I'm in the process of replacing all of the fluids and filters in my 2004 Supercharged 4.2lL XJR to establishing a baseline. Does anyone have any advice concerning the feasibility of and drain and fill vs a flush and fill. Also is there a procedure for flushing the tranny?

 

Hi joeleerj,

Use the Advanced Search function under the Tools tab near the top of this page to search "Transmission Fluid" in the X350 forum and S-Type forum. You will find more than you ever thought you needed to know about the ZF 6HP26 transmission in your car. I've got to get to bed so I can't list the bullet points right now, but you'll definitely want to do your homework.

Cheers,

Don

 

As Don B stated you need to research this forum. Lots of info regarding bolts, sleeve, pan/filter and of course fluid.

I went with ZF recommended fluid as it really is not that much more expensive than the alternative if you find the right place to get it.

The procedure is very important.

You will find that most people just do a drain and fill.

I did a flush and fill and replaced at least 95% plus of the old fluid. You need to know how to detach the inlet from the transmission cooler into the transmission.

I did exactly what you are doing when I purchased my 2005 XJR and I did the belts as well.
You need two people to do the flush and fill.

It is really not much more work than the drain and fill.

 

Btw it helps to know what the inside gears look like when doing the SC oil change.

You need a fine tube to poke down below the gears to suck out the old oil.

Note where the oil fill plug is on the snout view in relation to the gears.

The pics are "upside down".

 

Thanks for the heads up, I'm still trying to learn how to navigate all the features of this site

 

Thanks, I forgot about the belts. I'll look up how to do the complete flusn

 

I have only seen one other person on here that has done a complete flush as a DIY. A dealer would use a special machine.

I had already performed a completer flush on a truck that I have so I knew I could do it on my 2005 XJR.



The procedure involves undoing the transmission cooler feed outlet pipe back into the transmission during the refill procedure.

Thats the "best" way to do it. However it is difficult to undo just the one pipe as the inlet and outlet are clamped onto the transmission together.

So I detached both.

You then need to be able to deflect fluid as it is ejected from the transmission when the engine is running into a large container.

You can only afford to do it with the engine running for 1-2 seconds because of the volume of fluid ejected. You do not want to be more than about a quart low.

Thats why you need one person who starts and stops the engine and one person who pumps clean fluid in thru the fill plug hole.

I estimate I did about a quart at a time once I HAD ALREADY performed a simple drain and fill.

When clean fluid is ejected you have completely flushed the old fluid out.

You then drain the cooler of old fluid and reconnect the cooler pipes to the transmission.

Then you have to complete the fill at the correct temperature and run thru the gears as you would normally with a simple drain and fill.

One word of warning though do NOT stop the wheels from spinning suddenly when going thru the gears.

If you are up on stands the momentum of the turning wheels could cause the car to topple off the stands if they stop suddenly as that energy is transferred to the whole car.

 

Thanks jackra_1, that's the exact info I was looking for. I'll attempt as so as my trans fluid arrives. btw, you guys on this forum are great. I'm learning so much.
Thanks A+++++

 

There are a couple of U tube videos on the drain and fill that are good.

The big hassle for me was getting the car jacked up and level.

I also checked the fluid level after driving the car and found that I had to put in a few more ozs, maybe 2 ozs, of oil.

I used an infra red "gun" to measure temperature.

Take your time and dont rush.

 

Thanks jackra_1
feel comfortable with the drain and fill. It's the flush and fill I need to see. What type of infrared "gun" did you use and where did you point it to get the fluid temp?

 

I got it on Ebay I forget the manufacturer, not expensive. I aim it in the center of the pan and figure it maybe a couple of degrees lower than the actual temp of fluid inside.

Very useful device for checking on coolant flow thru hoses and radiators.

Most people do the drain and fill and do not seem to have any issues with the transmission. Many do another drain and fill a few thousand miles after the first thus diluting the old fluid a bit more.

However its a great feeling to know you have ALL the old fluid out or close to it.

I was comfortable doing it because I had experience doing it with my Dakota truck where the fluid was burnt so I wanted o get all of that out of the system.

When I did it on the Jag I was completely surprised with the force of the oil ejecting out of the transmission . I had to use a large plastic lid to deflect the flow down into a large pan.

 

Thanks for the info about the temp gun. I want to do the flush and fill, I would just like to see it done (you-tube) to make sure I doing it right. If not I believe I can figure it out. Thanks again.

 

If you are doing the transmission fluid, filter and pan, you should also check the Electrical connector socket that is known to leak on early units. These have orange O rings. I have a spare available for the cost of postage if you wish.

The change kit from "The CTSC" includes some spare pan bolts and the associated connector, along with 6L of oil.

Changing the connector involves turning the locking plug about 1/4 turn left and releasing the connector lock accessible after pulling the pan, then pulling the housing out. The new one presses in, using some leverage.

The other thought is changing the valve body seals to the transmission itself. These can be changed after removing the valve body, just 9 T40 TORX. The BMW crowd swear that these can leak and/or crack and loose pressure. I just changed mine after doing 170k Miles. The mechatronc adapter looked ok, but the other seals were pretty hard.
The seals are 4 short rubber seals, just pressed in with finger, and one adapter, just sitting there.
Mechatronic adapter: 0501 219 952 01 $17
Sleeve kit: slk_26_28_32 $22

I am pretty happy with my gear changes and smoothness of shifts since then, and the small squawk on the 2-3 change has gone.

 

Thank for the info. If you have the O rings, I would be glad to take them off your hands, just send me the mailing info. Do you teardown the valve body for inspection, cleaning etc..

 

If I had known about those rubber seals beforehand I would have changed them.

Some people have had trouble with the "connector" when trying to put it back in and the suggestion is that you measure how far in/out the original one is and aim for the same measurement when putting the new one in.

I had no trouble at all.