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redrob
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Am in complete agreement with Anchorman. Straight (mono-grade) oils are expensive, as they have to be brewed to stay "in grade" whatever the operating conditions. 75W-90 is 75 when cold, and 90 when hot, and 90 is rather heavy (in my experience) for many tight-tolerance modern boxes, especially in the winter.

Gear oil is commonly available as 75W-90, 75W-85 and 75W-80 . . . and there is quite a difference in viscosity between 80 and 90. To avoid the (probably unnecessary) expense of a straight 75 (75W-75!!!), even if you can find it, 75W-80 is a good choice. I've just bought 5-litres of it (GL-5 spec) for 30EUR, which isn't prohibitive.

Chris Gregory

I'm confused ?? Anchs is saying straight 75 grade.. You are saying 75/80 ?? If the lowest number is the minimum viscosity how can it help ???

If You were saying something like 65/ 80 so the oil would be thinner I could understand that. But putting in 75 with a higher number following just doesn't add up ...

Wee Charlie.

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Hi Charlie,

Toyota specify 75W-90 for the RAV gearbox. This is a multigrade gear oil. All multigrade oils have these two sets of figures, eg 10W-30, 20W-50, 0W-30 etc etc. What do the figures mean?

They are a measure of how an oil will perform when cold and when hot. The first figure (eg 20W) says that the oil will behave, so far as viscosity is concerned, like a 20-grade (ie thin/lightweight) oil in Winter (ie when cold). This helps cranking, initial circulation round a cold engine or gearbox and minimizes the stresses of first-off cold running.

As oil heats up, the viscosity will drop (the oil will become thinner), and to prevent this, "viscosity index improvers" are added to the oil to keep its viscosity up at higher temperatures. If only modest amounts of "VII" are added during manufacture, then, for example, a 20-grade oil might be able to simply retain its viscosity, and so it might be a 20W-20 (or "straight 20"). By adding more VIIs, the viscosity can actually be persuaded to RISE as the temperature increases. So, we might see a 20W-50. Twenty when cold (good for starting and cold running) and 50 when hot (what the engine needs at normal temperatures, or when working hard).

So, our Toyota gearbox oil is specified as 75W-90. Nothing wrong with this, but, in colder climates many owners (and this isn't limited to Toyota) find difficulty in (i) engaging 1st and often reverse, and (ii) changing from 1st to 2nd. As the box warms up (or is used in warm conditions), the oil takes on its 90 viscosity, and, to many owners, this just seems too thick to allow effortless gearchanges.

One widely used solution has been to run modern 5-speed boxes not on traditional gear oil, but on Manual Transmission Fluid, which is specifically designed to overcome all these problems. Use of such fluid has a long, long history in boxes (particularly from ZF) used in numerous vehicles since the 1980s. It has all the qualities required, including EP (extreme pressure) additives to keep metal from metal between the gear teeth surfaces.

However, the RAV4 is not only a 5-speed box, but is also a Transaxle - ie it contains the differential for the front wheels. Because of this, several of us are reluctant to advise moving too much away from Toyota's requirement for a gear oil (rather than transmission fluid).

So, if you need something "a bit less viscous", go for 75W-80 gear oil (meeting GL-5 spec). The 75 isn't the problem; the 90 is (for some).

Sorry if I've gone on a bit, Charlie, or put down things you already know. Do put me right, Guys, if I've slipped up anywhere.

Chris

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So are you saying these gearboxs are notchy when warmed up? And not from cold?

There seem to be complaints about both. Agree with your drift: when cold, a 75W-80 and a 75W-90 ought to behave the same. But, in practice, this doesn't seem to be so. I've had my own box filled with -90 (following a DMF and clutch job), and the notchiness was quite unacceptable. Simply refilling it with -80 instantly improved the shift no end right across the temperature range. My local transmission specialist reports this is a common experience, across many makes of vehicle.

Chris

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So are you saying these gearboxs are notchy when warmed up? And not from cold?

Thank You !! Brilliant description !! I already understood the viscosity ratings..

What I did not understand was the the benefits or replacing a single viscosity oil of 75W with an oil of 75W80 unless its purely based on cost ??

Would I be right in saying that both oils will start off at 75W ??

I thought to improve the gear change when cold would have meant going down with the bottom number ?? IE 60 or 65 ??

When I was in business up till a couple of Years ago I had several of the latest model Ford Transits.. The first to second gear change on some but strangely not all was that bad when cold that some of the Drivers used to pull away in second gear..

The ratios on the Rav 4 or at least on My T180 would not allow this though.......

Interesting topic !!

Thanks

Wee Charlie.

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So are you saying these gearboxs are notchy when warmed up? And not from cold?

Interesting topic !!

And, just to court yet more comments, I've found this on Castrol's website:

Castrol Syntrans Transaxle 75W-90 (manual transmission fluid)

See http://www.castrol.com/liveassets/bp_internet/castrol/castrol_uk/STAGING/local_assets/downloads/c/cas_specialities_car_product_brochure.pdf

It's the last item in Section 5 (grey) in this product catalogue.

