unit?
The clutch pedal seems to fine. The hours are 5200. I just bought the dozer last year and I rebuilt the engine and I haven’t put but about 30hrs on it, so I don’t know much about the history of it. The suction screen is dated and says it was cleaned in feb 2019. The pressure is around 180 around 1500 cold and around 165 to 170 warm.
It probably isn’t hardly 5sec maybe around 2
So it is normal to drop from 150psi to 40psi when you release the brakes or shift in gear at idle?
I will have access to a manual tomorrow I know most specs are not checked at idle.
I ran it for about another hour and when you put it in gear it’s holding around 35psi and stays there and won’t move, but when you throttle it up it jumps up to around 175 and goes fine. I’m gonna drain the transmission and check screen and see what I come up with
Please post a picture of screen before cleaning it.
Can you determine what that material is in filter?
Is that normal for the filter?
It’s metal shavings, fine like plastic, and pink looking fuzz.
It’s got fine metal shavings, fine pieces of something black, and something pink that looks like fuzz
I have seen worst and still operate ok is the screen completely clogged or just in spots
It seemed to be in spots
With it being cleaned in 2019 this looks like normal except for pink. fuzz which could be shop towel material. These transmissions use a lot of lube oil and cooling oil. They flood the clutches with oil that's why there is 20-to-25-gallon capacity. This is why i suspect transmission pump is beginning to have excess wear. Let me do some more checking on specs tomorrow and i will post tomorrow. I would recommend changing the transmission filter, cut the old apart and inspect.
Still thanking about this and what i have encountered. The pink fiber is most likely shop towel fuzz. Look at filter closely they can fool you pay attention when cleaning. My friend said same thing about pink fiber. Does the transmission /hydraulic pump assembly have aluminum or cast-iron housing? Please provide SR# for your dozer. Just called a coworker i used to work with he has worked on lots of g dozers also first thing he says is transmission pump. When revved up and working does dozer spin tracks with no noticeable slippage?
I’m pretty sure it’s a cast iron housing. I’ve never noticed the trans slipping, and it will spin tracks
Looks cast to me it is rebuildable. Going to pick up a g dozer service manual shortly will get back with you. Most aluminum housing pumps were beyond repair touch housing with a magnet if it holds it is iron.
Consulted with my buddy again we suspect pump is losing its efficiency. I am sending you a picture of transmission pump assembly we suspect that thrust plate L and seal M are worn causing fluid to bypass. Deere wants $4455.44 for pump assembly. We both agree this could be original pump if machine was serviced per service schedule. That you have no way of knowing. I would drain hydraulic reservoir and remove pump assembly and take to a good reliable rebuild shop. There will still be oil draining out even though reservoirs are drained.
Looks like it would be simple to rebuild, if you could but the parts.
I looked on Deere parts page online and it lists a kit for front and rear sections separate over $700.00 a peace but does not state which pump it fits very vague on what's included in kit might want to contact a dealer. They will need machine SR# for machine and pump number. I would contact a good rebuild shop and get price quotes, for parts and how much they would charge to rebuild the pump to compare. Best to rebuild both pumps while you have removed from machine. Hydraulic side has to have some wear also.
I took trans pump apart and it is completely worn out and case is cracked.
Hello,new to the forum and need of some information regarding 1997 John Deere 650G transmission vent hose attachment location. Rodents have chewed mine off and cannot find where it needs to connect.
send serial
I believe the vent hose you are referring to is for the hydraulic tank. Iirc the hose connected at the top of the inside face of the hydraulic tank.
Thanks for reply Diesel Dave. The hydraulic tank vent is intact mostly,but easy to find. The one I am attempting to chase down one that went somewhere in the area under battery box and connected to top of transmission,I assume. Not much room to see what’s what int there. It is direct drive machine. Original was chewed into multiple pieces so no way to trace it back,found remnants of vent hose when changing hydraulic hose that was bad that goes to winch valve body.
I don’t know of any vent hose on the transmission. The original batteries had vent hoses attached to them ,maybe that’s what you are finding remnants of.
The transmission case of all "G"model dozers are a pressurized system. No vent.
The only vent hose that i remember on the G series machines was the original battery vent hose per Diesel Daves post # 41