Thank's for help swoop223!
I found a serial number in engines cylinderblock and it is:
4D95L-19117. So it is a Yanmar engine?
Does anyone have details on this type of engine?

Side of the transmission case is casted number 3EB-15-1111.
Obviously this is case's part number?
Does somebody know where is the real serialnumber, is it on left or right side?

Btw, what do You mean that oil type is TO? Is it Transmission Oil, in other words ATF ?

I'm still looking for pictures or repair manual of this type of transmission...

- Gary -

it is a torqflow transmission type L
that number is not the serial number, it is a part number for the body on the control valve.
As for the type of oil it takes i believe it uses a TO type oil.

As for the engine?
will need some numbers off the block to know for sure
there were a couple different engines they used in this truck
c240 isuzu and 4d95s

In tranny cover is number: 3EB-15-18511
I think this is the type of it?
In AIT's homepage I found same type transmission, they still not have exactly this number of transmission.
www aittransmission com

Btw: Does anyone know anything about the diesel-engine?
In rocker cover stands Komatsu but is engine Komatsu's manufactured or is it for example Yanmar?

Ok.
I try to find any id's of the transmission.
Maybe I take a few photos of it.

- Gary -

i would do the pressure test beforehand.....
then....
remove the control valve and check the clutch pack

your choice though....
if the clutchs are worn out you'll know it
just go by that which L1ftmech suggested on how to check

as for the fluid there are a couple types that are dextron and/or clear transmission fluid....
i was looking in the manual for this model and there are several breaks in the model and it displays several transmission sections for manual shift clutch type, and 2 other automatic torqueflow type ones.
can you find any tags on the transmission housing and see if you can pull any info off it. That might help determining which one it has and then we can determine what fluid goes in it for sure instead of guessing at it. ;o)

Thanks L1ftmech!

Next thing that I'm going to do is remove the control valve in transmission case and take a look at inside.
Then I change transmission oil on ATF (Dexron III) and see what happens.
If it does't work then I must do the pressuretest.

We once had some FG25ST-4s and FG25ST-8s in our company fleet (they have all since been sold).
The service manuals we had for those trucks specified Dexron II.
With the advent of Dexron III in the early 1990s we began using Dexron III in the fleet. Dexron III is "backward compatible" with Dexron II.
While the clutch discs cannot be replaced without removing the transmission from the chassis, the clutch discs can be somewhat inspected by removing the control valve from the transmission case.
Once the control valve is removed you will be able to see the edges of the discs through the spaces of the clutch drum.
The metal clutch plates are mated to the clutch drum with "drive tangs" on their outside (circumference) and these discs are all steel.
The friction discs are mated to the clutch pack center hub with "splines" and have friction fiber media on their faces.
You can look at the friction discs edges and tell whether there is any friction media remaining on their faces by noting whether there is a very slight spacing between each friction disc and its adjacent clutch plate disc. If the friction disc METAL SURFACE is completely against the clutch plate disc.........there is no friction material remaining. You may also pry the discs apart from each other with a flat blade screwdriver to get a better view.
Another thing you must check for on the friction discs is to note how these discs are "resting" in relation to all the other friction discs in the pack. If any of these discs seem to be lower on their edges than other discs......the internal splines are likely "shelled off" or beginning to.
You also can place the edge of a flat blade screwdriver against the circumference edge of each friction disc and try to rotate the disc. If you are able to turn the disc, it has shelled off all of its internal splines. You should not be able to turn a friction disc in this manner and when a single friction disc moves, it should move ALL the other friction discs in unison.

It's not red ATF. It looks like hydraulic oil.
Is it possible that someone have filled wrong oil on transmission and that causes problems?
Dipstick has no information on oil quality or quantity.

On the other discussion on this forum are id's for Komatsu FD20/30 and there is listed that transmission oil quality is ATF.
(discussion: "Technical Arena" #5770)

I have to be sure on that oil quality. Do You know where I can get right answer?

red color fluid?
most likely is dextron and dexIII will work

if it is clear then check the dipstick and see if it lists the type of oil on it(most do), generally it will be a 10wt transmission oil.

Thank's Jplayer!!

I tested my forklift today after it has been stand alone for 4 days. It worked again couple of minutes. Both directions are working. Then tranny starts to slip and it moves nowhere, just engine revs.

I'm gonna first change transmission oil and see what happens. What is correct oil quality? Must I use Dexron II ATF-oil or hydraulic-oil?
If it does't work I'm gonna test those pressures.

Does anyone have a picture of this type transmission? Is it possible to change worn discs without taking tranny out of lifter?

- Gary -

hi gary,
well most certainly dark fluid is not a good sign.
but for starters i'd change out the fluid and filter and clean the sump screen if there is one at the base of the trans housing.

many things can cause no movement
- low oil level (which you already discounted this one)
- oil pump drive
- torque converter system
- bad clutch packs
- inching valve system
- clogged oil flow
- faulty control valve

i guess i could keep naming things but these are for starters.
i'd also get a guage and check pressures at the control valve, torque converter pressure and clutch pack pressure. converter pressure should run around 43-100psi @ 1500rpm, and clutch pressure should be 149-199psi. There should be 2 ports on top of the tranny, one ON the control valve for clutch pressure and one just behind the control valve on the case just to the left side rear of the control valve for converter pressure.