75W90 VS 75W85 GL-4 in Toyota

[zmelli]

Here is the dilemma, I have a Corolla XRS with the Aisin C64 6-Speed Trans. My manual states that I can use 75W90 GL-4/GL-5 oil in it.
After many hours of research I decided to stick with GL-4. I simply do not trust Manuals or dual rated oils. Manufactures simply do not look out for the consumers only the bottom line. you cn thank Wall Street for that!

I am running 75W90 Motorcraft XT-M5-QS. Made Germany , but it is pricy. Castrol Syntorq LT 75W-85W GL-4 (GM# 12346190)is also a sub but is super pricy and thinner that what the book calls for?

I do know that there are 75W85 GL-4 oil that I can use that are half the price! The oil I am considering is the off the shelf Nissan OEM Manual Transmission Fluid MTF 75W85 For half the price. Do you think I would be fine with the 75W85?

 

[Rand]

That oil is considerably thinner(at 100c).

it should be ok usually unless you tow or get the transmission very hot.

there are several other options like redline that work also.

 

[SOHCman]

I can recommend Redline GL-4 MT-90 (75w-90), its about $9 a quart depending where you get it. Its all I use in my toyota. Before I knew better I tried a duel rated oil and a straight gl-5 (mobil one 75-90) and both shifted like [censored]. You need the gl-4 for proper syncro function... Amsoil also has a good gl-4 offering.

 

[zmelli]

Originally Posted By: SOHCman
I can recommend Redline GL-4 MT-90 (75w-90), its about $9 a quart depending where you get it. Its all I use in my toyota. Before I knew better I tried a duel rated oil and a straight gl-5 (mobil one 75-90) and both shifted like [censored]. You need the gl-4 for proper syncro function... Amsoil also has a good gl-4 offering.

I have used the Amsoil GL-4, but after a while the shifting started to get stiff, I can not recall how many miles I put on the oil. When I switched to the Motorcraft is was like butter, I was amazed. I have about 30K on the Motorcraft and now I am having trouble putting it in 2nd gear when it is cold in the morning (35-50Deg/F) This is why I was going to replace it. I was tempted to try the Redline but for some reason I went with the Amsoil over the redline last time. I am sure I gave that decision a lot of thought.

 

[zmelli]

Originally Posted By: Rand
That oil is considerably thinner(at 100c).

it should be ok usually unless you tow or get the transmission very hot.

there are several other options like redline that work also.


I was wondering if Toyotas rec was based on Dino oil and if you can get away with a 85W if you use a synthetic? I do not think I was able to confirm if the Nissan MTL was a synthetic. I think all the Japaneese mfrs are using the same 75W85 from the sme supplier.

 

[m37charlie]

Living in California, I do not know why you want a thinner oil than specified by the mfg.
Redline MT90 is GL4 and is easily available.

Charlie

 

[zmelli]

Originally Posted By: m37charlie
Living in California, I do not know why you want a thinner oil than specified by the mfg.
Redline MT90 is GL4 and is easily available.

Charlie


Many mfg have changed from 90w down to 85w and I think this may be due to advancements in the Lubes. I would need to see what a newer Toyota manual has listed. Thicker oil may actually run hotter than a thinner oil. But film strengh is another factor. Dealers usually throw in Bulk GL-5 if you ask them! go figure.

 

[zmelli]

I think I need to phone the Lotus shop and get some Castrol TAF-X.
This has been approved (backed by extensive testing) for use in my Aisin C64 Transmission. The one size fits all thinking simply does not apply anymore.

 

[zmelli]

Originally Posted By: zmelli
I think I need to phone the Lotus shop and get some Castrol TAF-X.
This has been approved (backed by extensive testing) for use in my Aisin C64 Transmission. The one size fits all thinking simply does not apply anymore.


This issue raised it's head 1-2 years ago in Australia, Lotus contacted Castrol UK and the Castrol Syntrax 75W-90 is not the same as Castrol TAF-X 75W-90.

TAF-X is the only oil Lotus have tested that will stand the extreme crown wheel and pinion pressure and smooth synchro mesh operation, there are better oils available for individual components but for a transaxle operation when one oil has to withstand both operations TAF-X was the solution, tested and approved by Renault/Lotus.

There has been no further testing of new blend of oils today and no plans in the future. This would only occur if TAF-X was no longer available. The original oil was Mobile 630 M, Mobile discontinued the M version of 630 and it was then we went too Castrol TAF-X which had been specifically developed for another application and proved suitable for the Renault Transmission and our application.