Synthetic Oil in Rear Axle

[luvrbus]

All gear lube has the GL rating for years we used GL-5 or GL-6 in drop boxes and the rear gear the 6 has been gone the GL-5 is going.

That Mobil 50 is the same oil as the 75-90 the last 2 numbers tell the weight guess what the H stands for are you trying to say a Eaton Roadranger doesn't have gears ?

[bevans6]

the oil that he said was put in the differential is transmission oil, not gear oil.  That's all I am saying.  I like the Delvac 50 weight transmission fluid, I am actually running it in my transmission right now.  An Eaton Roadranger is a transmission, it isn't a differential.  Do you really put 50 weight transmission oil in your differentials?  I put gear oil in differentials, personally...

From the original post:  Rockwell Diff. 3.58 ratio - Delvac Syn Trans Fluid 50w (mbl 98h193)

That is the wrong fluid for that application, as far as I am concerned.

Brian

[gus]

OK, I'm ready to be educated - exactly what does each digit in  (mbl 98h193) stand for?? Those numbers look metric to me because they are odd. SAE numbers are usually multiples of 5. Guess what, I Googled those numbers and the only place they showed up were here!!

I know what GL means, GL-1 to 4 is not extreme pressure, that starts with GL-5. Some diffs use XP and some don't - it all depends. Some steering gears use XP and some don't. My 4104 diff uses GL-4 and so does my 5 ton White dump. My GMC five ton 630s use GL-4 in the diffs and 50W in the trans - it all depends.

Oil weight has nothing to do with the GL rating, weight is basically based on working conditions and temps.

[bevans6]

Having read the Delvac website I don't think the numbers mean a thing except the part number.  It's actually 98HL93, and all that means is a 35 lb container of SAE50 synthetic transmission fluid.   The exact same product in a 105 lb container is 98HL91.  Here are some examples of other part numbers...  http://www.paccar.com/truckaccessories/kenworth/Mobil.htm

If you google the number spelled right, with an L instead of a 1, it works a lot better     I got there by googling the name, not the number, so the 1 instead of the L in the original post didn't matter.

Brian

[jok]

Your right about it being a Part Number.

On my invoice they show the one as 98h193, but the other they show as 98HL98. It would make sense that both would be HL. I didn't catch the difference in their invoice. Good eye Brian.

John

[artvonne]

  Just an FYI, the pdf file for mobil delvac 50 syn trans fluid states it is NOT to be used in hypoid gears under any purposes including topping up.

  Its at the bottom of applications on page 2...

  http://www.imperialoil.ca/Canada-English/Files/Products_Lubes/IOCAENCVLMOMobil_Delvac__Syn_Trans_Fluid_50.pdf

[luvrbus]

I have used it for 6 years and will keep on using things change in oil world in 11 years Paul you know like the Delo 400 vs 100 lol

[bevans6]

Clifford, I am trying to really understand your point here.  Earlier in this conversation you said you used GL-5 or GL-6 fluid in differentials.  GL-5 is the currently a correct rated lube for differentials with hypoid gears, so I completely agree with you on that.  GL-6 has been inactive and not used since 1995, so that is obsolete as you said.

Now you are saying that you use GL-4 rated transmission oil in your differentials, since that is what the Delvac 50Wsynthetic transmission fluid that Jok said was put into his differential is rated at.  GL-4 is rated for helical gears such as are found in transmissions, and the spec sheet specifically says that it is not to be used in hypoid gear applications that require GL-5.

Your statements are taken with great respect here, and by me in particular, so I really want to understand if you use GL-4 transmission fluid in your differentials.  My real concern is that Jok either was told he got the wrong fluid in his diff, or worse - actually DID get the wrong fluid in his diff and needs to get it replaced ASAP.

Thanks, Brian

[luvrbus]

Brian, I been using the stuff for several years I know this topic has Matt on edge because the Eagle he bought from me has it in the drop box and differential has had for 5 years when I installed the 3:36 gears the front and boogie hubs also oil samples came back fantastic every time

I have owned heavy equipment all my life and it will surprise one what they use in the way of oils I have carried that over to the buses over the years never had a failure .

People use anything they want that it is their option not mine I know one thing for sure the oil co's products go far outside the spec's they furnish for publication, the GL-5 rating is going away

[gus]

I copied and pasted the number directly from the post and it sure looks like a lower case l to me.

Most differentials I know of since about 1959 or so are hypoid??

As I said, some of my older truck diffs specifically call for none-XP (GL-4) and I have followed that instruction for years. This was also known in the old days as mineral oil.

My 4104 trans calls for 50W Aviation Grade Oil. This is still available, believe it or not, but is now called engine break-in oil and is labeled Mineral Oil. Of course, since it says Aviation on the label, the price is outrageous.

[artvonne]

  Rather than the Bus manufacturer, I would be curious to know Eaton's opinion on the matter. All I can go by is the oil manufacturer specifically states to not use that oil in hypoid gears.

  Between the Govt., the EPA and the oil companies screwing with oil and oil grades they sure have made it confusing. Seems more and more these days, you need a chemical and mechanical engineering degree just to pick out the right oil.

[bevans6]

OK - being stubborn as a freaking mule, and also being willing to stand up when I get it wrong...  I did a bunch more research.

That Delvac Synthetic 50W trans fluid meets GL-4 specs.  GL-4 is appropriate for certain types of hypoid gear applications, particularly those with limited offset and transaxle applications where the oil is shared with a manual transmission, or a clutch type limited slip.   It contains the EP additives, just slightly different ones and at a lower percentage, compared to GL-5.  GL-5 is recommended for higher off-set hypoid gear differentials and is not recommended where a synchromesh or clutch pack is involved.

So I will stand up and say that Clifford is right, a GL-4 rated fluid can be used safely in the types of differentials that we have on buses and in any manual transmission, synchro or non synchro.  GL-5 might be an upgrade choice in a differential such as we use, but it's strictly speaking not required.  If you have a synchro gearbox or a limited slip diff I would stay away from using GL5 in it.  In all cases follow the manufacturers recommendations, not mine...

Brian

[artvonne]

  GL-5 apparently has a lot of sulfur based additive to provide the higher EP rating, and is known to attack yellow metals such as syncro rings and bushings.

  There is so much push by environmentals to remove all the things they determine to be bad, that I dont believe you can trust even half the information were getting from manufacturers. They are increasingly strong armed into making chemical or engineering changes that effect their product negatively, leaving them to have to BS their products applicability. The continuing reduction of sulfur and zinc from fuel and motor oil, and the engine damage being noted, especially in flat tappet engines, are prime examples of this. Whether it has any real effect on differential and gearbox wear is unknown.

  Some of you guys been around a while in heavy trucks and buses, have you noted any increase in ring and pinion failures?

[artvonne]

http://www.eaton.com/ecm/groups/public/@pub/@eaton/@roadranger/documents/content/rr_tcmt-0021.pdf

  I'm not seeing any recommendation for 50W in drive axles here, maybe someone else can find it.

[bevans6]

50W transmission oil is the same viscosity as 90W gear oil.  They are measured on different scales.

Brian