Oil & Fuel Changed Transmissions oil problem

lzicc · Mar 30, 2013

I am doing 400 hour maintenance on my L3800 HST. I drained all of the SUDT, replaced both filters. I bought a 5 gallon and a 2.5 gallon container of SUDT fluid. I put the 5 gallons in and then started to put another 1.2 gallons in. According to the manual, it takes 6.2 gallons. I cannot see the oil in the check window. The tractor was on level ground. I ended up putting in the 5 gallon and 2.5 gallon and I still do not see the oil in the glass. I don't want to overfill it. In the check window I see the white dot and it does not have a yellow tint to it, so I doubt it is overfull. Any suggestions? THX.

azbinder · Mar 30, 2013

How much did you drain out, and did you check the sight gauge before you drained the oil? The window will be very WHITE when empty or low. If there is any kind of color in the window, then there is oil in it. I would get a clean drain bucket and drain off a couple of gallons and then take a look at the window. Ideally, you want the oil level to be mid way up the window.

Gordon Gould · Mar 30, 2013

The oil level goes by the window very quickly when filling. It is easy to miss. Once the new oil is above the window it is very hard to see.
I did the same thing with my dozer. Kept filling looking at the window every so often. Never saw oil in the window. When I ran out of hydraulic oil to pour in I looked in the tank, it was almost brim full. :laughing: Time for the syphon.
Measure what you take out. Tells you what you need to put in.

gwdixon · Mar 30, 2013

You can always try the trick of parking the tractor on a steep slope. First, glass side up and see what it looks like. Then, park it with the glass side down. See if the color changes. (No, don't turn it completely on its side!!! Some yahoo on here will mention it.:laughing::laughing

That should help diagnose the oil situation and whether or not the sight glass is being interpreted correctly.

Sammy3700 · Mar 30, 2013

I did the same thing on my L3700SU. Luckily I quit at 7 gallons. I thought there was not any oil in the glass however it is so clear I could not see it. I had a new drain pan so I cleaned the side of the tractor good under the site glass and removed the site glass just over half a gallon ran out. Put the site glass back in and waited my wife to slowly pour some as I watced it in the glass. I wound up with 6.5 gallons roughly to the top of the glass. I removed all plugs and left mine open overnight.

Chilly807 · Mar 30, 2013

It doesn't take a lot to go from "no oil in glass" to "all oil in glass", maybe a couple quarts. Drain a couple gallons out and see if the window looks different. If it does, then slowly add a quart at a time until you get a visible level.

Sean

lzicc · Mar 31, 2013

I may try to take the site glass off to see if fluid comes out. The site glass looks white to me, but maybe I'm just not sure. I looked at the white dot when all of the fluid was drained so I could compare what it looked like when there was fluid in there. I don't like the site glass. I wish they would have used both a site glass and a dip stick. This is so hard to judge.

Bluegill2 · Mar 31, 2013

Sight glass on my 3800 is white and full of SUDT. Yes, mine is slightly over filled...

azbinder · Mar 31, 2013

Remember that the sight glass is plastic and when putting it back in do not over tighten it or it will crack at the threads. If you're going to pull the glass and drain the oil down that way, why not just pull a drain plug and dump a couple of gallons and then SLOWLY refill it and watch the gauge. Like I said earlier, when filling, put the level at half way in the gauge so that you will always be able to see the difference.

lzicc · Mar 31, 2013

I had my wife keep a close eye on the site glass and started draining. There was no way I was going to get that site glass out unless I wanted to pull a bunch of stuff out of the way. After draining 2+ gallons, she could see the oil in the site glass. Success. That what really bothering me. I wonder what would happen if I would have left that much SUDT in there.

