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hi folks it a way off yet but mot is due on my l320 sport
so would be a service and MOT local garage will do this they do it every year and know thier way around a range rover (owner has a 1965 series llA )
anyway do I go down the route of standard gearbox oil and filter change or should I send it send off for a transmission flush?
I'm more for oil and filter change just wondering has anyone gone down the flush route ?

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P38 service schedule says gearbox oil should be changed every 24,000 but I doubt anyone does that (with a filter change ONLY on the first service at 24,000). However, you've got a totally different gearbox on an L320 so no idea. There's one box fitted to certain later models (a GM box I think) that is notoriously unreliable where they always recommend a flush.

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don't know it the engine makes any difference I've got the 4.2 jaguar AJ-V8 lump
with adaptive six-speed ZF 6HP transmission (ZF6HP26) ZF automatic transmission,
might have to do a bit more research 🤔
thanks Richard

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A ZF should be OK, i think it is a GM box fitted to some diesel models that is weak.

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I know the diesel ones or prone for turbo failure think your right other gear box to
would you say I'd be best going with gut feeling and just stick to normal service and drop the pan and new filter job

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Gilbertd wrote:

P38 service schedule says gearbox oil should be changed every 24,000 but I doubt anyone does that (with a filter change ONLY on the first service at 24,000). However, you've got a totally different gearbox on an L320 so no idea. There's one box fitted to certain later models (a GM box I think) that is notoriously unreliable where they always recommend a flush.

24,000 you say? erm. Oops!

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I am convinced, and colleagues that are auto box service/repairmen, always recommend a change at no more than 40K km for any type of auto box, regardless of what the manufacturer says. Fresh fluid can't hurt, especially considering the thermal stresses is subjected to. No-one recommends flush, but partial changes, or, if you are keen and diligent, you can get to a full change by opening the circuit in one of the cooler outlets and therefore replacing more fluid than with the standard drain/refill (including the filter/strainer).

The Audis that we service, that mount the 6-speed ZF 6HP26A ("A" is the Audi derivative, with the transfer/front diff in the same case), fall into that category as well. For those we drain and refill only as above, no flushing.
I would never flush on an unknown box, danger of freeing impurities that can complicate things is high.
If you do open the box and proceed to a full cleanup then is ok.

Now I got a question for the fellas ... what ATF you use in yours? I am not interested in brands, but type. I've replaced mine (partial drain/fill + filter/strainer, this was before I've perfected the method above) when I bought the car (239K km) and then I've done another one at 254K km. I plan the next in another 30K km, if the box holds as much ....
I've used Mobil 320 Dextron III type on both occasions, but now I have learned there are many "varieties" of Dextron III, ranging from C, D, H, J, and so on. Anyone has a clue that is the correct type for our old gearboxes?

I got a friend that made a total flush and went with Dextron VI (the full-synth) and he says his box changes much better, but I am afraid to try ....

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I should have specified 24,000 miles, so that will be roughly 40,000 kms. This https://www.opieoils.co.uk/p-745-castrol-transmax-atf-dx-iii-multivehicle-automatic-transmission-fluid.aspx is what I put in mine.

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leolito wrote:

Now I got a question for the fellas ... what ATF you use in yours? I am not interested in brands, but type. I've replaced mine (partial drain/fill + filter/strainer, this was before I've perfected the method above) when I bought the car (239K km) and then I've done another one at 254K km. I plan the next in another 30K km, if the box holds as much ....
I've used Mobil 320 Dextron III type on both occasions, but now I have learned there are many "varieties" of Dextron III, ranging from C, D, H, J, and so on. Anyone has a clue that is the correct type for our old gearboxes?

I'm going to use a 75W 80 fully synthetic gear box oil in mine not to bothered on the brand as long as it the right oil

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Not in an auto box it isn't, it'll want Dexron 111 but check to be sure. 75W-80 is for a manual box or axles.

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Don't put 75w80 or DEX 3 in the 6hp26 for godsake.

ZF Lifegard 6 is the correct and only fluid that can be used, a genuine kit is £250 which includes instructions on how to do it as there is a procedure to follow.

Don't follow the procedure or use the wrong oil and you'll fuck the box.

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dex 111 is about 30 grade oil not 75 80 multi grade i have heard people have trouble with dex 4 so don't use that either in a zf 22 / 24 box , as for the 6 speed i have had no experience on them so my advice is to read the service manual .
PS be very careful with transmission oils,as oils ain't oils, sole. you will do damage , and to remove the oil is very difficult when they are mixed up

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Yep on all the above.

However ......

We build what we claim is the world's best 4x4, but make it impossible to field service. Ah well, best on the forecourt perhaps.

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thanks folks I looked at the wrong oil good job I said on here

https://www.jgs4x4.co.uk/range-rover-sport-l320-automatic-gearbox-easy-change-filter-kit-comma-mvatf/?gclid=Cj0KCQjw3eeXBhD7ARIsAHjssr_4eZKjfNaOCWCaIdJlqfLnOgh4jOY0CSaqmKFUV04V8fgF5j6QR5oaAudVEALw_wcB
it going to garage so will speak to them what they would advise was thinking of getting this kit for them

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Thanks Richard, I see you use 'H' type which is the same I thought to use (was valid until 2004, so surely compatible with our "old" boxes).
I think also the manual R380 and transfer use ATF, so I would leave 75W-80 or 75-90W for the diffs.

Even for the diffs, I am wondering if 75W-140 would be a better choice ...

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I find it's better to stick with what was current at the time something was built. I did a diff oil change some years ago and decided to put Millers fully synthetic 75W-90 in and they both immediately started whining. Drained it out and put old school mineral 75W-90 in and the whining went away.

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I think mine got ep90 in diffs

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75w-90 for gear box oil in my gearbox

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Huh? But you've already found the right stuff. Or do you mean 75W-90 for the diffs?

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y
Gilbertd wrote:

Huh? But you've already found the right stuff. Or do you mean 75W-90 for the diffs?

yes sorry was ment to say diffs the mechanic has got me to order the kit I posted (comment 14 ) diff oil will be ordered today engine oil was done last month so that will be good till next year or if the milage comes around quicker