Type 8 gearbox oil change

Hi all
My gearbox oil is I think a mixture of various types added over the years and although it doesn’t smell or look burnt it isn’t the nice red colour it should be, more towards brown. I don’t know if it has ever been changed so I have managed to get 20 litres of type F transmission fluid and would like to change the fluid and filter in the type 8 box on my early series 1. I can’t find any instructions on how it should be done. The Jaguar manual E155 seems to have no instructions at all and a search of this site turns up a few posts which say that a partial change done 3 times or so will complete the job. First thing is that I can’t find a drain plug on the oil pan, The filler tube goes into the side of the oil pan so I suppose removing that will drain part of the fluid away. I have a new filter and gasket for the pan and will be changing the exhaust system next week which will make access to the pan bolts easier.
What I need is description of how to do the job written by someone who has done it. I’ve read of and can locate a bolt in the torque converter which serves I think as a drain for that but how do I refill the torque converter given that most of it is higher than the oil pan? should the engine be running for example whilst the new fluid is being added? Do I also need to drain and refill the oil cooler and if so how.
I have no experience of auto boxes so should i leave the job to a professional or can it be done by me, a reasonably competent mechanic with a good range of tools and a 4 post ramp at my disposal. I have a worry that I’d drain it all out and couldn’t refill it, irrational probably but there you are. Can someone point me to a description of how it should be done

Thanks for any guidance

Ian

Its easy, the big nut that holds the dipstick will drain most of the fluid.

apart from that, the pan gasket change will get rid of most of the rest

its as simple as that. The pan gasket is the same as a Ford FMX.
The filter is a wire screen, which only needs washing out.

on some cars the exhaust is in the way, in others not

You’re right, it shouldn’t be brown.
I’ve done my BW Model 12 in my '74 XJ12. The trans oil cooler will drain into the pan. After you get most of it out through the fill tube port, take all the pan bolts out, being careful not to spill the rest in your face. It will keep dripping forever.
Drain the torque convertor through that bolt you located.
Clean the filter.
If there is a magnet in there, clean it.
Now look at your pan bolt holes, they are probably dimpled upwards. Bump them down 1/32" below flat, so the bolts will compress the pan evenly all around the gasket as you tighten them. Use a new gasket but no sealant.
If you’re weird like me you can take this opportunity to drill a drain hole in it and weld on a threaded fitting for a drain plug.
Fill the specified amount if you know it, otherwise fill to the line and run the engine, filling more while its running as it gradually goes into the torque convertor and cooler.
Check for leaks.

I advise against this. The big nut on the filler tube drains just about as low as you can go.

I did what you did, and discovered this afterwards!

The drain spigot has to be very low down, such that it is vulnerable to knocks, which happened to mine, and it leaked (if you do, dont have an external nipple, but a plug, preferable internally recessed)

I refer to a BW8, so there may be some difference, but I do not think so

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You have to drop the pan to change the filter, Ian…

Just changing the fluid can be done in various ways as other have described - and the fluid should be hot. The manual states that fluid cannot be completely drained in-car - probably valid for all methods. The residue should cause no problems…

So when refilling, engine not(!) running, the manual suggests filling to 3/4 of ‘dry’ specs, 19,8 US pints - ie refill some 15 pints. Then adjust level as required with the fluid hot - engine should idle while measuring levels…

You need to replace the gasket, of course - and do check for pan bolt holes distortions as Rob says. A common cause of post change pan leaks - caused by overtorqueing the bolts…

It’s a straight forward DIY job…:slight_smile:

Frank
xj6 85 Sov Europe (UK/NZ)
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Maybe yours is lower than mine. It didn’t seem to be a problem with mine. Nevertheless, something to take into consideration.

Thanks gents, put my mind at rest a little. I’m away this weekend so will hit it next week when the exhaust arrives. By the way Frank, I see you are a Kiwi, I will be spending November and December based in Nelson, are you anywhere near there?

Ian

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Negative, Ian - I’m in Tauranga…

Frank
xj6 85 Sov Europe (UK/NZ)
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Did the gearbox oil change this week whilst fitting a new exhaust. I found that the pan bolts that are difficult to get at under the exhaust were all slightly loose hence I think the slight leak from the pan, The bolt holes were not crushed or proud so left alone. The fluid that came out was not great, quite dirty and brownish rather then the usual red,The inside of the box was however quite clean. I was amazed how long it kept on dripping out fluid, more than 24 hours and still it dripped. No metal or anything suspicious in the filter so I washed and reused the original and having been able to drain out around 7 litres of ATF I replaced it with new Type A fluid and the gearbox is now a different animal, much smoother changes and no failing to prime or engage. I guess the old ATF had been in there quite a while and was probably a mixture of different grades added over the years. A job well worth doing, particularly if the pan no longer leaks, I had bought a 20 litre drum of the ATF so in a year or so I’ll drain it again and refill with more fresh fluid to get out the remnants of the original ATF.

Thanks for the advice.

Ian