Anyone know what it matters, GL4 vs. GL5? MT1? Not much in the way of GL4 out there, it's all GL5. What gets hurt if you put the GL5 in a maual transmission spec'd for GL4?
GL4, GL5, MT1
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There are a LOT of posts about this. Maybe it is hard to specifically search for, though.
Old GL5 could be corrorive to yellow metals [synchros]. It would take a lot of heat and some moisture, though.
Gl4 had about 1/3 the sulfer based corosive properties.
Modern GL5s are buffered, and usually are spec'd as GL4-GL5.
So, the bottom line is, there probably won't be any extra wear/corrosion with a modern GL5 [listed as GL4-GL5], but shifting may not be the greatest, as the friction modification is slippery for synchros.
Ask Specialty Formulations for a good sauce for your tranny. They have superb fluids.
Old GL5 could be corrorive to yellow metals [synchros]. It would take a lot of heat and some moisture, though.
Gl4 had about 1/3 the sulfer based corosive properties.
Modern GL5s are buffered, and usually are spec'd as GL4-GL5.
So, the bottom line is, there probably won't be any extra wear/corrosion with a modern GL5 [listed as GL4-GL5], but shifting may not be the greatest, as the friction modification is slippery for synchros.
Ask Specialty Formulations for a good sauce for your tranny. They have superb fluids.
Actually, our resident SF guy did give me a link to a nice lube, but it's 30.00 a gallon, a gallon is the least you can purchase, and my tranny needs a whopping 2.2 quarts. I don't mind having an extra few ounces around, but nearly 2 quarts sitting around forever? Nah.
One of the threads mentioned a make of car that has brass/bronze synchros that actually specs GL-5 M-1 Synthetic. Might try that. I'm a big M-1 fan..
Thanks, Mech!
One of the threads mentioned a make of car that has brass/bronze synchros that actually specs GL-5 M-1 Synthetic. Might try that. I'm a big M-1 fan..
Thanks, Mech!
I had a 97 Prizm (Corolla) that had a GL4 75w90 spec. I tried Amsoil GL4, Mobil 1 GL5, ST Synth Gear Oil, and all of them caused shifting problems. There was a post here about a gent who used some dino GL4/GL5 and added some Pennzoil Synchromesh. I tried it and it worked great for me as well. The problem as I understand it is not only the potential for corrosive properties in the GL5 fluids, but also that most of them are designed for multiuse in limited slip differentials and that causes some problems with the synchros in certain transmissions.
Anyway, I really liked the GL4/GL5 and Synchromesh mix, and the tranny shifted great. The Prizm only used 2.6 quarts, so I feel ya on spending the cash for a gallon. The whole change for the dino and Synchromesh was about $12. If that is not your cup of tea, Amsoil makes a nice GL4 spec MT Synth lube (didn't work for me, but I'm sure it's a good fluid), that is about $6 a quart.
The original thread is
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=16;t=002665
Yeah, shoulda mentioned the make. 2005 Hyundai Accent GT 5-speed. Kicker is, I called the Stealer today (May8), and what do you suppose the Stealer's Service Manager advised, and recommended highly?
No kidding! Mobil 1 GL-5 Synthetic 75W-90. Says they spec it, install it (charge extra for it for the boutique oil demanders, I guess?) and carry it on the shelf. He claims they haven't had a GL-4 tranny-lube in there for two or three years..
Is he fulla poo, or what? It gets weirder and weirder, the contradictions between owners manual and Hyundai's Stealer Service Reps, at least in Fairfax Va..
I'd be all over the GL4 75W90 Amsoil if I could only FIND it. It's the same cost as the Mobil1 GL5, and Stealer Rep notwithstanding, I gotta figure the factory knows better than the Stealer..Are ALL the Stealers this much at variance with the factory, or is it just Hyundai?
Jeeps, I'll check up on the synchomesh, but the product docs from Pennzoil are all from the year 2000. Who knows if they still make it, even?
Thanks all!.
No kidding! Mobil 1 GL-5 Synthetic 75W-90. Says they spec it, install it (charge extra for it for the boutique oil demanders, I guess?) and carry it on the shelf. He claims they haven't had a GL-4 tranny-lube in there for two or three years..
Is he fulla poo, or what? It gets weirder and weirder, the contradictions between owners manual and Hyundai's Stealer Service Reps, at least in Fairfax Va..
I'd be all over the GL4 75W90 Amsoil if I could only FIND it. It's the same cost as the Mobil1 GL5, and Stealer Rep notwithstanding, I gotta figure the factory knows better than the Stealer..Are ALL the Stealers this much at variance with the factory, or is it just Hyundai?
Jeeps, I'll check up on the synchomesh, but the product docs from Pennzoil are all from the year 2000. Who knows if they still make it, even?
Thanks all!.
Crazy
I am in a similar position. I have a Hyundai Getz 1.3 manual which specifies 75W-90 GL-4 but this spec is hard to find in Australia. I have e-mailed Hyundai to see if they will allow Redline (what a price!!!!!) which is a full synthetic 75W-90 GL-4 and the only synth I can find. I wonder if GL-5 oils produced now do not have a detrimental effect on brass/phosphor-bronze components in synchro gearboxes.