Chilly807 · Mar 31, 2013

Hmm.. so you only changed about 4.5 gallons? Something's not right here. It takes something like 24 liters of oil, 20 litres being 5 gallons. Did you remove all 4 of the drain plugs? There are also 2 smaller plugs on the lower part of the rear gear housings, at the lowest point. The manual, little gem that it is, only mentions the 2 extra plugs in the section on changing the hydraulic oil, doesn't mention them in the section on changing the filter.

Sean

lzicc · Mar 31, 2013

I only read that there were 2 unless I looked at the wrong diagram. There was one that faced straight down and one that was lower facing sideways. I'm guessing on how much I took out too. I just emptied it in a bucket until my wife saw the oil in the glass.

john_bud · Mar 31, 2013

lzicc said:
I had my wife keep a close eye on the site glass and started draining. There was no way I was going to get that site glass out unless I wanted to pull a bunch of stuff out of the way. After draining 2+ gallons, she could see the oil in the site glass. Success. That what really bothering me. I wonder what would happen if I would have left that much SUDT in there.

Had you left it oil would have puked out the vent. but it might also have blown a seal, not sure but thats possible on other equipment.

Chilly807 · Mar 31, 2013

lzicc said:
I only read that there were 2 unless I looked at the wrong diagram. There was one that faced straight down and one that was lower facing sideways. I'm guessing on how much I took out too. I just emptied it in a bucket until my wife saw the oil in the glass.

Yeah, there's a vertical one on the left side of the driveshaft tube that faces down (or up depending on how you look at it), there's a horizontal one that faces the front of the tractor immediately under where the driveshaft tube comes out of the rear end. And there's two smaller ones on the inside of the lower gear housings on each side. I'm guessing those are the ones you missed (if you did). They put them there because there's no way to get the oil out of that part of the gear case otherwise. Mind you, that's on an L3400, although I think yours is the same.

In the attached picture, the yellow circles show the plugs I'm referring to.

Sean

gwdixon · Mar 31, 2013

Chilly807 said:
Yeah, there's a vertical one on the left side of the driveshaft tube that faces down (or up depending on how you look at it), there's a horizontal one that faces the front of the tractor immediately under where the driveshaft tube comes out of the rear end. And there's two smaller ones on the inside of the lower gear housings on each side. I'm guessing those are the ones you missed (if you did). They put them there because there's no way to get the oil out of that part of the gear case otherwise. Mind you, that's on an L3400, although I think yours is the same.

In the attached picture, the yellow circles show the plugs I'm referring to.

View attachment 310946

Sean

Yep, lots of Kubotas have that arrangement. Not only that, those plugs drain the brake debris and anything that works to the lowest point. Missing those is a big error.

Several models have a screen in the same general area that needs to be removed and cleaned as well.

If it were me, I'd do the whole oil change over again. The filters are probably OK though.

Chilly807 · Apr 1, 2013

Lzicc, how many hours do you have on the tractor at this point? If it was me and it was close to 400 hours, I'd probably do what gwdixon mentioned and change it again to get the remaining oil and debris (if there is any) out.

Mind you, I'd be swearing the whole time, SUDT isn't cheap! If you're less than 400, I'd probably leave it unless my CDO kicked in. In case you're wondering, I call it CDO because "O" does NOT come before "C" and "D"!

I changed mine after I added the rear remotes at about 100 hours on the clock, to flush any debris that was in the hoses and valve bodies. The tractor was almost 2 years old at the time, one year of which was spent sitting on a dealer's lot. The fluid was amber coloured compared but didn't have a lot of debris in it. Mine is gear drive, not HST so I don't know how the fluid condition would compare.

I haven't changed it since, about 330 hours on it now. Just curious, was there much debris on the hydraulic filter magnet? Mine looked like a scrap metal junkyard, lots of machining chips and metal "fur". I thought I was going to break the filter adapter plate getting the filter off, it was he** for tight!

Sean

lzicc · Apr 1, 2013

Crap. I should have read the book better. I had 375 hours on it when I changed it. This is going to bother me now. I may run it like it is for maybe another 100 hours then change it again.