Jatco fluid help please

Hi, new here and need help please.

I’ve just had a second hand jatco put in on my 03 td4,
Gearbox changes fine however when the mechanic put it in he drained what was left of my old box which was new fluid anyway (about 4 litres) and put it into second box. I know these boxes take 8.4 litres and he said it was fine with 4 in as the rest is in the torque converter?
is this true or should I be putting a further 4.3 litres in?
To be clear the second hand box was as far as I’m aware empty as in nothing coming out of the drain.

would really appreciate any advice on this as I know jack about gearboxes.

thank you

All depends, as you say, if the TC was drained or not. The correct procedure should be used to set the fluid level, not just adding 4 litres !!!

Best bet is to go through the procedure and check the level as per instructions for changing fluid.
Instructions are on this site, but also in the Rave manual or Haynes manual.
Also, be sure to unscrew the correct level plug as undoing the wrong one can cause internal damage.

This is worth a read...https://www.landyzone.co.uk/land-rover/jatco-fluid-change-–-success.190451/#post-2002760

I must admit that I put about 4 litres in, which seemed to bring the level to within near as makes no odds the correct amount, as the rest remains in the TC.

However I'd never use old fluid in a replacement, especially if it was from a failed transmission, as it could have all sorts of horrible contaminants in it, which could damage the replacement box.

Best bet is to get a gallon on Carlube ATF-U, and do a partial change now, then do another partial change in a couple of thousand miles.

I concur with Nodge, get the old reused ATF out of there ASAP.

You had a failed transmission, so it's got bits of metal rattling around in it meaning the ATF is now acting like a grinding paste, grinding rather than lubricating stuff in the new box. There used to by a bythos about these boxes needing super special dedicated transmission fluid, N402 / N403 but twenty years of fluids improving and nearly all decent quality ATF's have the correct additives in them, and even if they don't they will be better than reused fluid from a failed transmission. Changing the fluid isn't that hard, just heed our advice before you, or your mechanic jump in and undo what looks like the correct plugs.

The following post contains pictures taken from the official land rover workshop manual for these vehicles, and shows you where the correct plugs are. the filler is a rubber mushroom shaped bung on top of the gearbox at the front of the vehicle, the "level plug" is at the bottom of the gearbox near the selector cable. The deal is warm up the vehicle, remove the level plug at the bottom, pour in ATF until it comes out the level plug at the bottom, run through the gears, top up again, and button up the car.

https://www.landyzone.co.uk/land-rover/td4-auto-gearbox-filler.85088/#post-853993

Jayridium said:

There used to by a bythos about these boxes needing super special dedicated transmission fluid, N402 / N403 but twenty years of fluids improving and nearly all decent quality ATF's have the correct additives in them

Click to expand...

Absolutely.
I use Carlube ATF-U, as it's listed as N402 compatible, yet far exceeds the old N402 specification. ATF-U is also synthetic, whereas N402 was a mineral based fluid, also ATF-U is ⅓ of the N402 price, so can be changed much more regularly to keep the transmission is good order.

Not sure if it's mentioned in the other threads, but once you get it up to temperature and top-up, put the level plug back in before stopping the engine !!

Otherwise it will leak back out (and over the floor or your head) as the fluid settles back into the bottom of the gearbox.

pwood999 said:

Not sure if it's mentioned in the other threads, but once you get it up to temperature and top-up, put the level plug back in before stopping the engine !!

Otherwise it will leak back out (and over the floor or your head) as the fluid settles back into the bottom of the gearbox.

Click to expand...

My Jag is the same. The procedure on a Jag is:-
Refill upto the level plug
Start the engine.
Immediately top up to the level plug again.
leave it running until the gearbox is warm.
Top up to the level plug again.
Put the plug back in.
Only once the plug is in can you turn off the engine because if you do turn it off about 1/2 litre immediately pours out.

I think that this is pretty generic to auto boxes.

The other thing is that the Jags are supposed to be "sealed for life", but this implies that you are happy with 100,000 miles as "life". If you want more than 100,000 miles then better start changing the fluid. As previously stated you can never get all of the fluid out. The only solution to that is either one of those flush machines the replaces clean fluid whilst it's running, or what most of us do which is just to keep changing what you can every 50,000 or 60,000 so that at least most of the fluid is not too old.

Lastly, be very, very fussy about transmission fluid specs. Never just use generic ATF on a modern vehicle because it almost certainly isn't good enough.