GL-1 Gear Oil Alternative

[m16ty]

A design issue.. the transmission is a splash system. A change in the casting or some other device to enhance the flow of lube would solve it. It GL-5 isn't getting splashed to the right spots, neither is GL-1. They have the same viscosity (80-90) and other than some additives are the same.

To say that GL-1 flows 'better' than GL-5 is laughable. To say that GL-1 lubricates better is laughable. The base stock is the same, GL-1 simple did not have the additives that GL-5 does... its not like we are talking dino vs synthetic.

I can name several transmissions and transfer cases that had design issues that would cause failures (the T-84 in the jeep would splash all the oil from the T-18 into the T-84) The needle roller bearings in the T-84 input shaft *never* got enough lube and would wear. The L-134 engine in a jeep would rob oil from the main bearings because of the oil filter connection was right there.

Tons of bad designs, none could ever by fixed by changing the lube oil.

Also, you have not given any reason why GL-5 is not acceptable.

Again:

300,000 trucks
20 years
GL-5 in all of them.

By some people standards my 66 should never have made it to 2011 becuase that evil GL-5 should have rotted all the rotating parts.

I invite you to test drive it and see how well it runs.. after 44+ years, and 20 years of GL-5 in the cases.

Nowhere is Stumps post did he say GL-1 flowed better than GL-5. I don't think he even mentioned GL-1 in his whole post.

 

[stancanpara]

Interesting thread... Thanks everyone for your input. I've enjoyed reading everyone's opinion!

Thanks for putting so much thought and time into this Paul (and everyone else).

 

[paulfarber]

Nowhere is Stumps post did he say GL-1 flowed better than GL-5. I don't think he even mentioned GL-1 in his whole post.

You should reread his post:

" GL-5 is not adequately lubricating the 2nd gear's bearing when the truck is going fast in 5th gear. The gear has been modified a couple of times to improve things, as evidenced by the variety of differently designed gears found in actual transmissions, but it still seizes up on many of these trucks. Whenever a gear seizes on a shaft it is a lubrication problem."

GL-1 is straight mineral oil with some anti-foaming additives. GL-5 is the SAME BASE MINERAL OILS with EP and other additives.

How can you claim that GL-5 is no lubricating a gear, yet GL-1 is. THEY ARE THEY SAME BASE STOCK. As long as ANY GL-5 spec oil is reaching a part, I can guarantee you it is doing a better job than GL-1.

As I CORRECTLY stated, if there is INSUFFICIENT lube reaching a part, then the part is designed that way. Again, there are PLENTY of MVs with lube issues (the T-18 intermediate shaft wears because there is insufficient lube reaching the bearings. Ditto for the L134 engine. The front main bearing is starved for oil because the oil filter (a route of less resistance) is robbing oil from the main bearing. Nothing you do short of plugging the oil port to the filter will fix it.

GL-1 is no more slippery, are able to 'reach' places that GL-5 can't as long as they are the same temp, viscosity etc... GL-5 is not like molasses and GL-1 is like water.

 

[Floridianson]

Someone posted they found this at napa.

 

[dburd72]

Pennzoil does list a gear oil for GM & Chrysler manual transmissions called synchromesh that they state is yellow metal safe.

 

[paulfarber]

MT-1 is the 'Yellow Metal Safe' designation.

It actually means 'Manual Transmission' Spec number 1. Really.

GL-5 has been yellow metal safe for decades. Originally there was an issue with water, sulphur and heat above 250F. Any tranny/transfer with an operating temp above 250F requires synthetic oil because it does not contain the exact same additives as mineral oil GL-5 spec.

If you look closely at that NAPA pic, you will not see an API specification logo... it may be on the other side.. but 99% of the time its on the front.

 

[Floridianson]

Diesel and Vehicle Transmissions, Synthetic Transmission Fluid - DeloThere is this.

The pic has the API MT1 on the front. middle way down left side.

 

[m16ty]

Actually, Paul it would strongly appear that you are wrong. GL-5 is not adequately lubricating the 2nd gear's bearing when the truck is going fast in 5th gear. The gear has been modified a couple of times to improve things, as evidenced by the variety of differently designed gears found in actual transmissions, but it still seizes up on many of these trucks. Whenever a gear seizes on a shaft it is a lubrication problem.

Ask M35tom about it. He has spent a lot of time inside of these transmissions in his quest to manufacture a slightly faster overdrive 5th gear. He has found that SAE40 is an even better fit than the SAE50 motor oil that both Rockwell and Meritor recommend for this transmission.

But again, I will repeat myself: ... you don't need our approval to justify your choice of using GL5 in your deuce. Even though many of us think it is suboptimal, it is probably the right thing for you.

-Chuck

You should reread his post:

Paul, I just did and quoted it here for you to see. I stand by what I said, " Nowhere in Stumps post did he say GL-1 flowed better than GL-5". GL-1 is not even mentioned in his whole post.

 

[Coal Cracker]

Someone posted they found this at napa.

Yes I posted this in a thread I started on what I thought was a better trans/ t-case lube. I'm now eating crow, and went back to GL-1.

