Gearbox oil argument!

cwc said:

I changed from MTF to Difflock evo 1 in my TD5 box its so slick now, and being fully synthetic is got a long change interval.
Just so bloody expensive
David

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I agree David. I put Evo1 and Evo2 oils in a TDi 200 we used to have and she ran beautifully. Cost me about £100 at the time but she did run well

I put MTF in mine and it runs beautifully too (and costs less than synthetic). I can't see any advantage in synth, and the cost is greater.

paul_c said:

I put MTF in mine and it runs beautifully too (and costs less than synthetic). I can't see any advantage in synth, and the cost is greater.

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The advantages I enjoyed when I did the 200 was easier running, lower friction, lower noise, better mpg.

thebiglad said:

The advantages I enjoyed when I did the 200 was easier running, lower friction, lower noise, better mpg.

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Compared to the old oil, or compared to MTF?

paul_c said:

Compared to the old oil, or compared to MTF?

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Hi Paul, it was a TDi 200 with the LT77 box so it never had MTF anyway, but my comparison was with fully synth in the main gearbox, tranny box and both axles - (so the friction in the whole drivetrain was reduced) as opposed to std mineral oils.

I have a 2001 Td5 with 213K on the clock ( 166K when I bought it ).
Last Sept box began to get noisy - felt sure it was front bearing in the box .
Decided to try an oil change - had enough Evo 1 and Evo 2 to go around (diffs/transfer/main).
No change for first day or two - then box quietened down and has been fine since . So have to credit the EVO .
Over the years I have read a lot of articles about oil and how oils are formulated and matched to what they are to do . For example gear oil and engine oil have very different properties (e.g. EP for extreme pressure found between gears when they mesh )
*Therefore it never made sense to me that ATF should be used in a manual gearbox . It was suggested that LR recommended it because ordinary gear oil prevented the synchros from matching the gear speeds and allowing smooth changes .
* I also never used oil additives - a good oil doesn't need them and they can do more harm than good IMHO.
* Mixing grease and oil would suggest getting the worst of both worlds.
* I have also noticed that friends of mine who were used to older machinery for example are causing themselves many problems with newer tractors etc due to their attitude of " any oil is better than no oil " and " the cheaper the better. "

Hello to all, I work for an oil company so i know me stuff, Right first thing oil comparison

Viscosities

ATF DII @ 40'c = 36
@ 100'c = 7.5

MTF 94 (75/80)
@ 40'c = 58
@ 100'c = 10.6

Evo2 Oil (Fully Syn EP 75/90)
@ 40'c = 95
@ 100'c = 15.6


I have just changed the oil in my R380 gear box with a mix of 2L of Evo2 and 700ml of MTF 94, when i drained the oil it had a red tinge so must have been ATF in there before. Typical hedgehog formed on the drain plug, for me it has to be Fully Syn all the way because of the better caracteristics of the oil, extra gear protection etc. Since i have changed it there is less noise and smoother gear change & easier to get into reverse. IMHO if you can afford the good stuff go for that it will pay off in the long run ATF is a tad thin at higer temps to offer a good film of oil around the gears to give you the protection you need. Any more questions feel free i will be happy to try and answer them.

Pyper28 said:

Hello to all, I work for an oil company so i know me stuff, Right first thing oil comparison

Viscosities

ATF DII @ 40'c = 36
@ 100'c = 7.5

MTF 94 (75/80)
@ 40'c = 58
@ 100'c = 10.6

Evo2 Oil (Fully Syn EP 75/90)
@ 40'c = 95
@ 100'c = 15.6

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Those figures would suggest to me that Evo2 oil is too thick for the gearbox. Whether it has an adverse effect, is debatable though. I'd have thought churning around thicker oil would reduce, not improve, fuel economy for one thing.

Yes indeed a larl thick thats why i thinned it out a litre of MTF but its summer and the ambient temp is up so i going with that for now and them come autumn drop back to 2 litres of MTF and 670ml of Evo2.

paul_c said:

Those figures would suggest to me that Evo2 oil is too thick for the gearbox. Whether it has an adverse effect, is debatable though. I'd have thought churning around thicker oil would reduce, not improve, fuel economy for one thing.

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That's why you don't use it in the main gearbox, just in the Tranny box and axles.

For the main box you would use EVO1.

Incidently, what do these numbers represent, as they don't tally with recognisable visocities?

thebiglad said:

That's why you don't use it in the main gearbox, just in the Tranny box and axles.

For the main box you would use EVO1.

Incidently, what do these numbers represent, as they don't tally with recognisable visocities?

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MTF94 is £6.75/litre
Evo1 is £16.98/litre (that's 2½ times as much)

The website claims it outlasts ATF by 2-3 times. So really, there's no saving to be made, just the indirect cost by not needing to change so often. With the synthetic oil needing to remain in the gearbox for over twice as long, in years 2 and 3 there's no technical benefit to be had anyway.

