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I know the R380 recommended oil is MTF94, but what are folks running in theirs?

ATF is so cheap and was the original spec for the box that I could/would change it more regularly than i currently do with the MTF. As others may have seen, I have been disappointed with the MTF (and difflock oil) behavior in my overdrive and ATF seems to cope better there, so is MTF really superior to ATF??

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Basically, it is better for synchro life.  It makes it a lot harder to bottom out the synchros when the shift is forced.  However, the synchros can last forever with ATF, as long as you do not force the shifts.

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It’s an odd question I admit. The thing is, my overdrive experiences suggest out of all of these oils atf copes the best. I realise LR used the oil for a reason but I have 25litre drums of atf so it’s handy and quick to use. 

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Your GKN Overdrive works like an automatic gearbox (planetary gears + wet clutches) which ATF is specifically designed for.

MTF is designed specifically for Manual gearboxes, the way they work and the loads they see.

If your gearbox still sucks maybe your gearbox just sucks? I have two trucks with R380s, both use the recommended MTF94 and both work nicely.

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As explained...  The ATF is thinner and will give quicker shift.  The problem is that it is much easier to collapse the synchro oil film and thus damage the synchros.  It all depends on how gentle you are when you play with your shaft.  Some gorillas do not understand the word gentle.

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Ouch! I read this as a conflict between the most suitable oils for the R380 and the OD. MTF for the former but ATF for the latter. I presume that they share the oil? If not then maybe you can move to MTF for the gearbox?

BTW I just ordered new oils from Smith and Allan. They were a good recommendation from someone on here. 

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Yeah, bloomin' manual drivers 😂

Mo

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18 hours ago, Peaklander said:

Ouch! I read this as a conflict between the most suitable oils for the R380 and the OD. MTF for the former but ATF for the latter. I presume that they share the oil?

Roamerdrives share the LT230 oil, GKN have their own little reservoir of ATF that's kept separate.

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Of course FF I’m being a muppet and forgetting about the small matter of the transfer box in between them. Thanks for being so polite in your reply 👍🏻

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MTF - Manual Transmission Fluid.  ATF - Automatic Transmission Fluid.  While ATF can be used in specified manual systems, MTF should not be put in an ATF application, and the GKN overdrive works essentially like an automatic transmission with epicyclic gears and clutch packs rather than like a manual transmission. I think MTF would be too thick for good operation, and could even be damaging, a bit like usin EP90 in an LT77 or R380.  The Roverdrive/Roamerdrive  units have epicyclic gears, but use synchro units with sliding splined hubs just like a manual transmission (the Series version actually uses a SII/SIII 3rd-4th synchro unit), so uses EP90  (or w75 where EP90 is unavailable) and is not comparable.

As for the gear box, I fount MTF94 a fair improvement over ATF in my R380, helping to reduce the common change up into second gear issue and making the transmission quieter as a whole, but it already had well over 100,000 miles on it at that point.  Which is best in a newer box I don't know.  I understand that LT77s are better on ATF regardless of age, but haven't had personal experience of it. 

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I'd agree with snagger regarding r380 performance on mtf. I find it's much more available now than it used to be. Just try each and see what you think. 

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MTF is interesting - it's a "modified friction" oil which means that under some conditions its lubricating-properties are designed to *decrease*.

Think about it - the working of synchros depends on there being friction between the components! A spectacularly-slippery oil disrupts this necessary friction and means the synchros must take longer to bring the gears up to matching-speed before they engage. (This is also why stuff like Molyslip can mess-up synchro operation - it ruins the controlled friction in the synchros).

I don't find problems getting hold of MTF94 for my R380, and it's cheaper (buying in bulk) than any of the 'trick' oils sold to motorsport-types-with-more-money-than-sense.

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On 5/15/2018 at 3:48 PM, reb78 said:

I know the R380 recommended oil is MTF94, but what are folks running in theirs?

ATF is so cheap and was the original spec for the box that I could/would change it more regularly than i currently do with the MTF. As others may have seen, I have been disappointed with the MTF (and difflock oil) behavior in my overdrive and ATF seems to cope better there, so is MTF really superior to ATF??

Shortly after I bought my Disco 300 TDi, I had a discussion with a LR mechanic about maintenance issues. He then mentioned that I should only use MTF, as it is better than ATF, which was the previous oil spec for the R380. He proceeded to take out two plastic bags from a drawer and unpacked the contents. Both lots were R380 gearbox bits, both did about the same mileage. The ones from the ATF box had, visibly, more wear on them than the ones from the MTF box. I have been using MTF ever since

I bought my Disco with 120 000km on the speedo, and now, at 392 000km, it shifts as smoothly as ever

The problem that I have is that MTF is not that easy to obtain in South Africa as it is in Europe. 

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On 19/05/2018 at 11:17 PM, Tanuki said:

MTF is interesting - it's a "modified friction" oil which means that under some conditions its lubricating-properties are designed to *decrease*.

