O.K. to use GL-5 in Manual Transmission........

[Flimflam]

It's been many years since I last changed Manual Transmission gear oil. My current 4 1/2 year old car has only 41,000 miles on it, so I have never done a gear oil change on it. My question: my Owner's Manual calls for GL-4 80w-90 in the Manual Transmission. But all the Popular gear oils these days seem to be GL-5. So, is it O.K. for me to pour GL-5 into my purportedly GL-4 gearbox? I am worried to run into "unexpected" happenings such as not being able to get into the next gear.

 

[moribundman]

Check the Red Line site and see what they say about the use of GL4 and GL5 gear oils.

 

[TooSlick]

Flimflam,

It is best to consult the oil manufacturer to see if their additive chemistry is compatable in a GL-4 application. The Amsoil gl-4/gl-5 stuff works fine here and I believe the Valvoline gear lube does also. I'd check on other brands ...

Of course the Redline MT-90 would be excellent as well ....

TS

 

[sbc350gearhead]

Royal Purple's max-gear fluid is GL-4 and 5 approved. I use it in my BW super T-10 (calls for gl-4 80w) and have never had a problem.

 

[Flimflam]

quote:

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Originally posted by Flimflam:
It's been many years since I last changed Manual Transmission gear oil. My current 4 1/2 year old car has only 41,000 miles on it, so I have never done a gear oil change on it. My question: my Owner's Manual calls for GL-4 80w-90 in the Manual Transmission. But all the Popular gear oils these days seem to be GL-5. So, is it O.K. for me to pour GL-5 into my purportedly GL-4 gearbox? I am worried to run into "unexpected" happenings such as not being able to get into the next gear.

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Fellers, thank you for the good advice......

I have decided to do exactly what my owner's manual tells me. GL-4 in the gearbox and GL-5 in the rear differential.

The gearbox will get Red Line MT-90 gear oil. The rear differential will get Schaeffer 267 GL-5 gear oil.

I figure that if I do it exactly the way the Manufacturer tells me to, I am covered in case my synchro's get eaten up and/or corroded.