GL5 vs. GL4 Gear Oil for Transmission
11-18-2008, 12:01 PM
#28
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hey guys i have a few dumb questions :'-(
im reading that chart with the viscosity b4 and after the testing and looking how bad royal purple did, there is now doubt in my mind thats why my tranny has been messing up so bad. I am going to be switching over to somethin else. What id like to know is why RP seems to be popular when the tests show it has a signifigant reduction after testing, is it the brand name that made it a popular choice?
ill admit i only put it in because i hear of word of mouth how good their products are. The initial viscosity in the chart is very good...is this the type of fluid you use for short term useasge, sort of like using it for a track day or two then swapping out? I used it on a street driven car for a little over a year and i admit for the 1st 2 months my shifts were incredible...precise and effortless. Now shifting is a real chore.
A side question, i saw seafoam has a tranny cleaner, since ive been using this RP stuff, id like it all gone, is the tranny cleaner ok to use in our tranny to do a flush and start off with fresh fluid? I want to make sure i give the tranny a fresh start...there may still be hope i can salvage this tranny :-)
As for the diff ive been using Mobil 1, how can i tell if there is something wrong with it...as far asd i kno ive had no problems in the dif lol...sorry if this Q was a thread HJ
im reading that chart with the viscosity b4 and after the testing and looking how bad royal purple did, there is now doubt in my mind thats why my tranny has been messing up so bad. I am going to be switching over to somethin else. What id like to know is why RP seems to be popular when the tests show it has a signifigant reduction after testing, is it the brand name that made it a popular choice?
ill admit i only put it in because i hear of word of mouth how good their products are. The initial viscosity in the chart is very good...is this the type of fluid you use for short term useasge, sort of like using it for a track day or two then swapping out? I used it on a street driven car for a little over a year and i admit for the 1st 2 months my shifts were incredible...precise and effortless. Now shifting is a real chore.
A side question, i saw seafoam has a tranny cleaner, since ive been using this RP stuff, id like it all gone, is the tranny cleaner ok to use in our tranny to do a flush and start off with fresh fluid? I want to make sure i give the tranny a fresh start...there may still be hope i can salvage this tranny :-)
As for the diff ive been using Mobil 1, how can i tell if there is something wrong with it...as far asd i kno ive had no problems in the dif lol...sorry if this Q was a thread HJ
11-18-2008, 01:03 PM
#29
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API GL-4 and API GL-5 products typically use the same extreme pressure (EP) additive system, with the API GL-5 having about twice the concentration of a API GL-4. In service, these additives become active under extreme load and temperature when the protective oil film can be squeezed away. EP additives work by forming wear-resistant compounds with the metal of the gear tooth surface. As the gears mesh, these compounds shield the gear teeth from direct metal-to-metal contact that would cause wear and damage to the gears. If too little of the active additive is present, proper protection would be compromised. Too much of this additive could cause excessive chemical corrosion of the gear surface. If an API GL-5 gear oil is used in a application where API GL-4 gear oil is called for, chemical corrosion of "yellow metal" components may occur, such as bronze synchronizers, brass bushings, etc. This may lead to shifting difficulties or shortened equipment life.
I use GL4 to play it safe, but I still don't quite understand the real-world application.
GL-5 sounds like it would be better, except it eats yellow metal (synchro rings).
So, are there transmissions out there that *don't* use yellow metal? How common is that? And why would a Mfr list both fluids as an option for a tranny which does use brass alloys?
11-21-2008, 06:07 PM
#31
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I dont know the mazda trans at all but in any trans with any brass parts like syncros it is a big no-no to use GL5, it contains additives that eat away at brass. GL4 for me and hopefully a non sulfer based fluid after reading the horror stories of trans oil stinking in the cabin right after the fluid is changed, with no real resolutions to the problem that i read
i have one word: SYNCHROMESH
it will most likely be blended with valvoline durablend(synthetic blend) and even then, i'm hesitant. it'll most likely be reserved for the diff... maybe blended with valvoline high performance regular fill.
--input needed--
11-21-2008, 06:21 PM
#32
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Next time I change my gear oil, which should be in a few months, I'll try a Motorcraft synthetic blend that the Miata guys say is very helpful in curing any grinds and is supposedly specifically formulated for NB 6 speeds of which the 2004-2008 RX-8 transmission is a variation of. I'll check back when I do.
and i've also heard of synchromesh being used.... and also popular in the honda crowd.
on a side note, have you checked walmart for your motorcraft fluids? you might want to check that out... i might have seen that there and wanted to try it out.
but if you go ahead and try it out first, let me know of your immediate results.
wait, i might see you 2morrow at the meet. more details to come.
