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I would be very suprised if mtf94 is actually 10-40 i wuld say it is alot thinner than that!! i have been playing with motul 300v which is a 3 ester fully synthetic oil 15/50 egine oil,so far it has been alot better i.e shift and noise plus temps are down a few '0c!!!!! indicating less friction.

chris

Edited by northernchris
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I would be very suprised if mtf94 is actually 10-40 i wuld say it is alot thinner than that!! i have been playing with motul 300v which is a 3 ester fully synthetic oil 15/50 egine oil,so far it has been alot better i.e shift and noise plus temps are down a few '0c!!!!! indicating less friction.

chris

I used MTF94 (gen part) in my recently recon'd LT77.... I have to say I thought it was c**p - notchy / difficult shift, esp when cold - made the truck a pig to drive.

I went over to a semi-synthetic ATF - nothing fancy, Carlube I think (IIRC) and things have improved dramatically. It now drives like it should and changes are silky.... ;)

Matt

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I would be very suprised if mtf94 is actually 10-40 i wuld say it is alot thinner than that!! i have been playing with motul 300v which is a 3 ester fully synthetic oil 15/50 egine oil,so far it has been alot better i.e shift and noise plus temps are down a few '0c!!!!! indicating less friction.

The Texaco MTF would technically be the same viscosity grade as a 0W30 motor oil and close to a 5W30.

See here

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My 2p worth... And you can consider this as a reply to the same topic elsewhere. :)

The reasons for these low viscosity oils are two. One is because the oil pump can't handle a high viscosity oil in cold climate.

The other one is the construction of the gear syncros, mainly second gear. The syncro rings need to grip on the gears and when the oil is too thick it can't "escape" quickly enough and there will be grating when shifting.

Mineral based ATF is fine for these reasons and it was the oil that was available at the time when LT77 was launched. But it has rather poor lubricating properties so there have been newer oils developed over time with better properties.

The viscosity, in transmission oil terms, is in the region of 70W up to 80. And there are several brands to choose from, where MTF94 is the one Land Rover is recommending.

I personally use Redline MTL in my LT77 and is quite happy with that. ;):)

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I once measured the 'viscosity' of various oils by letting the same amount of oil drain through a hole. The amount of oil and the size of the hole don't matter as they were the same for all oils. The results were ATF: 12 seconds, MTF: 15 seconds, Castrol VMX: 20 seconds and EP90: 80 seconds.

This was mainly to show that MTF was much thinner than VMX. The 'experiment' was done at 20c.

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Good experiment Jim, that would give you a good idea of the kinematic (density dependant) viscosity of the oil at the temperature you did the experiment at.

Only problem is - you didn't mention the temperature? And the other problem is that different oils often have a different rate of change of viscosity with temperature (of course you gat a little bit of info from the viscosity specs - but I don't think you can get the slope of the viscosity curve from that).

If anyone is really interested in knowing for sure, we have a good rheology department here, so I could probably get some testing done if someone wants to send me some (clean, new) oil samples. Need about 50-100ml to do the tests at a few different temps.

Edited by isuzurover
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I used MTF-94 last time (ATF previously).

I'm interested in good alternatives as well.

Hi everyone. I'm new to the site but I picked up the following info posted by the difflock people on another sit so I thought I'd include it.

"5-speed LT77 and R380 main gearbox (Land Rover 90 & 110, Discovery, Range Rover)

Firstly, let’s deal with the somewhat notorious LT77 and R380 5-speed main gearbox. These are famed for a poor, notchy gear change, especially from 1st to 2nd gear.

The notchy gear change is due to a combination of a weak synchromesh and the use of a plain mineral ATF fluid.

ATF was originally specified for the LT77 5-speed gearbox and, theoretically, could be used in the later R380 box. Type DIII is the best grade currently available. ATF was originally specified because of the weak synchromesh in the LT77 and R380 boxes (especially second gear).

ATF has a very low viscosity (rated as 5W20 since it falls below normal gear oil viscosity grades) and so it has minimal drag on the gears, enabling the weak synchromesh to do the best of a bad job.

BUT ATF has several drawbacks which is why it is NO LONGER recommended for use in such boxes. These are:

It is generally a plain mineral base stock formulation (even DIII) and this, coupled to its very low viscosity, means that it is poor at preventing metal to metal wear in manual transmissions.

This is compounded by the fact that the viscosity improvers within (thickeners) are more rapidly sheared down in manual transmissions. Again, this reduces the protective film strength of the ATF in those areas of high pressure contact and also increases transmission noise.

ATF thickens as temperatures drop (increasing that drag on the gears) which is why folks notice that gear changes are worst on cold mornings and improve after a few miles motoring when the ATF has warmed up a little.

So, what are the alternatives?

