THE INTERNATIONAL JAGUAR 'S'-TYPE REGISTER FORUM

There is some seal swell additive in Type F & G fluids but only to control designed swell. Once a seal is worn/damaged it should really be replaced. That Lucas product is just a band aid. The leaks will return sooner or later.

I found Jaguar TSB FF23 from April 1969, which recommends M2C 33F (Type F) ATF for all automatic gearboxes, including the DG models. So, my witterings about Type A above can safely be ignored.

Type F & Type G fluids are fungible & miscible. Type G offered improved shear stability and oxidation resistance. Also better performance at low-temperature over type F. Not a huge change.

Glyn, please stop using those big words.

awiedie wrote: ↑Thu Feb 07, 2019 1:27 pm Glyn, please stop using those big words.

LOL!

Whilst we are on the topic of automatic transmission fluid, I asked Graham Whitehouse why my DG gearbox leaks (even) more when I don’t use the car much (eg. over winter).

His reply was...

"When you leave the car standing the torque converter drains back into the gearbox and raises the oil level higher than normal and it reaches parts that aren’t sealed ( eg speedo cable etc )."

So now you know. Thought that might be of interest to someone.

Very interesting, Orlando. I received the same explanation from a local transmission shop regarding my leaking box. He suggested that I put the car up on jack stands, wipe down the box and bell housing to clean off all leaking oil, and then periodically check beneath the car to see where the leaks are coming from, even taking a photo. When the weather gets better, I may take the car in for a look around at my transmission. Drain-back from the converter seems plausible.

Hi Alan. Yes, I have been down that route, too. It comes from every available joint/seam/thread/bolt/nut! Yes, it really does come down the threads, particularly the brake band adjusters. Of course, on the DG box, many of the ancillaries are bolted on to the outside - rear extension, solenoid, anti-creep switch, etc - and every one is a leak opportunity. In later models, these devices were either done away with or mounted internally.

Graham Whitehouse also tells a story about a gentleman who purchased an Alvis and took it back to the factory, complaining about leaking ATF. The Alvis chaps made him up a nice drip tray! They knew they couldn't stop it leaking.

Graham says he can stop them leaking by sealing every joint/seam/thread/bolt/nut. But he will only do that as part of a full rebuild.

I've come to think of my leaks as being 'period correct'.

I agree with "Period correct" as I was once told that Jaguar built in the oil leaks as an anti rust mechanism for the underside of the car.
No Waxoyl (1972) or stone chip paint in the 60s.lol.