transmission oil

A lot of diffrent opinions. What I use: ****** Napa sae 90w GL1 for rear I use 600w (macs sells) and it's really not 600w that's just name and don't ask me why:) it's like 140w
 
Rear axle GL4 or GL5, transmission GL4 only (because of the synchros). GL1 is for straight cut gears. 600w is like a brand name/type of oil and really tells you nothing about what it really is. I'm not so sure it's a difference of opinion as it is misunderstanding.

600w was originally Mobile 600-W steam cylinder oil and is somewhere in the 140 weight range. It was never authorized for use in Ford V8 cars as far as I have even been able to find out. Some model A guys use it.

You really should not run GL1 in an early Ford V8 transmission, probably can get by with it if it's not driven than much or than hard. Not sure why you would want to use it?

GL1 Straight mineral oil for straight cut gears
GL2 Mild EP for worm gears (obsolete)
GL3 Mild EP for spur & spiral bevel gears (obsolete)
GL4 Med EP for moderate severity hypoid gears & manual transmissions
GL5 High EP for all hypoid axles and some manual transmission
GL6 Extra High EP (obsolete)

GL5 will damage "yellow" metals in transmission (such as brass) and should not be used in early Ford V8 transmissions.

SAE stands for the Society of Automotive Engineers. The SAE classification system is a way of defining how thin or how thick an oil is. This is known as an oil’s viscosity. The classifications are listed here in order of increasing thickness: SAE 75W, SAE 80W, SAE 85W, SAE 90, SAE 140, SAE 250. There really isn't any such thing as 140w, it would be SAE 140.
 

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coolcoupe said:
What type or grade of oil should I put in my transmission and the rear-end?
Any help.
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I hope the responses you get will accurately describe the various 'GL' ratings. Having searched the Internet, I can't find a definitive answer concerning GL5 and its effects on the 'yellow' metals in our transmissions - the pros and cons are all over the place. Many sites say to avoid GL5 while many others say GL5 won't do any harm. I'm sure that over the years my transmissions have been topped off with or filled with GL5 with no consideration on my part because I was unaware of any controversy between the various GL ratings/specs. I can't become too enthused about having to drain all of my transmissions because the GL rating of the oil in them is not correct according to some. I'd rather eat a booger than to do this! Does this dreaded GL5 eat the yellow metals when the transmission is static? How long does it take for GL5 to destroy the yellow metals? I wish I would have never become aware of this controversy given the multitude of different opinions....
 
petehoovie said:
I hope the responses you get will accurately describe the various 'GL' ratings. Having searched the Internet, I can't find a definitive answer concerning GL5 and its effects on the 'yellow' metals in our transmissions - the pros and cons are all over the place. Many sites say to avoid GL5 while many others say GL5 won't do any harm. I'm sure that over the years my transmissions have been topped off with or filled with GL5 with no consideration on my part because I was unaware of any controversy between the various GL ratings/specs. I can't become too enthused about having to drain all of my transmissions because the GL rating of the oil in them is not correct according to some. I'd rather eat a booger than to do this! Does this dreaded GL5 eat the yellow metals when the transmission is static? How long does it take for GL5 to destroy the yellow metals? I wish I would have never become aware of this controversy given the multitude of different opinions....
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The Extreme Pressure (EP) additives in GL5 (and to a less extent in GL4) adhere to brass and other "yellow" metals and it them pulls off the surface of the metal. This is a slow process and does not happen over night. Brass will tolerate small amounts of EP and at higher levels it will damage them.

The confusion about this is probably based on the change over time in the different gear lube products. When GL4 and then GL5 first came out it was fairly cut and dry. Several modern GL5 products claim they have changed there formulation to be compatible with "yellow" metal, but there is disagreement on this point among users. You also have to watch out for GL5 being marked as compatible with GL4 and an approved replacement. This is true from a lubrication point of view, but it is not true from a "yellow" metal point of view. So, there is confusion. Myself, I would use GL4 and forget about all the GL5 confusion. I run a WC T5 which requires automatic transmission fluid, more confusion for some!
 
adileo said:
http://www.fordbarn.com/forum/showthread.php?t=170200&highlight=Gl1+gear+oil
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I would consider VanPelt and expert on Ford V8 transmissions (post #21 in the above reference):

"Our lessons from an oil industry engineer......up to GL4 is good, although the GL1 has zero additives and generally only recommended for straight cut gearsets (no synchros). So what you can find these days is the plain GL1 and GL4......both ok on yellow metals. If you choose a GL5 oil, check with the refiner to confirm that it is ok with yellow metal. Some are and some aren't. This is why we only stock the GL4."

__________________
VANPELT SALES LLC
Cincinnati, Ohio
800-299-7496 (in USA)
www.vanpeltsales.com
www.classictransmission.com

You can believe what you want to believe, but think you will find that most folks that understand transmissions and gear lube recommend GL4.
 
