Below is a link to my album related to the ZF 6HP26X, the tranny on the 3.

I am impressed to read of the apparent success of the tranny oil change. Myself, I tend to regard the ZF six speed as very different from say a GM Hydromatic of years previous; hence I found the oil change procedure to be a bit more convoluted as well.

DISCO3.CO.UK Photo Gallery - ZF 6HP26 Automatic Transmission in LR3

 

Well, circling back on this in the spirit of honesty. I'd hate getting guidance from the forum to find out it was half truth. Short story is: my research has lead me to understand that I screwed up the temperature thing, and as such, believe I'm under filled. My symptoms are very noticeable in cold weather which tells me when the fluid isn't expanded due to heat, there isn't enough if it. Great read I found on a jag forum since they use the zf hp26 too

I wandered off the other day to the XJ8 (2004 & newer) section after seeing a thread about ZF 6HP26. Anyhow in short stevetech has sumed up the reasoning behind the temperature monitoring on the refill. Basically puts it in laymans terms for us that don't quite get it (meaning myself).

Again, Thank you Stevetech!


Let me offer some info about setting the correct fluid level if I could.

Everything about this process is based on the premise that hydraulic fluid expands as it's temperature rises. If you know that, everything else is pretty intuitive.

1. When the engine is off (Transmission not circulating fluid) all of the fluid ends up in the pan (with the exception of the 3.xx qts that settle in the torque converter).

2. If you drain everything out of the pan with the engine off (and if the level was correct to start), you will yield approx. 7.5 qts.

3. When you are replacing the 7.5 qts. through the filler port after a pan/filter change with the engine off, you can only get about 4.5 qts. in. If you just capped it up at that point you'd be about 3 qts low.

4. Once the engine is started, the level (from the 4.5 qts put in) drops severely, because the trans takes that much circulating through it.

5. At this point, you can easily add close to 4 qts (engine is running, but the fluid is cold).

6. With all approx. 4 qts in (still cold fluid), you temporarily cap it, then shift through all the gears, slowly, stopping at each interval R N D then back N R P.

7. Now go back to the plug, remove it and start to monitor fluid temperature. I use a direct temp fluid probe on a digital thermometer. I have a special probe shaped like a ...?... that I instert in the filler hole.

8. Now comes the premise part - as the temperature of the fluid rises, it expands. Of the second 4 qts that were added while running cold, some of this fluid will begin to drip out as it expands.

9. Fluid will continue to drip as temp rises, when 40 deg C is reached, that is the ideal temperature, and the level at which the filler hole was engineered into the side of the casing. Simply remove the probe at this point and cap. About 1/2 qt. of fluid will have dripped out.

10. If you exceed 40 C, you're OK, but as you approach 50 C, so much more fluid will have dripped out because of expansion as to leave the trans too short of total fluid needed.

11. If 50 C is reached, then you would have to cap, shut off the engine, let cool down below 35 C, start the engine, refill some fluid (close to a quart) and start over working the temp back up to 40 C.

The temperature does not rise quickly, so there is plenty of time to react to "things". Once I get all the fluid in, go around to shift gears come back, remove the plug and start monitoring temps, I still have about ten to fifteen minutes before 40 C is reached.

Hope this helps.


Pretty good read. Second thing; found a link someone posted here about the car brand names for the zf lifeguard 6 oil since BMW , Audi , Hyundai, Bentley , Maserati and a few others use the same tranny and have their branding of the zf lifeguard 6, but it's the same fluid. Saw "Hyundai" and thought "awesome. This is my ticket to not have to drive 65 min to rover to get fluid or wait a week from atlantic Brit. Called bwm $30 a quart. Called Hyundai. $75!!! Had a good laugh. Apparently the Hyundai guys aren't moving a ton of it.

 

We appreciate the update. As you did, I find that the Jag forum has a lot good stuff on it that also applies to the 3.

The question of the ZF oil price etc continues to be a real puzzle.

Here, at my LR/Jag dealer, a litre of the Jag branded 6 oil costs a bit less than a litre of the LR branded 6 oil, both across the same parts desk.

Nothing much makes sense re pricing of the stuff. As to if it is all the same, well I heard that in addition of the Unobtanium additive that goes into the LR branded oil, Stardust is also added in and hence the price difference.

Myself, I think the price setters have a cookie jar they pull numbers from and that is how the prices are set.