Think about it - the working of synchros depends on there being friction between the components! A spectacularly-slippery oil disrupts this necessary friction and means the synchros must take longer to bring the gears up to matching-speed before they engage. (This is also why stuff like Molyslip can mess-up synchro operation - it ruins the controlled friction in the synchros).

I don't find problems getting hold of MTF94 for my R380, and it's cheaper (buying in bulk) than any of the 'trick' oils sold to motorsport-types-with-more-money-than-sense.

ATF is friction modified, but the friction modifiers used aren't ideal for manual gearbox synchros, they are formulated for wet clutches.

Basically the FM's used in an MTF have a coefficient of friction that increases with decreasing rotational speed, oils like engine oil used in the LT95 actually work the other way around resulting in a stick/slip style situation so you sometimes 'beat' the synchros.

Mostly MTF's will also give better gear/bearing protection too.

 

In high ambient/high load conditions (eg. Southern Europe, Africa, Australia) ATF's and lighter MTF's can become too thin resulting in bearing rattle and eroded shifting performance.

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On 5/19/2018 at 10:17 AM, Tanuki said:

MTF is interesting - it's a "modified friction" oil which means that under some conditions its lubricating-properties are designed to *decrease*.

Think about it - the working of synchros depends on there being friction between the components! A spectacularly-slippery oil disrupts this necessary friction and means the synchros must take longer to bring the gears up to matching-speed before they engage. (This is also why stuff like Molyslip can mess-up synchro operation - it ruins the controlled friction in the synchros).

I don't find problems getting hold of MTF94 for my R380, and it's cheaper (buying in bulk) than any of the 'trick' oils sold to motorsport-types-with-more-money-than-sense.

Interesting and would also explain why, around the time of the ATF/MTF changeover which was about late 90s, some of our customers at the time changed to MTF, reckoned that the gearshift was not as good, and changed it back again.

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Adding my own experiences in for good measure ;)
200TDi Defender with a stumpy R380. Always used ATF over 18 years of ownership, and changed it frequently.
I drove down the west coast of Africa, did a major service in Cape Town with a independent Landy workshop. They insisted MTF was the way to go.
Gearbox was really noisy, harder to use, changed it back to ATF within 500 km's and all was fine again.
I'm carrying a fair load and driving in hot climates.

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I just drained my old slightly burnt ATFII and swapped to ATFIII.  Had hoped the change to fresh fluid would fix the slight catch I was getting on the change to 2nd .

Have done 1000 miles on it, no improvement over the old fluid, if anything the 2nd gear change is marginally worse. 

I'll be trying mtf next time.

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4 hours ago, roamingyak said:

Adding my own experiences in for good measure ;)
200TDi Defender with a stumpy R380. Always used ATF over 18 years of ownership, and changed it frequently.
I drove down the west coast of Africa, did a major service in Cape Town with a independent Landy workshop. They insisted MTF was the way to go.
Gearbox was really noisy, harder to use, changed it back to ATF within 500 km's and all was fine again.
I'm carrying a fair load and driving in hot climates.

I should have added I have a gearbox oil cooler fitted next to the radiator.

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22 hours ago, roamingyak said:

Adding my own experiences in for good measure ;)
200TDi Defender with a stumpy R380. Always used ATF over 18 years of ownership, and changed it frequently.
I drove down the west coast of Africa, did a major service in Cape Town with a independent Landy workshop. They insisted MTF was the way to go.
Gearbox was really noisy, harder to use, changed it back to ATF within 500 km's and all was fine again.
I'm carrying a fair load and driving in hot climates.

It can take a good 800km for the new friction modifiers to displace the old ones when swapping fluids, in the meantime you may get crashing of the synchro's etc.

Having said that R380's can be idiosyncratic but most perform better with a dedicated MTF

  • Thanks 1

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On 5/19/2018 at 10:16 PM, Sabre said:

Shortly after I bought my Disco 300 TDi, I had a discussion with a LR mechanic about maintenance issues. He then mentioned that I should only use MTF, as it is better than ATF, which was the previous oil spec for the R380. He proceeded to take out two plastic bags from a drawer and unpacked the contents. Both lots were R380 gearbox bits, both did about the same mileage. The ones from the ATF box had, visibly, more wear on them than the ones from the MTF box. I have been using MTF ever since

I bought my Disco with 120 000km on the speedo, and now, at 392 000km, it shifts as smoothly as ever

The problem that I have is that MTF is not that easy to obtain in South Africa as it is in Europe. 

If you struggle to find it, try Honda dealers

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I’ve got a stumpy r380 fitted and from new I’ve always used MTF94, but what I did find was I put Granville MTF in to start with and the gear changes were rough , changed to genuine Land Rover MTF and the gear changes are a lot smoother and she’s a lot nicer to drive .

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