11-21-2008, 09:02 PM
#35
It took quite a few miles and lots of track sessions to realize my issues with GL5 in the trans. All of a sudden I didn't have 4th gear on the track @ ~90mph. Not once, but all weekend. Made probably 70+ tries for 4th gear.
Swapping out to a GL4 resolved the issue without a rebuild. No grinding or any issues after the swap. Was running/shifting fine the last time the car was run.
11-21-2008, 09:06 PM
#36
Transmission:
http://www.amsoil.com/storefront/mtf.aspx
Differential:
street:
http://www.amsoil.com/storefront/svg.aspx
track:
http://www.amsoil.com/storefront/svt.aspx
GEAR OIL IS CHEAP! CHANGE YEARLY!
Last edited by mac11; 11-21-2008 at 09:10 PM.
11-22-2008, 01:36 AM
#37
Just bought some of the Motorcraft manual transmission oil.
http://www.fcsdchemicalsandlubricant...ission%20Fluid
It's a full synthetic GL-4, supposedly German made.
Hope it is as good as the Miata/Focus guys say it is.
Probably install it this weekend.
http://www.fcsdchemicalsandlubricant...ission%20Fluid
It's a full synthetic GL-4, supposedly German made.
Hope it is as good as the Miata/Focus guys say it is.
Probably install it this weekend.
11-22-2008, 01:39 AM
#38
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Next time I change my gear oil, which should be in a few months, I'll try a Motorcraft synthetic blend that the Miata guys say is very helpful in curing any grinds and is supposedly specifically formulated for NB 6 speeds of which the 2004-2008 RX-8 transmission is a variation of. I'll check back when I do.
11-22-2008, 01:53 PM
#40
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We should remember that years ago, when everyone was on the Royal Purple versus Redline hype, many people chose Royal Purple for their transmission because those idiots at Royal Purple told us it would work great. I remember calling them myself and getting the same encouragement.
Luckily, I decided to go with Redline for my trans and Royal Purple for my differential.
Can Royal Purple be sued for this?
Luckily, I decided to go with Redline for my trans and Royal Purple for my differential.
Can Royal Purple be sued for this?
11-22-2008, 04:55 PM
#42
Ray you know as well as I do how much bad advice is there out there on the 'net. I can't believe people are still willing to just take some guy's word for it. Mine, yours or otherwise. Especially when said guy has a financial interest in selling that product, like a sales rep from Royal Purple that you get on the phone. Like the lubricants I just recommended in this very thread. I have used them, I like them but what does someone across the world know about who I am? I haven't run any scientific studies on any of that stuff. I put it in my car. That is all.
People need to take responsibility for their actions. There is a lot of money at stake when you are talking about a motor vehicle. Why rely on someone else when they are not going to pay for your car if it breaks? Some vendors may have a conscience but that doesn’t mean they have the knowledge. And if they are turning a profit off of their recommendations their motivations should always be scrutinized.
People need to take responsibility for their actions. There is a lot of money at stake when you are talking about a motor vehicle. Why rely on someone else when they are not going to pay for your car if it breaks? Some vendors may have a conscience but that doesn’t mean they have the knowledge. And if they are turning a profit off of their recommendations their motivations should always be scrutinized.
Last edited by mac11; 11-22-2008 at 04:57 PM.
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11-23-2008, 02:53 PM
#47
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Put in the Motorcraft last night and ended up putting about 250 miles on the car last night. There's a distinct improvement in smoothness when the transmission is warmed up. It now slides from gear to gear effortlessly. The tranny also seems to reach operating temperature quicker. The 1-2 shift when cold still requires a delicate touch. It feels like the Motorcraft isn't as "clingy" as the Redline because even if the tranny is hot, when you let the car sit for a little bit of time, the first couple shifts after you start driving again is a little more notchy.
The miata.net guys report this oil requires some miles to break in, so I'm hoping it'll get even better in the coming days.
The miata.net guys report this oil requires some miles to break in, so I'm hoping it'll get even better in the coming days.
11-23-2008, 09:41 PM
#50
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I have been explaining all this as have TeamRX8 and JaxRX8, as well, although our opinions may vary. I first discussed the problems with RP 4 years ago and it had nothing to do with the rating.
The point is, I am glad people are starting to "get" it. Now I wanna see what the Eneos GL-5, 75W90 will do to my trans in the long-term.........
The point is, I am glad people are starting to "get" it. Now I wanna see what the Eneos GL-5, 75W90 will do to my trans in the long-term.........