I think I'll stick with the recommendation, at the recommended intervals, rather than going for synthetic + extended changes.

thebiglad said:

That's why you don't use it in the main gearbox, just in the Tranny box and axles.

For the main box you would use EVO1.

Incidently, what do these numbers represent, as they don't tally with recognisable visocities?

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Recognisable Viscosities? ATF is like Hydraulic Oil 32 is that the kinda thing you mean, and does anybody know what grade EVO1 as no info on difflock as i can compare that into the results as well. I will blend the most suitable oil and try this and compare MPG

Pyper28 said:

Recognisable Viscosities? ATF is like Hydraulic Oil 32 is that the kinda thing you mean, and does anybody know what grade EVO1 as no info on difflock as i can compare that into the results as well. I will blend the most suitable oil and try this and compare MPG

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I took it to mean a viscosity number with units, eg Pa s

****e the bed forgot that, them measurements are in cSt Paul

Anyone that starts a comment on a thread with:

"Hello to all, I work for an oil company so i know me stuff " - is really asking to be shot at big time, but I'm resisting the temptation for now.

What I was referring to is the fact that you quote viscocities at 40° and 100° as per the norm, but those figures seem to bear no relation to the product names ie EP 75-90?



As you will know I'm sure there are a vast range of EP 80-90 oils available and when looking at their viscocities as above, they range hugely, so i can't help wondering what is the point of the motor manufacturers recomending for example EP80-90 for a particular application when we know that the actual operating viscocity could be nearly anything !!!!!

IF they were to say an EP oil which has the characteristic viscocity of for example: 80 @ 40° & 25 @ 100° (figures plucked out of the air as per the TBL method of oil testing) then that would demonstrate a clear need for a specific oil. As it is, the particular application, (a transfer box for example) according to the vehicle manufacturer can run succesfully on just about any EP oil, so long as it is (in the case of LR) to GL5 spec.

This all leads me to conclude that it is not at all neccesary "to know your stuff" when it comes to oils, but just have a broad enough 'feel' for the subject to appreciate that it is not anywhere near as critical an issue as some would have us believe.

Changing oils regularly however does, imho, have a crucial impact on wear of assemblies.

thebiglad said:

you quote viscocities at 40° and 100° as per the norm, but those figures seem to bear no relation to the product names ie EP 75-90?

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They do though. First of all to correct your spec, it would be 75W90. And the 2 numbers do correspond to a real world viscosity (SAE J306 classification):

https://www.opieoils.co.uk/pdfs/gearoils.pdf

SAE J306 Specifications - The Lubrizol Corporation

(Plenty more if you Google SAE J306)

thebiglad said:

As you will know I'm sure there are a vast range of EP 80-90 oils available and when looking at their viscocities as above, they range hugely

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The don't range hugely. There is a band of viscosities which determine the grade, but they don't range that greatly.


Viscosity is important but its not the only consideration in a gear oil. What doesn't help, is the ATF, MTF94 and Difflock EVO1 don't have published viscosities, making them difficult to compare - we have to take the above post's viscosity figures on trust (and without units, or a source listed....who knows??)

hi chaps, go on to the ashcrofts web site they recommend mtf for the r380 no vote reqd.cheers.

thebiglad, i dont mind being "shot at" i didnt say i was wikipedia of oils just trying to give people a basic understanding on which oil is most suitable, EP 80w/90 has a rough (Kinetic Vis) of 140 cSt @ 40c, this is the viscosity band of 80w/90 (usually give or take -5 or +5) as for EP 85w/140 has a KV of around 360 cSt @ 40c
i know this from experience but a PDF is here for you to read http://www.valvoline.com/pdf/High_Performance_Gear_Oil.pdf

I am just trying to determin the optimal grade of oil to use in the gearbox based on price per litre, protection qualities & gear change ability so that other people can try & save money and time by reading this thread based on all our experiences with different types of oil.

to carry this on i find that atf works better, mtf94 gives poor gear changes, and never tryed difflock evo because its to expensive what should i do is difflock evo the dogs balls and i must do or is there some thing better/cheaper

i do understand that atf is in no way recomended for the later r380 box but i find it best but maby because my box is *****d because of useing atf (was in it when i got it +25K)

martinhollings said:

to carry this on i find that atf work better mtf94 to give poor gear changes and never tryed difflock because its to expensive to try what should i do is difflock evo the dogs balls and i must do or is there some thing better/cheaper
i do understand that atf is in no way recomended for the later r380 box but i find it best but maby because my box is *****d because of useing atf (was in it when i got it +25K)

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I can't really understand fully what you're saying, but if your transmission oil has been in the box for 25,000 miles, then its overdue a change - the service interval is 12,000 miles or 12 months, whichever is sooner.