The Classic Machinery Network

Hi All

Guys what is the correct procedure for draining and replacing the transmission oil and filter in a JCB 3CX Grey cab 1988 ?

E.g. does the oil have to be hot?

Any precautions that need to be taken?

Thanks
Bill.

Not sure what the recommendation is but most oils are changed when warmed up. Someone may confirm but, with most torque con transmissions, you will only drain down a % of the oil as there will be quite a lot left in the converter and cooling lines. Some machines have an inspection plate in the bell housing where you can access a t/con drain point.

essexpete wrote:Not sure what the recommendation is but most oils are changed when warmed up. Someone may confirm but, with most torque con transmissions, you will only drain down a % of the oil as there will be quite a lot left in the converter and cooling lines. Some machines have an inspection plate in the bell housing where you can access a t/con drain point.

That makes sense for draining down Pete, but I just checked the manual and it says the oil level should be checked with the machine at rest with cold oil.

I haven't changed the oil on mine , just the filter .
The post from Essex Pete is correct though , ditch the casing oil and then you will need to access the torque convertor through the rubber inspection bung / cover . You can then ditch the fluid that is in the torque convertor . You need to rotate the convertor to get at the bolt or whatever the drain is .
I would be a bit careful filling it up , add about half the book quantity and give it a check . You might find the engine needs ran to get the fluid into the torque convertor .
Personally I'd just change the filter and the oil in the box itself , assuming it looks and smells ok .
What type of ATF are you going to use ?. I had ATF D2 written down as compatible .

Some of these transmissions oil levels are checked whilst the engine is idling or on immediately on stopping. Can someone clarify for the OP?

Thanks for all that useful information

Where is the inspection plate to access the torque converter bung ? I had a peek under the beast yesterday. There is a little plate on the lower left side of the transmission housing which i think is the suction strainer, held by two screws.

Then underneath the transmission housing there is a large Nut which looks like a plug.

So im not sure where the heck to access the Torque Converter to drain it

any guidance on this is appreciated .. thanks

essexpete wrote:Some of these transmissions oil levels are checked whilst the engine is idling or on immediately on stopping. Can someone clarify for the OP?

I think the manual states that it should be checked cold with the engine stopped
Yeah , I was used to checking cars and other vehicles with the engine running and some other variations like being in 1st etc .

Soulman wrote:Thanks for all that useful information

Where is the inspection plate to access the torque converter bung ? I had a peek under the beast yesterday. There is a little plate on the lower left side of the transmission housing which i think is the suction strainer, held by two screws.

Then underneath the transmission housing there is a large Nut which looks like a plug.

So im not sure where the heck to access the Torque Converter to drain it

any guidance on this is appreciated .. thanks

The large rubber bung should be on the bellhousing between the engine and box .
I do not have my machine in front of me , but from what I remember it's about the size of a cigarret packet and is on the bottom face .
Have a good look at the manual , it should have clear steps and pictures , well , I think it does maybe

hi

So i drained the transmission oil via the suction strainer and i manually cranked the engine until i located the torque converter bung and drained that too. I changed the transmission filter and i cleaned the suction strainer.

My transmission oil was a very milky pink so i am going to check the transmission oil cooler to see if it is leaking water into the transmission oil. I think i will bypass the cooler as a test and then see if any water is leaking out from the cooler oil ports, (where the pipes to the transmission were connected to the cooler)

Does this seem like a reasonable test?

Thanks
B.

Hi,
The milky appearance of your fluid could be down to accumulation of moisture from condensation, particularly if it hasn't been changed for a long time.
Condensation will produce water every time a hot transmission cools.
Fred