GT 235 Tranny overflowing

[jsach]

My GT235 transmission is pushing fluid out of the filler cap opening during operation.
I have changed the fluid and I NEVER over fill. I check it cold and never fill it much above the add line.
Have also tightened the clamps on the hoses which connect the plastic resevoir to the tranny, no leaks there.
I add about half a quart ever time i mow because of the fluid lost from overflow.
By the way, the tranny is working fine other than the overflow.
Anyone had this problem and what was the fix?

Thanks

 

[glc24]

Hello jsach and :welcome: to TBN

There has to be a vent somewhere that is plugged or blocked by something.

Greg

 

[jsach]

Greg, plugged vent was my first thought, but, if there IS a vent, I sure can't find it. About to jack it up and look again. Will let you know if/when I solve this thing.

 

[bullbreaker]

Greg, plugged vent was my first thought, but, if there IS a vent, I sure can't find it. About to jack it up and look again. Will let you know if/when I solve this thing.

Watching this thread closely I have developed same issue w/my GT235 (400+ hrs). Be careful if looking around that area w/tractor running you don't damage transmission cooling fan or get finger whacked on it. Haven't had time to look at mine.

Boone

 

[glc24]

Hmm,did some checking and it seems that trans is a sealed deal. jsach,did you just change the fluid when this problem started,and were you able to get the recommended fluid amount in the trans? It may be possible there is an air bubble.

I found this:

OK, guys, here's the scoop - J-D's manual # OMM148971-I2 gives the procedure for changing the transmission fluid by the owner. On page 34, it says "do not remove sealed black cap ｩ. Fill only at reservoir bottle". This suggests that, for some reason, it's "sealed", and I'll be in a "heapa trubble" if I do something to it. On my GT235, it's a black threaded cap on the left rear (looking forward) of the transmission. It's oriented vertically, and removes upward. Another conversation with the dealer and his mechanics suggests that it's OK to crack this threaded cap (don't remove it) - just back off a half turn, or one turn - and it'll vent the air bubble. Which is what I did as soon as I got home, and lo and behold, the air bubble vented as expected, and the level of fluid in the small plastic fluid reservoir drained into the transmission's casing. I was able to get all 4.6 quarts in, it filled up like it was supposed to. After snugging up the sealed black cap (C in the picture), and replacing the filter and fill cap (on the plastic fill reservoir - D in the picture), it works like a charm. Everybody's happy. I would expect John Deere to be a little more accurate in its description of the correct procedure.

Greg

 

[jsach]

Thanks guys. We may be onto something. The tranny is always slow to vent when I change or add fluid (major design flay in my opiion). However, I watched closely when I changed it recently and air continued to bubble up through the fluid in the resevoir bottle until it finally stopped and I assumed that it was completely vented and then I just put in more fluid to bring it about half way between add and full.
Did it take the full 4.6 qts (or whatever the capacity is)? Not sure but likely not. I was using gallon jugs and didn't watch how much went in. Just figured that "full is full". Maybe not that simple.
I'm headed back out to try loosening the DON'T TOUCH black cap.
Question: Did you retighten the DON'T TOUCH cap after you filled the tranny?
Thanks again,
Jim

 

[jsach]

Greg, I'm awake now. Just realized that you were quoting someone else so disregard my question about retightening the DON'T TOUCH cap.

 

[jsach]

Greg/Bullbreaker, problem solved. Thanks much.

Bullbreaker, here's the deal: I opened the "DON'T TOUCH" cap maybe two full turns then slowly added fluid. I started seeing air bubbles around the "DON'T TOUCH" cap. Even when it is venting through that cap, it is still VERY slow to take fluid. I filled the resevoir to the full mark at least three times, waited several minutes and checked again. Three times the fluid level had dropped well below add. I added more and waited again.

After the 3d or 4th cycle it finally quit dropping. I looked around the DON'T TOUCH cap and straight fluid was seeping out all around it.

Looks like the reason they say DON'T TOUCH is because the top of that opening is below the fluid level in the tranny when it is full.

I mowed 2 acres afterward and no overflow. SUCCESS!

Now I can get to my Dad's 65 vintage Ford 3000 diesel that's been in the middle of a restoration for over 4 years now.

Thanks again.

Jim S

 

[glc24]

That's great news Jim!:thumbsup:
I'm guessing being that is a sealed unit is why there are problems with air in the system from a fluid change. Why they (JD) decided to go with a sealed tranny,who knows. IMO,that just causes the type of problem you and many others have to deal with. Glad you're good to go now.


Greg

 

[bullbreaker]

Greg/Jsach Thanks for info ! I did the procedure as stated by JD as Greg posted.Yesterday I cracked my don't touch cap and added a little JD hydro oil to top off. Haven't run my GT yet cause grass is all cut. Will keep an eye on it and post back when I give it a good work out.

:thumbsup:


Boone