GL 1 oil

D. Jones

D. Jones

Well-known member
Anyone know where I might find information about the applications of the different rated gear oils specifically GL-1 and GL-4. I need to replace the oil in a 1953 Cat motor grader transmission though it is non-syncromesh it does have brass bushings in it so no GL-5. The operators manual says to use an oil that conforms to Mil-L-2105 or straight mineral transmission oil which ever is most convenient. Since it holds 8 gallons and GL- 4 costs around $50.00 a gallon here I'm wanting to use GL-1 which is a mineral transmission oil and can be bought easily and cheaply.

Any help would be appreciated.
 
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Here is an excellent video on this topic. If you are interested in only the gear oil GL information and flow characteristics start the video at 12:00. The earlier part of the video deals with a destroyed transmission repair.

https://www.youtube.com/watch?v=Z7NpsMZ9pBQ

I use this GL4 Gear Oil. When I bought it online on 5/19/2017 the price was $9.83 per gal + $14.85 for shipping + Handling Charge of $1.95 + $1.61 Tax for a grand total of $28.48.Price has more than doubled since then. Hope you find some cheaper vendor.
https://www.finditparts.com/search?utf8=✓&s=stalube+sl24238&commit=

If you have Amazon Prime shipping is FREE.
https://www.amazon.com/s?k=gl4+gear...0&ref=pd_sl_8mg5skwrim_b&tag=atomicindus08-20
 
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If I were you I would contact Petersen Cat in Redmond. I believe their facility is near the airport. Your blade is worth too much to take a short cut............
 
API specification GL1 is basically almost straight refined mineral based lubricant. It's designed for slow moving low pressure gears and worm drives like tractors and really old truck rear axles. I don't think they put much of any "Extra Pressure" EP additives in it. GL3 with mild EP additives was obsoleted by GL4 many years ago but GL4 still a good gear lube for older cars with non hypoid gears and phosphor bronze type gear bushings. GL5 has EP amounts high enough to work well with hypoid type gear sets and high pressure gear sets. The acidic quality of the EP additives can be harmful to phosphor bronze gear bushings. There are other ratings too but they are mostly for specialized rear axles with limited slip type clutch packs in them.
https://www.engineersedge.com/gears/gears_lubrication_general.htm
 
I don't know what Cat specified compared to Ford, but the Ford lubrication charts list a mild EP gear lubricate, today that would be GL-4. Here is a 41 chart calling for mild EP.

GL-4 is listed as Mil-L-2105 quality, what ever that means.
 

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Andy said:
Tractor Supply. I put in my 39 box and it shifted much better.
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50fordcoupeman said:
If I were you I would contact Petersen Cat in Redmond. I believe their facility is near the airport. Your blade is worth too much to take a short cut............
Click to expand...

No tractor supply here and I'm not sure what you put in your transmission.

I've talked with Peterson Cat they had no one that knew what to use but they would be happy to sell me what they have in the way of transmission lube. They're great folks and have been extremely helpful but just don't know in this case.

After reading the "Engineers Edge" review I believe that the original operators manual reference to "mineral oil gear lube" is in fact what is now GL1. I'm going to check further on this.

Too many facts or maybe opinions in this situation are just causing me more worry about what I need to do and getting it right. Yes I could just buy GL4 and use it but I'm not spending my money as the machine doesn't belong to me I'm just the wrench and operator for a non-profit group.

Thanks to all for your thoughts and suggestions.
 
The original MIL spec for gear lube all carried the 2105 designation so that alone isn't a very good indicator. I'd say that older slow moving heavy equipment would likely use GL1 spec lubricant. Where it gets confusing is when they tell you to use MT1 which is a GL5 spec for non synchro transmissions in busses & trucks. They say it is backward compatible with GL1 but I think they are full of it too. I wouldn't be as worried about the synchro blockers as I would the gear bushings and thrust washers.

SAE-90 GL1 or a good quality SAE-50 motor oil would work since both are the same basic viscosity. They're just rated using different equipment. GL1 with a good anti corrosion additive would be the one to find for the price. A person may have to order a drum of it to get some for a good price. It's all expensive now days.

All the old tractors used GL1.
 
GL-4 is what you likely need. GL-5 is rumored to not play well with brass/bronze. GL-4 is friendly with old stuff. Summit has GL-4 80w90 PennGrade for $8.99/qt.

Some gear oil has a GL-4/GL-5 rating... which I 'assume' means it will play nice with older stuff, but still offers the strength of the GL-5 rating.

Below is the PennGrade GL-4 80w90. It's pretty good stuff, and has good reviews. It's also GREEN, so you know if/when it's leaking. lol

This Brad Penn PennGrade multipurpose Classic GL-4 gear oil is specially blended using high-quality PennGrade mineral base stocks and select additive technologies. It is designed to be used with yellow metallurgy (brass, bronze, copper) and other soft metals used in synchronizers, bushings, thrust washers, and other components typically found in classic manual transmissions and transaxles.

https://www.summitracing.com/parts/bpo-77296

bpo-77296_ml.jpg
 
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I just got off the phone with Warren Lube tech support and they told me that their GL-1 was what I should use. Hope they're right as I'm going to buy quite a bit of it as the transmission needs just over eight gallons and I need to flush and refill it.

Thanks to all for your input.
 
Ordered 10 gallons of 90 wt GL-1 from NAPA and will flush and refill the transmission case in the next few days. Need to build a hex wrench to remove the drain plug before I can drain it. I'm hoping to reinstall the engine in the next week or so and then put the old girl back to work. Last week we had a real toad strangler of a rain storm and now have some damage to the roads and ditches that need attention so I really do need to get this repair finished.
 
D. Jones said:
Need to build a hex wrench to remove the drain plug before I can drain it.
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I’m not sure what you have planned for building a hex wrench , but I have had good luck welding a nut and bolt together and used a wrench or socket in the past . Quick and easy
 
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