It seems to be 75W-90, GL-4, EP, made for transaxles, etc etc etc - all that Toyota might want?

I have used one of its earlier stablemates, Castrol SMX manual transmission fluid, for years now, in several 5-speed boxes that were notchy or cold-baulky, and it solved all the same problems some of us have now. I'm due for a 'box oil change shortly (my 5th gear needs replacing) and will probably try the stuff, 75W-90 notwithstanding. Will report back.

Chris

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Am in complete agreement with Anchorman. Straight (mono-grade) oils are expensive, as they have to be brewed to stay "in grade" whatever the operating conditions. 75W-90 is 75 when cold, and 90 when hot, and 90 is rather heavy (in my experience) for many tight-tolerance modern boxes, especially in the winter.

Gear oil is commonly available as 75W-90, 75W-85 and 75W-80 . . . and there is quite a difference in viscosity between 80 and 90. To avoid the (probably unnecessary) expense of a straight 75 (75W-75!!!), even if you can find it, 75W-80 is a good choice. I've just bought 5-litres of it (GL-5 spec) for 30EUR, which isn't prohibitive.

Chris Gregory

Not that expensive for a straight 75w gear oil... http://www.opieoils....ission-oil.aspx

Or this... http://www.opieoils....g-gear-oil.aspx

Or this... http://www.opieoils....g-gear-oil.aspx

Both the Silkolen and Fuchs oils are exactly the same but in different bottles but a different price.

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Very interesting story line and fascinating reading (I must have missed this one). One thing that bugs me a little bit is the thread was started by Redrob and Craig Simpson who really got their teeth into it but 12 months on we have never heard from either if they finally got a solution to their respective problems!!!!

Regards Clare

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Very interesting story line and fascinating reading (I must have missed this one). One thing that bugs me a little bit is the thread was started by Redrob and Craig Simpson who really got their teeth into it but 12 months on we have never heard from either if they finally got a solution to their respective problems!!!!

Regards Clare

Perhaps They were not so tenacious as the New Breed of discerning Rav owner ????................................. :yahoo: :yahoo:

Wee Charlie.

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Well actually the 6 speed box in a 4.3 should be filled with a straight 75W GL4/5 oil;

2006-2009 models.pdf

I think also that £41.70 for a gallon of oil plus delivery is expensive. I must admit I've never seen it in other than a Toyota tub before.

It is interesting that the viscosity scales for engine oil and gear oil are different. 75 gear oil is like olive oil in consistency.

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How many ltr does the box take? My Avensis takes near enough 3ltr of the stuff. I dont mind spending that kinda cash when is an ester oil tbh...

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I will ask again as My question seems to have got lost

Is there any gain in getting the oil changed for oil exactly the same as what is in there ??

Would Castrol Syntrans B 75W with the following claims be a better or worse bet ??

Fuel Efficient

manual Transmission Fluid

Smooth shift at low temperature

APPLICATION:

FOR CARS REqUIRING ZF TE-mL 11

AND SUPERIOR LOw TEmPERATURE

ShIFTABILITY

Full synthetic fluid approved according ZF

TE-ML 11 for use in BMW passenger cars and

highly stressed inline manual transmissions.

Or perhaps Castrol Syntrans FE 75W

Fuel Efficient

manual Transmission Fluid

Smooth Shift – Fuel Efficiency

APPLICATION:

FOR mOST APPLICATIONS REqUIRING

API GL-4 - APPROvED FOR FORD mODELS

REqUIRING wSS-m2C200-D2

A full synthetic transmission fluid

recommended for most passenger car

conventional manual and “dry clutch”

transmissions where API GL 4 lubricants

are required. It is approved suitable for use

where Ford WSS-M2C200-D2 is specified.

• Ford Focus, C-Max, Mondeo, S-Max,

Galaxy, Transit.

• Volvo => C30, S40, V50, S60, V70, C70,

XC60, XC70.

FEATURES AND BENEFITS

• Low viscosity synthetic formulation

offers the potential for fuel economy

benefits while maintaining excellent wear

protection.

• Extremely good cold flow properties

provides added protection on start up and

improves shift quality.

• Excellent frictional characteristics extends

synchroniser life and improves shift

comfort.

• High shear stability maintains performance

over the lifetime of the lubricant.

• Excellent high temperature stability

maintains transmission cleanliness

prolonging the life of transmission and

lubricant.

Or am I just best leaving alone ?? I will need to get the car serviced either on My next trip south next Tuesday or the trip after at Christmas...

If its a good idea to change the oil I will get it done with the service.

I will get the Service carried out at Westlands Toyota who were brilliant when doing My engine change..

Thanks.

Edit.. Car booked for service next Wednesday afternoon....... :thumbsup:

Wee Charlie.

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Hi Charlie,

I've also looked at Castrol's descriptions of their Syntrans B75W and FE75W. Both appear to be for regular 5-speed boxes (from two vehicle manufacturer groups), but make no mention of being designed for MANUAL TRANSAXLES, which is what our RAVs have. Our transaxle contains not only the 5-speed box, but also the hypoid differential for the front wheel drive. (The separate transfer box takes the drive off to the rear wheels.)

