Just changed the 5hp24 filter and fluid with the help of my part time mechanic. He has a lift. Normally he wouldn't do a sealed for life transmission but I convinced him it was no big deal. On the way up I noticed a droning low rumble at speeds between 30 and 40 MPH. Sounded like driving over rumble strips on the road coming to a toll booth. Rumble rumble smooth, rumble rumble smooth. I was thinking a tire balance issue or something like that. We did the 5 liter and filter for now. I will do the other 5 liters in a few hundred miles. Fluid was very dark brown but not black. Not much on magnets and noting but oil in the pan. Drove home and felt how much smoother it shifted and I didn't think it shifted bad before. The rumble is gone. I feel much better now. Took about under 90 min.

What sort of milage did you have at time of service

119k miles

Good news then for you.
If you intend to hold onto the FF for a long time you have done good by your self and the FF.
I had about 125,000km on mine when I did the same as you, much to the discouragement of transmission mechanics and various workshops.
Interesting that they nearly all said that you dont need to do the filter oil change due to the sealed for life lie.
They will tell you that there is no filter.......this is complete rubbish.
I had lesser milage than you report but I can say my magnets had a reasonable amount of swarf on them, nothing that concerns me having maintained the HP24 in my P38 for the last 15yrs and seeing a slow but steady production of magnetic particles.
Open one of these transmission filters up and you will see that you are well justified in doing a service.

If and when the filter fails your transmission is finished, and you will be up for many thousands of dollars in repairs.

Money well spent, if you can do this your self its pretty easy and not expensive in the scheme of things.

make sure that you recheck the level when really hot, ie it should just overflow (when level) after 10 secs in each gear. and then to park. remove plug, (before check, remove plug, and popping it back in on last ring of thread, ready) but, before removing the plug, ready, check you are not leaking from anywhere round the gasket now that you have had a good test period. if box is slightly low on fluid, some sorts of gurgling drone noises can emminate, esp when turning hard corners.

Pretty sure the manual says 20c for checking the fluid level.
I used a laser temp probe when I did mine. Just check the workshop manual.
Be sure not to overfill thats for sure, as a rough guide its good to measure what comes out when you drain it as well, gives a good idea as to what needs to go back in.

not hot weather, hot engine temp.
after a shortish run, prime the 'gears' recheck level etc. you cant overfill, it pours out, that's the correct level, when it pours out. (gently)
yes, put back in AT LEAST what 'comes out'.

Erm, I was talking about fluid temp.

A) Transmissions fluid level checking.
1) The transmission fluid temperature must be between 30°C and 35°C before checking can begin. Use test equipment to determine the trans temperature.
2) The vehicle must be level with engine running at idle speed and air conditioning turned on.
3) Step on the brakes firmly, apply parking brake fully and shift to D and R, briefly pausing in each position before shifting back to the Park position.
4) With the engine running at idle speed and the selector in Park position, remove the filler plug. Monitor the transmission temperature, if a small stream of oil runs out at 40°C, the fluid level is correct.
5) If no oil runs out when the filler plug is removed, the fluid level is too low and oil needs to be added until it overflows.
6) With engine running, install the oil filler plug and tighten to proper torque.
B) Adding fluid after repairs.
1) With the engine stopped and the transmission in Park position, remove the oil filler plug. Add transmission fluid until a small stream of oil runs out.
2) Insert the filler plug and tighten by hand. Start the engine.
3) With the engine running, remove the oil filler plug and add transmission fluid until a small stream of oil runs out. Insert the filler plug and tighten by hand.
4) Follow the “Transmission fluid level checking” procedure described in section A) above.
C) Notes on fluid level and adding procedure.
1) Use only ZF-LifeguardFluid5 or OEM approved transmission fluid.
2) If the transmission temperature rises above 50°C during the fluid level checking procedure the resulting oil level will be to low. Let the transmission cool down and repeat the fluid level procedure.
3) Have transmission fluid and a suitable oil pump available before starting the fluid level procedure. The transmission fluid temperature will rise quickly during the checking procedure.

OK wasn't quite that precise. Will do with the next drain and fill next week. I made some assumptions from another writeup that it just needed to reach temp and nothing about it exceeding a temp range.

Although it’s good to hear that your fluid refresh has stopped the torque converter lock-up clutch shudder I suspect this will only be temporary. I should start saving up to have your TC removed, re-manufactured and replaced if I were you (approx. £250 + 5 hours labour + filter + fluid). Worn LUC issues most commonly occur soon after 100k miles has been clocked up for the 5HP24 in the Range Rover. It will be interesting to see how long it takes for the cattle-grid noise to return.

Even then you may be able to mask the issue with a fluid friction modifier (Dr. Tranny, etc.) as a further temporary measure but, the fact is, the LUC is worn and ultimately will need replacing.

Phil

Pretty reasonable to suspect that not changing the fluid.......because of the sealed for life BS leads to premature failure of such an illustrious trans as the ZF.
My P38 has a very good shift even after 350,000km and many kilometres of hard bush driving.

You are correct

Change early, and change often

RRPhil wrote:

Although it’s good to hear that your fluid refresh has stopped the torque converter lock-up clutch shudder I suspect this will only be temporary. I should start saving up to have your TC removed, re-manufactured and replaced if I were you (approx. £250 + 5 hours labour + filter + fluid). Worn LUC issues most commonly occur soon after 100k miles has been clocked up for the 5HP24 in the Range Rover. It will be interesting to see how long it takes for the cattle-grid noise to return.

Even then you may be able to mask the issue with a fluid friction modifier (Dr. Tranny, etc.) as a further temporary measure but, the fact is, the LUC is worn and ultimately will need replacing.

Phil

I didn’t get chance to replace mine for several thousand miles after the shuddering began and when I finally got round to it the friction plate still had material left on it. I just replaced the converter, the fluid and filter and all was fine after that. Therefore I would say there’s no immediate panic.

Click image to enlarge

Click image to enlarge

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Bless you. We are packing as I post. My first long trip with the Beast. Theoretically if I don't feel that shudder/rumble return do I not need to worry until it does?