Why don't I see GL4 much anymore?

[pgtr]

It may be purely perception on my part but purel GL4 oils don't seem to be popping off the shelves in the major brands through the major retail outlets. Sure I see them sometimes in dino oils, sometimes is less well known brands and sure they're available from the boutique brands.

Two possibilities come mind:
- There's not that much market for it. Perhaps true compared to say automatics in the US but still there's millions of manual trannies running around that spec GL4. But I suppose the bigger turf is fought over automatic trannies and rear axles so that's where the shelf space goes?

- There's potential liability of mis-using GL4 say in a rear end so GL4 is avoided or offered as a GL4/GL5 'Combination' blend. Since the boutique brands market to more discriminating buyers there's probably less potential problem for them.

Thoughts?

Thanks,
-T

 

[TooSlick]

Pgtr,

Most of the newer GL-5 gear lubes also carry the MT-1 rating, so they are fine to use in manual transmission applications calling for a GL-4 product. I've been running the Amsoil synthetic gear lubes, which are GL-4/GL-5 rated, for over twenty years in VW transaxles that call for a GL-4 product. No issues at all with corrosive wear to "yellow" metals ....

It is actually cheaper to make a GL-4 only product, since the levels of EP additives are typically 50% lower than for a GL-5.

TooSlick

 

[Steve_RI]

The manual transmission and gearbox in my 89 Pathfinder (manual tranny) specifies a GL-4. When I tried a GL4-GL5 rated gear oil (forget the brand) the truck began to shift horribly and I immediately switched it out with Redline GL-4. There's definitely some compatibility issues with some of the GL4-GL5 rated oils in those older Nissan transmissions. I know some people run the Amsoil GL4-GL5 rated dtuff without any issues though? It must be some additive that is used that causes the problems?

 

[pgtr]

I've run the same GL4/5 'combo' oils too w/o notable problems.

I will add that in some cases I noticed a slight bit of synchro 'notchiness' with he M1 GL4/5 combo in some cases compared to a GL4 only oil.

My thought goes back to things like shelf space, simplicity, liability issues as possible reasons for the widespread absence of pure GL4s in the mainstream.

 

[SteveD2]

Amsoil make the only synthetic GL-4 gear oil that I'm aware of

Ken

[ October 05, 2002, 08:41 PM: Message edited by: BOBISTHEOILGUY ]

 

[GeorgeCLS]

One of the major reasons for lack of GL-4 is that it is no longer a current specification for a gear oil. i.e. the test equipment for GL-4, the tests are gone.. Thus, one can no longer certify a gear lubricant as GL-4... Sooooo, pretty difficult to list a GL-4 specification when the specification and means to qualify no longer exist.....
George Morrison, STLE CLS

 

[BOBISTHEOILGUY]

Thank you George, I was going to say the same thing but glad you got in there.

 

[pgtr]

Interesting. WHen I saw that I went over the api.org and found the following info:

quote:

---

Although this service designation is still used commercially to describe lubricants, some test equipment used for performance verification is no longer available. Procedures to define this performance are currently being reviewed for adoption by ASTM.

---

...from API.org

I for one think it's an important std since I've always owned manual tranny cars/trucks. I'd like to see a more widespread return of lubricants in this classification or an equivalent classification. While most of my vehicles spec either a GL4 or GL5 for the tranny, my own experience suggests that a pure GL4 provides for a subtle improvement in synchro operation and depending on the tranny it may be better for the materials used. Hopefully if they list GL5 in the book, you should be covered but given a choice I think I'd sleep better w/ a GL4.

There are a number of GL4s on the market. Redline, Amsoil, Purple, Sta-Lube, Pennzoil, Valvoline(?) all come to mind. But as I said before, this stuff is not exactly falling of the shelves at the local retailer. Only a few auto parts stores in my area even carry a pure GL4.

THanks,
-T

 

[widman]

While the testing equipment may have gone away, the problem has not. If you put a GL-4/GL-5 Sulfur/phos product in a Volvo ZF transmission, you will burn up the syncrhonizers. So Volvo has started giving an alternative of ATF or Motor Oil, which in the mountains runs higher temps and higher wear then Delo Gear. The Pathfinder trans is more prone to problems as is the Nissan LS Differential, but they can also go away with Delo. Perhaps some of the better synthetics can also match this performance.