The Forestry Forum

General Forestry => Forestry and Logging => Topic started by: albionlogger on April 19, 2019, 04:19:53 PM

Title: John deer 640D tranny fluid issues
Post by: albionlogger on April 19, 2019, 04:19:53 PM
Hey everyone,so i'm having a transmission fluid level issue in my jd 640D skidder. I acquired the skidder about a year ago, when i bought it all fluid levels were up to spec. Ran it all last season and they continued to stay that way until i got to my last job of the season.Pulled out the dipstick for the tranny and it barley read on the dipstick, just the first 1/4 inch showed fluid. Couldn't find any leaks anywhere and being in the middle of a job i didn't have time to investigate it much. so i picked up a pail of jd hygaurd, topped it off (about 2 gallons)and ran it for the remainder of the job checked it at the end of the job and it read over full. Fast forward to last week and i was servicing it getting it ready for this season. The tranny of course still read overfull and decided i would just change it out and refill it with fresh fluid up to spec. I read my manual and it said tranny capacity was 9 gallons this was also confirmed by the spec sticker on the inside of the engine compartment door,so i picked up 2 five gallon pails of jd hygaurd put 5 in and the level was already half way up in between add and full. I decided id run the machine through the gears for a sec and then give the 5 min the manual specs to wait before checking it, still the level didn't budge.I know over full can be just as bad as under full so i kind of split the difference and just put in a couple extra(or maybe not)gallons till i can figure out what is going on.Also through all of this the tranny has shifted and pulled 100% fine. no mechanical issues at all.any help you guys could give me would be greatly appreciated! thanks in advance!Alex
Title: Re: John deer 640D tranny fluid issues
Post by: Oliver05262 on April 19, 2019, 10:14:59 PM
  There might be a sticker on the bottom of the access cover to the tranny dipstick (I know there is/was one on the 640D. Can't remember the exact wording, but you're supposed to wait (??) minutes after shutdown before you check the oil level. I'll be near my customer's skidder this week and I'll write the instructions down. 
Title: Re: John deer 640D tranny fluid issues
Post by: albionlogger on April 19, 2019, 11:54:44 PM
Thanks for the reply! ya i have that sticker and it says to wait 5 minutes and i do every time i check it.This issue could be completely harmless but its driving me nuts!The dipstick shouldn't lie but then again neither should the service manual.Could it be a valve issue??Although again the tranny functions perfectly
Title: Re: John deer 640D tranny fluid issues
Post by: dnash on April 20, 2019, 07:50:57 AM
Did you fill the winch when you changed the transmission oil? If you have a service manual, it lists the steps you need to do.