Recent Topics
Consensus on Top 5 reasonably available filters
by circle1m
07/31/14 02:33 PM
Motul 8100 Eco-nergy 5W30
by circle1m
07/31/14 02:27 PM
2001 Impreza OBS, M1 5W30, 5k on oil, 159k on car
by kaesees
07/31/14 02:19 PM
Rear Wheel Bearing Advice Wanted
by Sluggo0018
07/31/14 02:10 PM
Wix vs Dealership OEM Oil Filters
by SwedishRider
07/31/14 02:10 PM
What failed in this headlight?
by spavel6
07/31/14 01:34 PM
Tribology of a Driveline Material
by MolaKule
07/31/14 01:14 PM
Euro Pennzoil Platinum w/ PurePlus - 0W-40, 5W-30
by vinu_neuro
07/31/14 01:03 PM
2011 Acadia 3,6L DI ACDelco Dexos 5W-30
by rbarrios
07/31/14 01:03 PM
Do PureOne Filters have an Anti-Drain Back Valve??
by AdmiralYoda
07/31/14 12:55 PM
Price check on vintage mopar
by pacem
07/31/14 12:35 PM
DONE with Rockauto
by jrustles
07/31/14 12:04 PM
Newest Members
kaesees, bprat318, Winter_Texan, SloopJohnB, world123
50815 Registered Users
Who's Online
117 registered (AdmiralYoda, 05LGTLtd, 2009Edge, 2KBMW, aquariuscsm, 9 invisible), 1981 Guests and 229 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
50815 Members
64 Forums
217105 Topics
3418478 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG

Page 1 of 3 1 2 3 >
Topic Options
#1157073 - 05/22/08 10:50 PM Question about GL4 vs GL5 gear oils.
aquariuscsm Online   content


Registered: 12/30/06
Posts: 9418
Loc: South Texas,USA
There`s something I`ve been wondering about concerning these two classifications of gear oils. GL4 is basically a "toned down" version of GL5 per se from what I understand (lower levels of certain additives),or am I uneducated about the chemistry of the two?

Reason I ask,is that if GL4 gear oils are "old technology" (I read that on some car forum somewhere,can`t remember where) and today`s GL5 oils are way more advanced than yesterday`s,would a GL5 (or at least one that`s rated GL5 and MT1) oil be better in a manual tranny because of better gear shock/load protection via extreme pressure additives? I keep hearing/reading about people using GL5 gear oils for years in their manual trannies with no issues at all. If a manual tranny has no ill effects (no brass syncho issue) would a GL5 oil be a better choice for gear protection?

If this makes no sense,I apologize in advance :^) I`m just trying to learn all I can.
_________________________
1996 Nissan 300ZX 5-speed,Arctic Pearl(#175 of 300)
Syntec 10W40/Fram Ultra
Amsoil MTG(tranny)
Amsoil 80W90 GL5(rear diff)
Mobil 1 ATF
Redline Water Wetter

Top
#1157077 - 05/22/08 10:56 PM Re: Question about GL4 vs GL5 gear oils. [Re: aquariuscsm]
ewetho Offline


Registered: 05/05/06
Posts: 1304
Loc: Kankakee, IL
Would use GL-4 in any trans that specs it. Never in a separate diff but in a trans.

They are different animals when tranmissions are concerned.
_________________________
2004 Neon SE 2.0L Current Fill
Motorcraft 5W-30, Motorcraft FL-300

Top
#1157086 - 05/22/08 11:19 PM Re: Question about GL4 vs GL5 gear oils. [Re: ewetho]
rationull Offline


Registered: 04/28/07
Posts: 2653
Loc: California, USA
Not sure if this applies to the Z32 but I used to have a 280zx with MT. I remember reading that GL-5 gear oil would eat up the brass synchros so only GL-4 was acceptable. Don't know if it's true but IIRC I read it on the zcar.com forums and those guys are generally quite knowledgeable (at least on the S30/S130 forum, not sure about the others).

Top
#1157088 - 05/22/08 11:23 PM Re: Question about GL4 vs GL5 gear oils. [Re: rationull]
rationull Offline


Registered: 04/28/07
Posts: 2653
Loc: California, USA
Oh and another note: good luck finding GL-4 in the chain auto parts stores. Around here only Napa had it, and the guys at the other stores didn't really know what it was or told me that GL-5 would be fine. Oh well, I like Napa better anyway.