 

[bassetdeuce]

For GL1 (pure mineral oil / no EP additives): NAPA 65-205 for 5 gallon pail, and I think there is another, NAPA 65-201 for 1 gallon jug.

Good enough for me, though I wonder who else uses this stuff besides MV owners, and farmers with old tractors. I know, who cares?

 

[Countryboy21]

so whats the final say on what type of oil to use in the engine, trans, transfer, and diff. just want to see if that info can be placed some were for easy reference for new people like me!

 

[bassetdeuce]

so whats the final say on what type of oil to use in the engine, trans, transfer, and diff. just want to see if that info can be placed some were for easy reference for new people like me!

If ya want to keep it simple, 15w40 HD oil for the engine (whatever is cheap, or the coolest lookin bottle), and the afore mentioned NAPA GL-1 for trans, transfer, and all 3 diffs. I don't know about your budget, but as far as I'm concerned the capacities of these trucks are too much for $$ magical lubes.

 

[Countryboy21]

i buy from a truck parts distributor for everything he get parts to me for 1/2 the price of napa parts. so 6 qts in the diff X 3 is 18 qt + trans ? qt + transfer ? qt = like 8 gallons right ? LOL

 

[paulfarber]

Really grasping at straws to cling to the GL-5 is bad for you myth?

The statement was that GL-5 is the cause for the gear to fail, and they redesigned the gear several times... but that mean old GL-5 simply will not lubricate the gear as well as GL-1 did.

BULL HOCKEY.

Unless you have some drawings or engineering reports?

As I stated, and you glossed over, there are MULTITUDES of bad designs in MVs. Reference the Go Devil L134 jeep engine and the jeep transfer case. That's what I know of..... I'm sure there are tons of other examples but I own a jeep so I know that specifically.

GL-1 is the same thing as GL-5.. they both use a base mineral oil. The Gl-5 has EP additives (that means it has more lubricating additives that GL-1 which only contains some anti-foaming stuff).

Transmissions are splash lubed. There may have been a very real cause for no lube splashing into the spot they needed it to go to... but if you have two oils, the same temp, viscosity, etc but 1 is GL-1 and the other is GL-5 if you believe that the reason the gears were failing was because the GL-5 was not lubricating it 'enough' then GL-1 was also not because they are, essentially, the exact same thing. GL-5 specs are in addition to the GL-1 specs. So everything GL-1 can do, GL-5 can do it, and more.

If you want to parse every noun and verb fine, have at it.. but I would not further pursue this train of thought... it makes absolutely no sense.

 

[bassetdeuce]

i buy from a truck parts distributor for everything he get parts to me for 1/2 the price of napa parts. so 6 qts in the diff X 3 is 18 qt + trans ? qt + transfer ? qt = like 8 gallons right ? LOL

Understood. I guess I speak for those that have to feed a fleet of trucks. Total costs add up quickly, so cheapa is betta.

 

[mobileauto2000]

All i know is i drained the GL5 out of my trans and put in 40w motor oil and i no longer have to fight it into first or second gear. If your trany is hard to shift dump the GL5. Synchros work like clutches or brakes. they ether speed up or slow down the gears so they mesh. The friction modifiers Can (not always) keep the synchros from working right. To much slip.

 

[m16ty]

so whats the final say on what type of oil to use in the engine, trans, transfer, and diff. just want to see if that info can be placed some were for easy reference for new people like me!

I honestly don't think there will be a final say. It is akin to the Ford vs Chevy debate. The best thing I can tell you is to do your research and use whatever you feel comfortable with.

All I could do is tell you what I use but there are some that will say I'm dead wrong.

 

[steelypip]

All i know is i drained the GL5 out of my trans and put in 40w motor oil and i no longer have to fight it into first or second gear. If your trany is hard to shift dump the GL5. Synchros work like clutches or brakes. they ether speed up or slow down the gears so they mesh. The friction modifiers Can (not always) keep the synchros from working right. To much slip.

This is a completely different problem from insufficient lubrication. Incidentally, the common fix for transmissions that require GL-2 or later (EP) oils and have weak synchros or poor synchronizer action is to switch to synthetic GL-5. It has a lower viscosity at rest which tends to help the synchros work better.

 

[mobileauto2000]

This is a completely different problem from insufficient lubrication. Incidentally, the common fix for transmissions that require GL-2 or later (EP) oils and have weak synchros or poor synchronizer action is to switch to synthetic GL-5. It has a lower viscosity at rest which tends to help the synchros work better.

I understand what your saying. but this thread is what is the best or right oil to use. I am stating what my experience has been. 40w oil is an approved lube for these tranys. I put it in and it fixed my shifting problems.

Also there is some who think its the friction modifiers that cause the problem with the high speed bearings. I have no opinion on that. My experience on vehicles coming through my shop is more often related to wrong lube used by do it your selfers. Thay dont relaize that 90w gear oil they had in the shed just wont work in most modern transmissions.

 

[wcolt45]

I'll second that mobileauto,switched to Rotella straight 40w and my truck shifts MUCH better,and IS approved for use.