Fuchs Titan Sintofluid FE SAE 75W GL4 vs “” 75w80 GL5

[RocksForsSale]

The recommend fluid for our MT trans is from Fuchs is the 75w80 gl5 for the part number.

I bought the FE gl4 and installed.

Does it matter?

[LJS]

Your 1-2 sycro's MAY not like that fluid....
Google GL4 vs GL5 gear oil---you'll find it informative an a bit confusing....
IMHO I would drain the stuff and replace it with the GL5 gear oil
YES that's an expensive redo but I believe a necessary one.
FWIW- I made the same "error" back when I first changed my gear oil---Purchased the GL4 by mistake and replaced it with FUCHS TITAN SINTOFLUID SAE 75W-80(synthetic) GL5 Fluid....Still have those damn jugs in the garage....

[RocksForsSale]

I searched… came up with this stuff is too thin.
I’ve been driving easy, but it’s been hot. My box was noisier than before (bearing noise), but I went 4:1 from RWD.

ECS listed this ok. The customer support said it’s ok. Fuchs changed numbers, but get it out ASAP and sent me out three bottles of MT-90.

What is really confusing is this Fuchs Titan Sintofluid FE 75w I put in is GL-4. I thought this was the recommend one.

[RocksForsSale]

Your 1-2 sycro's MAY not like that fluid....
Google GL4 vs GL5 gear oil---you'll find it informative an a bit confusing....
IMHO I would drain the stuff and replace it with the GL5 gear oil
YES that's an expensive redo but I believe a necessary one.
FWIW- I made the same "error" back when I first changed my gear oil---Purchased the GL4 by mistake and replaced it with FUCHS TITAN SINTOFLUID SAE 75W-80(synthetic) GL5 Fluid....Still have those damn jugs in the garage....

Everywhere I saw old was go GL4+… then GL4/5 doesn’t matter because of regulations. I don’t know.

How long did you drive it?


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[LJS]

That's interesting----The RED LINE stuff is also a GL4 oil
I didn't put the GL4 oil in the gear box.....saw the issue when I about to drain the oil. Stopped and purchased the "correct" oil...

[RocksForsSale]

But it’s thicker 75w90. I thought the “FE 75w”was very thin. I guess you never put it in and I did.


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[RocksForsSale]

That's interesting----The RED LINE stuff is also a GL4 oil
I didn't put the GL4 oil in the gear box.....saw the issue when I about to drain the oil. Stopped and purchased the "correct" oil...

Well ECS listed it as OK… so blissfully ignorant. Thought my trans was noisy. I hope I am not SOL.


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[LJS]

Lots of guys use the MT-90 oil with no issues- I would change it once you receive it....keep the driving to a minimum and no banging gears....

[RocksForsSale]

Lots of guys use the MT-90 oil with no issues- I would change it once you receive it....keep the driving to a minimum and no banging gears....

I’ve been driving it carefully. But it did feel a little notchy. What has me concerned is the audibleness of the bearings. Accel wu wu wu, decel wuuuuuu. Not bad bad but audible isn’t good.

@100C 6.3 - G052726A2 or Fuchs Titan Sintofluid FE 75w

@100C 14.2 - G052-911 factory or Fuchs Titan Sintofluid 75w-80

That’s a pretty huge leap in viscosity at temp.

Anyone else have this mess up and turn out ok with thicker stuff back in?




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[PwrWgn]

Nothing wrong with GL4 (manual transmission) fluid in an 01E. It's a synchronized manual gearbox, that is what the GL4 specification is for. Focus on getting the right viscosity, quality (synthetic), and quantity (~6mm below fill hole) of fluid.

As for viscosity, 75W-80 or 75W-90 (factory specification) would both be good options. I have been looking at 75W-85 (Ravenol MTF-1) for the next fill.

[RocksForsSale]

Nothing wrong with GL4 (manual transmission) fluid in an 01E. It's a synchronized manual gearbox, that is what the GL4 specification is for. Focus on getting the right viscosity, quality (synthetic), and quantity (~6mm below fill hole) of fluid.

As for viscosity, 75W-80 or 75W-90 (factory specification) would both be good options. I have been looking at 75W-85 (Ravenol MTF-1) for the next fill.

This viscosity is way off at the straight 75w. How bad? 6 whatever vs a called for 14…


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[PwrWgn]

Sorry I should have tried to answer your original question: I'm sure no harm done by driving it around with 75W. A thicker oil might give you better performance and/or protection at temp, but might be hard to beat the 75W for cold shifting!

The "G052-911" in that table is pretty much the universal spec for the 01E in Elsa. I believe the units shown at 40C and 100C are Centistokes (cSt).

[ReggieNoble]

Simply put GL4 is safe for brass bits, GL5 not so much.

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[RocksForsSale]

Sorry I should have tried to answer your original question: I'm sure no harm done by driving it around with 75W. A thicker oil might give you better performance and/or protection at temp, but might be hard to beat the 75W for cold shifting!

The "G052-911" in that table is pretty much the universal spec for the 01E in Elsa. I believe the units shown at 40C and 100C are Centistokes (cSt).

I assume no one runs this FE fluid. It’s good to know you don’t think it will hurt anything. What to me is a bearing noise has me a little concerned.

My welded diff didn’t have any. This one is new on a 4:1 ran with this fluid now wu wu wu and wuuuuuuu on decel. It’s not loud loud but wasn’t there with the old setup. Switched to sterns streets. I hope this MT-90 quiets it down, and it’s not glittery when I remove the fluid.


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