Top
#1157089 - 05/22/08 11:23 PM Re: Question about GL4 vs GL5 gear oils. [Re: rationull]
aquariuscsm Online   content


Registered: 12/30/06
Posts: 9418
Loc: South Texas,USA
 Originally Posted By: rationull
Not sure if this applies to the Z32 but I used to have a 280zx with MT. I remember reading that GL-5 gear oil would eat up the brass synchros so only GL-4 was acceptable. Don't know if it's true but IIRC I read it on the zcar.com forums and those guys are generally quite knowledgeable (at least on the S30/S130 forum, not sure about the others).


What really got my curiosity going is that a guy on Twinturbo.net copied and pasted a Nissan TSB that said GL4 and GL5 gear oils are acceptable in the Z32 manual transmission and all other Nissan manual transmissions. Service manager at the Nissan dealer here said the same thing as well.
_________________________
1996 Nissan 300ZX 5-speed,Arctic Pearl(#175 of 300)
Syntec 10W40/Fram Ultra
Amsoil MTG(tranny)
Amsoil 80W90 GL5(rear diff)
Mobil 1 ATF
Redline Water Wetter

Top
#1157090 - 05/22/08 11:28 PM Re: Question about GL4 vs GL5 gear oils. [Re: aquariuscsm]
aquariuscsm Online   content


Registered: 12/30/06
Posts: 9418
Loc: South Texas,USA
Here`s a copy and paste of the post on tt.net:

TSB NTB 94-100 is titled "RECOMMENDED FLUIDS, LURICANTS AND CHEMICALS FOR NISSAN VEHICLES". For manual transmissions it specifies a GL-4 or a GL-5, 80W90(RWD), 75W90(FWD), mineral or synthetic. It further shows as a recommended aftermarket product Castrol Hypoid "C" or equivalent; Castrol Synthetic Gear Oil 75W90 P/N 00672 or Equivalent
_________________________
1996 Nissan 300ZX 5-speed,Arctic Pearl(#175 of 300)
Syntec 10W40/Fram Ultra
Amsoil MTG(tranny)
Amsoil 80W90 GL5(rear diff)
Mobil 1 ATF
Redline Water Wetter

Top
#1157091 - 05/22/08 11:29 PM Re: Question about GL4 vs GL5 gear oils. [Re: aquariuscsm]
rationull Offline


Registered: 04/28/07
Posts: 2653
Loc: California, USA
Huh. Any idea how far back that TSB goes? Like I said the advice I got was directed toward transmissions 13-26 years older than yours so it's possible it didn't apply after the S130. I'm also not sure whether it ever applied to the BorgWarner trannys that came in the turbo cars.

Or, it's possible that the stuff I read was only true for older GL-5 oils.

Top
#1157098 - 05/22/08 11:43 PM Re: Question about GL4 vs GL5 gear oils. [Re: rationull]
aquariuscsm Online   content


Registered: 12/30/06
Posts: 9418
Loc: South Texas,USA
Here`s a link where there`s some discussion about GL4/GL5-MT1 gear oils:

http://64.233.167.104/search?q=cache:8E-...clnk&cd=5&gl=us
_________________________
1996 Nissan 300ZX 5-speed,Arctic Pearl(#175 of 300)
Syntec 10W40/Fram Ultra
Amsoil MTG(tranny)
Amsoil 80W90 GL5(rear diff)
Mobil 1 ATF
Redline Water Wetter

Top
#1157136 - 05/23/08 01:11 AM Re: Question about GL4 vs GL5 gear oils. [Re: aquariuscsm]
rationull Offline


Registered: 04/28/07
Posts: 2653
Loc: California, USA
Very interesting. Honestly it seems most likely to me that the GL-5 is probably fine. Saying it will wear out your synchros feels kind of like saying YB Pennzoil will turn to wax :) When I was trying to decide what gear oil to get for my Z I had yet to discover BITOG and was changing my oil every 3000 miles. But I digress.

The fact that GL-5 is recommended in the diff instead of GL-4 may imply that the GL-5 is actually better if there are no materials issue. Or maybe not.

I think I'd still go for what's manufacturer recommended if it's available (especially if you can find something good like Redline MT90 which is GL-4 rated) but I wouldn't be surprised if the real truth is GL-5 is fine and it doesn't really matter.