Land Rover currently has commercial arrangement with Texaco/Chevron that leads it to recommend a Texaco/Chevron MTF94 fluid. From the freeback we have received and read on this Forum and elsewhere, we feel it’s a little too viscous (5W30 or 70W80) to give the best results. Nonetheless you should use it in preference to ATF if your choice is limited to the two.

However, there are better alternatives such as the fully synthetic MT75D gear oil we have developed. Rather than simply plug our MT75D I’ll give pointers to what you should look for when seeking alternatives to ATF or MTF94.

Firstly, the lubricant must have the original 5W20 low viscosity of ATF fluids to give minimum gear drag. However, it MUST also be formulated only from fully synthetic base stocks since these will have a much higher lubricant film strength so as not to be squeezed out of those all important high pressure contact areas where wear might occur. This, and the low viscosity, has the added benefit of reducing friction which lowers transmission noise and improves economy.

It must also be highly shear stable and able to maintain its optimum working viscosity over a very wide temperature range. This and a very, very carefully matched coefficient of friction (probably the most critical parameter) will ensure that it dramatically improves gear shifting in LT77 and R380 boxes (especially from cold).

It is the improved shear stability and higher film strength that enables synthetic gear lubricants to outlast their plain mineral counterparts by up to 5 times. However, we err very much on the cautious side and recommend only a doubling of drain intervals.

Note that unlike engine oils, gear oils do not have combustion by-products building up in them, nor do they suffer the higher temperatures of engines, so extending drain intervals is entirely acceptable if the lubricant is of the highest performance and the increase is modest. The exception to this would be if the gear oil were contaminated, perhaps by water or mud during deep wading, though this is unlikely. If the oil is contaminated in this way it MUST be changed immediately, regardless of its formulation.

LT230 Transfer Box (Land Rover 90 & 110, Discovery, Range Rover)

That’s the problems of the LT77 and R380 boxes solved, but what about the LT230 transfer box to which these are commonly mated?

You should NOT use ATF, MTF94 or MT75D in an LT230 TRANSFER box. It must use a thicker gear oil such as EP90 (monograde), EP80W90 (multigrade which is better for cold starting lubrication on winter mornings) or EP75W90 (typically fully synthetic giving the best lubrication of all). This is the same lubricant that you should use in your axles and you should look for an API GL5 specification for best protection."

I'm sure there is a little commercial interest in their writing but I hope there is some useful stuff there as well.

I'll see you Tuesday Chris.

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As I commented on the other thread I have just put Difflocks MT75 in my manual box and I was underwhelmed (had MTF94 in there before, I have also used Dexron type oils in my older 90's gearbox)

Not worth 10x the price IMHO, cold change is a bit better (as per the claims) but the downside is the hot shift, particularly when very hot, seems a bit worse (though there really isn't much in it). I'd rather have a grumpy gearbox first thing in the morning than a grumpy gearbox the rest of the time :huh:

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Here's the list of alternatives to MTF94:

redline MTL

shell spirax GSX

castrol systrans, sMx-s, vMx80

Mobil Mobiltrans shc30

Agip rotra FE

Elf tranself trZ

penrite manual gear oil xtra light

q8 t60

I went into the LR garage, who said "MTF is for TD5, not LT77 — ATF is for LT77. Besides, MTF is engine oil"!

then when I insisted [saying LR had changed the spec. for LT77 post-production], showed me "this is MTF" [clarified as "this is what we put in when we're supposed to put MTF in"] producing a sample of 10w40. When I suggested there is an original LR part that is Texaco MTF 94, they looked at me as though I were speaking a foreign language :lol:

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I went into the LR garage, who said "MTF is for TD5, not LT77 — ATF is for LT77. Besides, MTF is engine oil"!

As I have said before, the normal LR mech is illiterate. WTF do they think 'MTF' and 'ATF' mean?

Maybe you should tell them that the box takes WTF instead :rolleyes:

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  • 3 years later...
Iam gona change the oil in my main gearbox in my td5 which type of oil is best? Iam more confused than ever after reading this topic :wacko::lol: I carnt seem to find anywhere what stocks mtf 94 localy.

I can recommend using Amsoil synthetic gear lube 75w-90 in difs and transfer box and their ATF in LT77 gearboxes.

Its not cheap at around £13 for just under a litre but it has avery long service life, its been in my 90 for nearly 50000 miles! My boxes and diffs have all now done 140000miles. Gearchanges always been easy even from cold.

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I'm using ATF in my R380. To keep the viskosity, but to upgrade the friction properties I've blended it with 5g/l tungstendisulphide powder (WS2) (0.6 micron). Temperature down and some improvement to before (ATF only). So far no Problems after 7000 miles.

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I get my ATF for nothing so guess I will be putting that in rather than the expensive MTF!!!

Western how often did/do you change the ATF in your R380?

I have just looked on texaco's website they dont even have MTF 94 listed!

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