Hypoid (diff) drives are subjected to huge 'spot' pressures between their crownwheels and pinions, and they normally require EP (extreme pressure) additives to keep metal from metal.

It's possible that the B75W and FE75W oils have this quality, but you'd have to ask Castrol (who are pretty helpful on the phone, I remember).

BUT, they also list, in their downloadable pdf catalogue: Castrol Syntrans Transaxle 75W-90, which is specifically designed for transaxle use.

I'm going to try this first, even though it reads 75W-90. I've used Syntrans before, and it's good. It will be a couple of weeks, though, before I can put it in the RAV.

Chris

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Thanks Chris.. I had noted the word Hypoid but did not know what it meant !! Best just leave alone this service I think.......

Thanks again.. Great information !!!

Wee Charlie.

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Whenever I buy a used car I always change all the fluids (Apart from the coolant if the test shows its okay) and the filters. I found the box oil (Avensis T-180) to be quite an easy job and after meeting and chatting to Anchs he advised me that a straight 75w grade should be used. I understand that they have a triple syncro in these types of trans. So I did the search on the net and found (What I believe to be) the Fuch's/Silkolen ester based fluid to be the top spec as there didn't seem to be a lot of choice when it came to a straight 75w grade from the majors.

I found that befor I change the box oil that it was difficult in the cold to select 1st gear and 2nd always crunched untill the oil warmed up. I know find it much better to select 1st and the 2nd gear crunch very rarely happens anymore.I think the benifit that anyone would find is that you know that the box has the correct oil and quantity so you know that you are protecting a piece of the car that if goes wrong would cost a small fortune to put right. So I sleep well at nights as a result of that.

I dont think it makes much of a difference to mpg in changing the oil but at least you know its been done. I had an Audi A6 3.2 quattro so thought I'd check the box oil only to find that it was low. No signs of any leaks so drained and renewed it. My Polo TDi was the same, low on oil but as dry as a bone without any leaks. So renewed that also. Now people say that a box cant use any oil but with the absence of any leaks I'm at a lost to whey it was so low. It also smelt like cats wee when it was drained which I'm told that its lost some of its protective qualities...

Btw... I contacted 2 main dealers regarding the oil grades and both told me it was a 75w-80 which is completley wrong!

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I will get the Service carried out at Westlands Toyota who were brilliant when doing My engine change..

Wee Charlie.

Which branch of Westlands? I bought my wife's RAV and my Aygo from Stourbridge and plan to use them for future services.

David

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Charlie

The transmission oils get changed on the big (even number) service and although the gearbox only gets "inspection and tp up" it might be better to leave it this time as they will have all the underside covers off next time. The negotiate a price for the oil change.

To answer your question, I doubt that you will notice any change by having the oil changed but it might flush out any particles or condensation moisture that may have formed over the years.

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  • 2 weeks later...

I would be cautious with the Fuchs Titan SRG75 (same as previous Silkolene Pro SRG), because the product spec does say "Not suitable for hypoid applications". The RAV's box is a transaxle, and this contains a hypoid differential (for the front wheels).

Chris

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I would be cautious with the Fuchs Titan SRG75 (same as previous Silkolene Pro SRG), because the product spec does say "Not suitable for hypoid applications". The RAV's box is a transaxle, and this contains a hypoid differential (for the front wheels).

Chris

Now that is a good point about the SRG oils. My car is an Avensis T-180 so I contacted Opie Oils and they did say that this oil was perfect for my gearbox! But I'm guessing that the RAV has a different set up yp the Avensis as its 4x4? You've just started to make me think now so I've email Opie to make sure I've not used the wrong oil. I know they list Fuchs TITAN SINTOFLUID FE SAE 75W synthetic manual transmission oil for my car but I wanted to see if the SRG was also okay...

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I would be cautious with the Fuchs Titan SRG75 (same as previous Silkolene Pro SRG), because the product spec does say "Not suitable for hypoid applications". The RAV's box is a transaxle, and this contains a hypoid differential (for the front wheels).

Chris

Okay............ Just had an email back from Opie Oils and SRG is fine for an Avensis but doesn't look like its any good for the RAV boxes like you said because of the Hypoid transaxle

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I would be cautious with the Fuchs Titan SRG75 (same as previous Silkolene Pro SRG), because the product spec does say "Not suitable for hypoid applications". The RAV's box is a transaxle, and this contains a hypoid differential (for the front wheels).

Chris

Okay............ Just had an email back from Opie Oils and SRG is fine for an Avensis but doesn't look like its any good for the RAV boxes like you said because of the Hypoid transaxle

Good info Thanks for sharing !!............................ :thumbsup: :thumbsup:

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The Avensis 6 speed (E64) is the same box as a RAV. It just has a closure plate where the transfer box bolts on.

There is no requirement for an EP oil in the E64 box.

E64.pdf

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The Avensis 6 speed (E64) is the same box as a RAV. It just has a closure plate where the transfer box bolts on.

There is no requirement for an EP oil in the E64 box.

E64.pdf

many thanks Don for the pdf file and clearing this question up.:thumbsup:

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