I've been using CRC's 'Sta-Lube 85-140 API GL5 Plus' in all of my transmissions. This thread prompted me to contact CRC's Technical Services Dept. via email. I asked them if their product that I'm using is safe to use given the 'yellow' metals in my transmission. Their response was: "All of our gear oils are yellow metal safe. Should you have any other questions please ask. Thank you for choosing CRC products. Have a great day!"
 
StaLube comes highly recommend by a lot of people and they also make a GL4. As for me, I would still prefer the GL4 because GL5 is not required in these transmissions. But that just becomes personal preference.
 
I use a GL4 (80-90) from NAPA in the transmission (4 speed), Overdrive adapter, Overdrive and Rear Axle. That way I don't have to remember much. No problems yet.
Some people use a 50 Weight engine oil in the Overdrives (GV type/Laycock design) and
claim good results.
JSeery,
have you ever heard of any time frame for damage to Yellow synchos?
So much discussion on this subject, but no definitive answers.
Jim
 
It can occure fairly quickly, the problem is it would depend on which specific product you are using. There are detailed articles on the type of damage and how it occurs if you are interested in the chemistry.
 
coolcoupe said:
Anyone know a supplier in Canada for the gl4 ?
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Where abouts are you? After some discussion with the guys here on this site and a lot of great information I started digging a little deeper and I found a guy that can get RedLine products. As a matter of fact, I just picked up two Quarts of MT-90 Which is a 75W-90 GL-4 Gear oil good for transmissions with Synchronized gears (2nd and 3rd) safe for any "Yellow Metals". The product won't tear into the bushings, and as JSeery mentioned it may not take a lot of miles to start to notice problems if you use the wrong product.
I also picked up two quarts of 75w-90 GL-5 gear oil for my differential, made for Hypoid rearends. Red Line as well. A bit pricey, but hopefully it's worth it. I picked it up in Sudbury at a speed shop. I'm sure you could find a shop like that in your area as well.
 
Hi Pogobill, I'm in Midland. Thanks for the info, there is a speed shop in Barrie I'll try. I never thought of them. thanks again and I'll post my findings in case someone else in the area needs some. Moe
 
I pick up a guart of 75-90 gl-4 gone it home and noticed it was sythenic oil !!
Will this be ok to put in my 47 ****** or should it be the normal stuff ?
Thanks for now, Moe
 
Well now you will get mixed reviews. The synthetic should be fine but I believe it can sift a little different that the normal oil and I also believe it has a tendency to be more likely to leak. Depending on how much it cost and how big a hassle it is to take it back you might want to give it a try. It is not going to damage anything.
 
Kahuna said:
I use a GL4 (80-90) from NAPA in the transmission (4 speed), Overdrive adapter, Overdrive and Rear Axle. That way I don't have to remember much. No problems yet.
Some people use a 50 Weight engine oil in the Overdrives (GV type/Laycock design) and
claim good results.
JSeery,

have you ever heard of any time frame for damage to Yellow synchos?
So much discussion on this subject, but no definitive answers.
Jim
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Kahuna,
what do gear vendors recommend for the overdrive?
I ask as their overdrive is a reworked laycock overdrive which was used on loads of British sports cars. Motor oil is usually specified for these. This is due to the nature of the cone clutch which operates the overdrive, this uses friction to "lock" the unit into overdrive. So transmission oil is often too slippery.
Martin.
 
Gear Vender (at least the one I have) requires a special oil that is supplied by GM. It is expensive! I have read that there other oils that can be used but do not perform as well and GV recommends against them.

Fluid capacity 28zo/flat sump or 48oz/deep sump.
Fluid type - GM#1052271 petroleum based or GM#12346190 synthetic.

Mopar synthetic gear lube (Mopar part#04874459) Mineral gear lube is OK, but results in a firmer shift in and out.

These is a twisted tail if you follow it! At one time they used 90 weight oil (which I think is what Volvo recommended). Then for a while ATF. Then the GM fluid non-synthetic, then both non- synthetic and synthetic and the they added the Mopar lube!

I would guess there must be some internal changes in friction material going on to justify these all over the charts lube recommendations!!!
 
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The old Borg Warner overdrives have a roller sprag that acts as a one way clutch so the car can coast free of the gearing to buffer the torque effect between the planet and sun gears. I use Aeroshell 100 mineral (no 100W or 100W plus) aircraft motor oil in my old Mercury transmissions to insure the life of the sprag clutch and the "yellow metal" wear surfaces. The brass blocker rings are affected but there are others too including the main thrust washer in the back of the gear case, the intermediate gear bushing, and the reverse idler gear bushing. Extra pressure additives are acidic in nature and actually eat into the wear surfaces to apply the salts that give the gear teeth the further protection. The soft metals are affected badly if the EP levels are too high.

GL3 was used back in the day but was later superseded by GL4. Stay-Lube GL-4 is a good lube for the old transmissions and is available from a lot of sources.
 
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