Roger
I am in a similar position. I have a Hyundai Getz 1.3 manual which specifies 75W-90 GL-4 but this spec is hard to find in Australia. I have e-mailed Hyundai to see if they will allow Redline (what a price!!!!!) which is a full synthetic 75W-90 GL-4 and the only synth I can find. I wonder if GL-5 oils produced now do not have a detrimental effect on brass/phosphor-bronze components in synchro gearboxes.
Roger
Update
Just got a reply from Hyundai re above query
" Contact your nearest dealer who will be able to assist you " So no further forward as I would not expect a dealer to answer my query.
Roger
Just got a reply from Hyundai re above query
" Contact your nearest dealer who will be able to assist you " So no further forward as I would not expect a dealer to answer my query.
Roger
I can't imagine what a GL5 would have in them that would wreck/corrode sintered-metal synchros, I would think each iteration of a lube would be backward-compatible, but apparently it ain't so.
We did this tap dance awhile back, RayH has a Hyundai or two or three in his stable, but I dunno if they're manual trannys or not. I found a bunch of Acura/Civic forums, amongst others, where the members had crummy luck with all the synthetic lubes with 5-speed trannys. Not that they flew apart or anything, just that they couldn't shift them while moving without things grinding or having to double-clutch a lot.
They did have many replies regarding the Synchromesh and dino mix, I believe I'll find that and give it a try. I don't go around downshifting while in motion much, certainly not in order to slow down. I always thought downshifting was to go faster/keep from lugging, but I suppose if these boys thrash their vehicles, high-rev downshifting is a natural part of life on the road. This is a stupid Hyundai, fer corn's sake, I don't know how it could be so sensitive, nor the Stealer's service manager SO at odds with the factory.
Thanks for the tips, Jeeps and everyone! Good luck, Roger, if I were you, I'd be looking for the SynchroMesh. The price of admission seems about right.
We did this tap dance awhile back, RayH has a Hyundai or two or three in his stable, but I dunno if they're manual trannys or not. I found a bunch of Acura/Civic forums, amongst others, where the members had crummy luck with all the synthetic lubes with 5-speed trannys. Not that they flew apart or anything, just that they couldn't shift them while moving without things grinding or having to double-clutch a lot.
They did have many replies regarding the Synchromesh and dino mix, I believe I'll find that and give it a try. I don't go around downshifting while in motion much, certainly not in order to slow down. I always thought downshifting was to go faster/keep from lugging, but I suppose if these boys thrash their vehicles, high-rev downshifting is a natural part of life on the road. This is a stupid Hyundai, fer corn's sake, I don't know how it could be so sensitive, nor the Stealer's service manager SO at odds with the factory.
Thanks for the tips, Jeeps and everyone! Good luck, Roger, if I were you, I'd be looking for the SynchroMesh. The price of admission seems about right.
MolaKule
Staff member
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What matters is, what is the specified fluid's viscosity, and then try to find a MTL specific 75W85 fluid for your tranny.
The Pennzoil Synchromesh fluid has a viscosity of 9.0 cSt and the 75W90 diffy fluid is approx. 16.5 cSt, so a 50/50 mix is about 12.9 cSt, which is still a bit thick for most Honda transmissions.
Evem MTG is still too thick for this application.
I think our MTL-P would be more suitable.
From what I understand MT-1 is from synchro-less (semi-)truck trannies. GL-5 is for rear diffs or anything with hyploid (90 degree) gears. And GL-4 is for regular trannies and transaxles.
Some gear oils will say GL4/GL5, you can use these in a manual tranny.
M1 says right on the bottle that it's a MT-1 and GL-5 rated. It's not for car trannies... Too much EP (Extreme Pressure) additives make for bad shifting. "Too slick for the synchros" is the term I've hear.
Redline 75W90 is more of a GL-5. While their MT-90 75W90NS, and 75W140NS are more of a GL-4.
Poyal Purple and RL have always worked well for me in Mazda (FWD, RWD, and AWD) or Datsun/Nissan (RWD) trannies.
P.S.
If you're really feeling ballsy you could try some engine oil in your tranny. Look for one that's low in Moly and it should shift better. Honduh rec'd a 10W30 but I'd use a 15W40 or 20W50. Delvac or Delo would be good choices.
Some gear oils will say GL4/GL5, you can use these in a manual tranny.
M1 says right on the bottle that it's a MT-1 and GL-5 rated. It's not for car trannies... Too much EP (Extreme Pressure) additives make for bad shifting. "Too slick for the synchros" is the term I've hear.
Redline 75W90 is more of a GL-5. While their MT-90 75W90NS, and 75W140NS are more of a GL-4.
Poyal Purple and RL have always worked well for me in Mazda (FWD, RWD, and AWD) or Datsun/Nissan (RWD) trannies.
P.S.
If you're really feeling ballsy you could try some engine oil in your tranny. Look for one that's low in Moly and it should shift better. Honduh rec'd a 10W30 but I'd use a 15W40 or 20W50. Delvac or Delo would be good choices.
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