Top
#1157247 - 05/23/08 09:15 AM Re: Question about GL4 vs GL5 gear oils. [Re: rationull]
gtx510 Offline


Registered: 04/26/04
Posts: 1463
Loc: CA
I bet it says GL-4 or GL-5 because GL-4's are tough to find in the US.
I think all GL-5's are now MT-1 rated and should not eat yellow metals.

http://www.lubrizol.com/products/automotive-gear-oil/GL5.asp

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729255
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729289

Top
#1157269 - 05/23/08 09:54 AM Re: Question about GL4 vs GL5 gear oils. [Re: gtx510]
MolaKule Offline


Registered: 06/05/02
Posts: 14134
Loc: Midwest
_________________________
I told a chemistry joke....there was no reaction. smile

Top
#1157337 - 05/23/08 11:16 AM Re: Question about GL4 vs GL5 gear oils. [Re: gtx510]
aquariuscsm Online   content


Registered: 12/30/06
Posts: 9418
Loc: South Texas,USA
 Originally Posted By: gtx510
I bet it says GL-4 or GL-5 because GL-4's are tough to find in the US.
I think all GL-5's are now MT-1 rated and should not eat yellow metals.

http://www.lubrizol.com/products/automotive-gear-oil/GL5.asp

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729255
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729289


VERY good link. That completely explained all the different classifications where the complete and total layman (me) could understand it. Thanks gtx510!
_________________________
1996 Nissan 300ZX 5-speed,Arctic Pearl(#175 of 300)
Syntec 10W40/Fram Ultra
Amsoil MTG(tranny)
Amsoil 80W90 GL5(rear diff)
Mobil 1 ATF
Redline Water Wetter

Top
#2124259 - 01/01/11 10:50 PM Re: Question about GL4 vs GL5 gear oils. [Re: aquariuscsm]
Kaie Offline


Registered: 10/31/10
Posts: 259
Loc: Kenmore, WA
Bringing this out of the depths.

After reading this thread and http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729255

I'm still unclear... Here is a quote about GL-4 and GL-5 from that link.

Originally Posted By: MolaKule

GL-4; Specified for hypoid gear service under severe service but without shock loading. This classification is essentially obsolete but is still specified by some manual transmission/transaxle manufacturers. Implies an EP/AW additive package that contains 30% to 50% less S-P additives than the GL-5 service classification. Some Marine Gear Lubes fall into this classification, especially the full Synthetic Marine Gear lubes and specialty blenders MT lubes that use high levels of esters.

GL-5; Specified for hypoid gear service but with shock loads and severe service operation. Usually meets Mil-L-2105D and in most cases, is the multipurpose automotive gear oil. Most 75W90 to 75W140 grades meet the GL-5 classification. This grade has a high level of Extreme-Pressure additives that could be mildly corrosive to nonferrous parts, such as brass, bronze and aluminum parts. Most of the modern GL-5 lubes contain metal deactivators that prevents attacks by the extreme-pressure additives. In addition to EP additives, these lubes contain rust inhibitors, defoamants, friction modifiers, thickeners, and Viscosity Index Improvers.



If an oil claim both GL-4 and GL-5 is it more likely to be safe for a GL-4 application? I find 'GL-5 lubes contain metal deactivators that prevents attacks by the extreme pressure additives' a little sketchy.

For the record i'm looking at Motul Gear300 75w90 for my VW GL-4 tranny.

Top
#2124463 - 01/02/11 08:22 AM Re: Question about GL4 vs GL5 gear oils. [Re: aquariuscsm]
Bluestream Offline


Registered: 09/13/03
Posts: 3850
Loc: Waterloo, ON
Use the GL-4 for tranny. It wont let you down!
_________________________
2000 Cavalier 2.2 A4
2000 VW Beetle 1.8T M5
2000 Ford Explorer 4.0 4X4
1991 BMW 735iL
"A fool and his money are soon parted" - Thomas Tusser

Top
#2124586 - 01/02/11 11:07 AM Re: Question about GL4 vs GL5 gear oils. [Re: aquariuscsm]
flyingtoaster Offline


Registered: 11/25/10
Posts: 60
Loc: Rancho Cucamonga, CA
My big question on this subject is whether I can use the same hand pump for GL-4 and GL-5 when changing my trans and diff fluid, which one I should change first, and whether I should flush the pump with the fluid I'm about to use.
_________________________
2006 Honda S2000
Rotella T6 5w40, OEM Filter
Amsoil MTF
Amsoil 75w140
ATE SL.6

Top
Page 1 of 3 1 2 3 >