Is Syntrax really a GL 4/5 oil??

[nqcairns]

I have just been reading this thread -
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=16;t=002392;p=1

Although after ringing Castrol to double check they said it was a GL-5.

Too scared to use a GL-5 in my box.

What gives?

cheers nqcairns

 

[tdi-rick]

Chris,
if you look on the second page of the PDS, it says,

quote:

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Application
* Manual transaxles, manual transmissions where API GL4 or 5 is recommended,....

---

 

[nqcairns]

Yeah Rick thats what I told the castrol technical adviser and he point bank stated it was not a GL-4 but a GL-5 only becuase that is what his reference material said.
Buggered if I know, he probably doesn't either!!
I might ring again to see what another person says.
cheers.

 

[tdi-rick]

quote:

---

the castrol technical adviser and he point bank stated it was not a GL-4 but a GL-5 only becuase that is what his reference material said.

---

Did you point out to him that it can cover both specs ??
I've found that the blokes on the other end of the phone often don't really know a **** of a lot.
The way I look at it is if it is designed for a synchro box, (which it is) it will be brass/yellow metal compatible.
I doubt very much if they would formulate a PAO/ester oil, then use reactive sulphur in it to up the EP rating.
I don't think too many brews these days still use it.
Doesn't Castrol recommend Syntrax for these boxes anyway ??
I've used it, and it worked well, allthough it wasn't in for a terribly long time (replaced with Redline MT90) After using the Redline, I wouldn't hesitate to use Castrols synthetic gear oils.

Doug Hillary, who sadly doesn't post on BITOG any more, runs a fleet of semis, is an advisor to other fleet operators, and after extensive testing swears by Castrols syntheic gear lubes

 

[nqcairns]

Thanks Rick I think it is all in the wording of that doc, "manual transmissions where API GL-4 or 5 is recommended"

My manual trans has only a GL-4 spec for reasons I dont fully understand - age of the GL-5 spec?.

If my ownwers manual said a GL-4 or a GL-5 I would go with the syntrax GL-5. Hope I made sense I looked a bit deeper into it today.

If I was keeping this car for only 5 years or so I would just do it and see what happens but it is in such great condition esp the drivetrain I will see how far it can go before it falls apart or 800-1m k on the diesel whichever comes first.

cheers nqcairns