Gear Oil GL-4 or 5, syncromesh and all that nonsense

[edk]

Here's what I've been reading on another forum.

Honestly I wouldn't use it. It's not API certified...that in itself isn't really a reason to use it. It's just that because of that, you can't tell whether it's GL-4 or GL-5...they say it can be used for either spec. But GL-5 causes damage to Nissan transmissions so yeah.

Really . How does the GL-5 damage the tranny.

In theory GL-5 has more sulfur used in anti-wear compounds. These can attack the bronze synchronizers. Modern GL-5's should not do this but there are no guaranteers.

another reason to not use GL-5's designed for differential gear use is that Manual transmission synchros require a certain amount of friction to shift smoothly. without this, you'll get gear clash. This is according to redline's MT-90, which has the correct amount of friction for the synchros...i suppose. but yea, the sulfur thing is the big one here. use a GL-4 Manual Transmission Lube

I have an Amsoil oil that's not API rated but is called 'Manual Synchromesh Transmission Fluid'. On what you're saying will that mean this oil is fit for the job still? It's not in the tranny yet so could switch to a GL-4 if not.

http://www.opieoils.co.uk/p-1051-amsoil-synthetic-manual-transmission-fluid-mtf.aspx

Basically the oil I have doesnt specifically say it's GL-4 but it does say it's for manual syncromesh. Is it going to attack the bronze in nissan boxes?
Any thoughts from the great AOC?

 

[Sam]

mt90 ftw

 

[edk]

Ok. I've already bought the oil I linked to, but would like to know if it's any good or not please.

 

[rowdy-GTi]

If you`re worried about your tranny use redline MT-90 / Shockproof. This is what i use. Expensive, but good reassurance.

 

[edk]

Well it's actually about the same price as the Amsoil stuff I bought. Thanks for the recommendations but a yay or nay for the oil I already have would be cool . If it turns out to not be good then I'll get the MT90 as you guys say.

 

[oilman]

The Amsoil you have purchased is fine, its a GL4 75w-80 and a very good one. We sell a lot of it to the Honda chaps.

Cheers

Guy

 

[edk]

Thanks for the reply Guy .