Changing the transmission fluid on any car or truck is a vital part of preventative maintence.

Read your owners manual but it is generally recommended that you change the transmission fluid every 30,000 miles and the filter every 60,000 miles.

By doing this cheap preventative maintence you can help insure a long and healthy life for your transmission.

Land Rovers use Dexron III, try and buy a name brand like (Valvoline High Mileage ATF) 6 quarts on hand for this, 8 quarts for when you change the filter too.

You will need a 8mm allen wrench for the fill/check plug and a 5mm allen wrench for the drain plug.

The drain plug is on the bottom of the transmission oil sump and the fill/check plug is on the front of the transmission sump.

Remove the fill/check plug and then place your drain pan under the transmission sump and remove the drain plug.

Once all of the fluid has drained out clean the area around the drain plug and make sure that you clean the drain plug threads and that the washer is still in place.

Then using a hand pump such as this that you can buy at any store for around $10 US refill the transmission.

Pump the new transmission fluid into the fill/check hole until it starts to come out of the hole, replace the plug.

Start the truck and leave it running (make sure not to come into contact with the extremely hot catalytic converters). Then shift though all of the transmission gears and hold each one for 2-3 seconds, starting in park and continue until you reach 1st, then go back to park.

Reinstall​ the fill/check plug and make sure that the transmission is full, fluid should come out at a nice steady rate, if so you are full.

Pour your dirty transmission fluid into a container and take it to be recycled, any quick lube oil change place will take it as well as autoparts stores.

Budget one hour for this job.

 

Hi Spike,
I saw a Mobil 1 Synthetic ATF labeled Mercon V can I use this for the Disco 1?
I also saw Valvoline DEX/MERC ATF? What is Mercon anyway?
Thanks man.

 

That is the up-grade name for Dextron, it can be used in your truck but you must have it installed thru a flushing type machine to first get rid of all the old, none systhetic fluid, then put in the synthetic, other wise it is a waste of money to only put 5 quarts of new synthetic on top of 7 quarts of old fluid.

 

I see, so there is a machine that cmpletely flushes the ATF? Can I just drain the entire ATF like what Spike did above?

 

Our tranny holds about 12 quarts but when being drained, only 5 to 5.5 quarts will drain out, the rest stays in the torque converter and upper body area.
Yes, some shops can flush them, don't have the chemical flush performed if you are close to 100,000 it will be hard on the tranny.

 

No you cannot drain out all the ATF, there are nooks and crannys and the tourqe convertor and the filter that will still hold fluid.
Draining it such as I did only removes maybe half of the old fluid, as long as this is done regulary there is no problem.
If you want you can change the fluid, drive it for a week, change it again and then you will replace more of it that way.
Most quick lubes have the machine that with exchange all the fluid as well as mechaninc's.
The quick lube will charge you around $100, a mechanic will charge you more.
Honestly though, as long as you change the fluid every 30,000 miles and the filter every 60,000 miles the transmision will last as long as the rest of the truck.

 

Where is the filter and is it difficult to change? If not, could I get one at a local auto parts store and what kind is recommended?

I have a D1, btw.

 

On a DI the transmission filter is very hard to change, it is located inside the transmission oil pan just like on the DII BUT on a DI the y-pipe and a cross member both need to be removed.
Depending on your mechaincal skilss and tools it is best if done by a shop.
If you want to change the fluid and wait and do the filter later then it si a 30 min job.
Remove the drain plug, refill through the dip stick tube with new trans fluid.

 

I've got no skills, but a buddy has a half **** shop. It's there right now getting all the bushings changed. Was gonna get the tranny fluid changed too. Could I get a filter at Autozone?

 

Yes you should beable to get a filter kit at AutoZone, the kit will include the filter and gasket.