buck35

Good read with some interesting results
Apparently if you spend enough on advertising you can charge what you want
Borgie what's neo oil?

MILD THUNDER

iTrader: (3)

Seems like in the automotive world, when severe service is anticipated , like towing , hot summer temps, heavier loads, the manufacturers are spec'ing 75w140. Considering they have to warranty these things, I can't see where the thicker oil would cause any damage. It must help if they recommend it.
I've been running the 85w140 in my semi truck rear ends with no issues ...

We all pretty much run mercury drives. And they spec 75w90. However , they also say no synthetic engine oil, have leaky headers, valve train issues, and without a doubt, durablity issues with the bravo drive. So I'm not quite so sure I will take that 75w90 only recommendation to the bank. A 300hp engine with a 3 blade prop on a 19ft bow rider , isn't gonna make the same heat, or sustain the same loads as a 525efi 42ft boat setup. Idk. Maybe I'm way off on this

MILD THUNDER

iTrader: (3)

Anyone every put a temp sender in a bravo drive in a High Performance application? I wonder how hot they actually get fluid temp wise?

So2fast5u

I use 75-140 synthetic from John Deere. It's about $24 a quart. We get it in buckets for the farm. I have no prob yet but i dont have lots of power like u guys.

BUP

iTrader: (9)

Actually Mercruiser High performance gear oil is 80w-90 before that they had Mercury Premium Gear oil. It was the color of maple syrup. Sticky as glue also and was a climbing gear lube.

Also I have the outdrive temp senders / Gauge and all the wire in a complete kit to monitor your outdrive temps. . I am testing the whole set up as we speak and will should have it available very soon to sell..

MILD THUNDER

iTrader: (3)

Really not trying to turn it into a brand debate. I understand what you are saying about shearing and viscosity, etc.

What I am trying to determine, is what, if any, drawbacks would there be to running a thicker oil?

I suppose knowing the operating temp is one consideration. I mean if the drive oil never sees over 200ish, than it may be a waste. But if the drive oil temps are seeing 300 degrees, maybe it might be a consideration? We may know a 90 weight oil is capable of providing the proper viscosity at 210*, but what about at 250, or 300 degrees? Example

Say typical 25ft Baja outlaw with 496 Mag engine, bravo drive, 3 blade mirage prop. His maximum drive oil temp might be 190*. Then you have a guy with a 42 Fountain, with a pair of 525's, running 6 blade hering props. His maximum drive temp might be 290*. It would almost be like a having a F350 dually that never pulls a trailer, and operates in Minnesota all year, compared to the guy who has a F350 dually, that tows a heavy trailer, thru the arizona desert all summer long. Same gears, same housings, but extremely different operating loads and temperatures. My guess is with Ford, Chrysler, Toyota, GM specing 140w gear lube, is that they must believe the 140 isnt gonna cause the damage to the Minnesota truck, even though 90 would work better, where as the 90 might cause damage, in the arizona truck?

I see Neo also makes a 75w140, as well as their 75w90. I'd imagine they make a 75w140 for certain applications. Question is, what is that application? I'd guess that the lube engineer would need to know the operating temp and loads and what not, to specify which oil should be used?

With engine oil I can see where a thicker oil, can cause issues. I wouldnt run straight 50 weight engine oil in a new Z06 Corvette, or something like that with tight clearances, that was designed around using a thin oil. But this is more of your basic standard helical gear lubrication question. Its not like the oil has to flow thru .002 clearances when its 4* and snowing out.

MILD THUNDER

iTrader: (3)

Approved Lubricants - General: Gear lubricants acceptable under military specification (MILSPEC) MIL-L-2105D (Lubricating Oils, Gear, Multipurpose) are approved for use in Eaton Drive Axles. The MIL-L-2105D specification defines performance and viscosity require- ments for multigrade oils. ItIt supersedes both MIL-L-2105B, MIL-L-2105C and cold weather specification MIL-L-10324A. This specification applies to both petroleum-based and synthetic- based gear lubricants if they appear on the most current "Qualified Products List " (QPL-2105) for MIL-L-2105D. NOTE: The use of separate oil additives and/or friction modifiers are not approved for use in Eaton Drive Axles. Approved Lubricants - Synthetic based: Synthetic-based gear lubricants exhibit superior thermal and oxidation stability, and generally degrade at a lower rate
when compared to petroleum- based lubricants. The performance characteristics of these lubricants include extended change intervals, improved fuel economy, better extreme temperature operation, reduced wear and cleaner component appearance. The family of Eaton RoadrangerTM gear lubricants represents a premium quality synthetic lube which fully meets or exceeds the requirements of MIL-L-2105D. These products, available in both 75W-90 and 80W-140, have demonstrated superior performance in com- parison to others qualified under the MILSPEC, as demonstrated by extensive laboratory and field testing. Lube Sampling and Condition Monitoring: For information, contact your local Eaton represen- tation at phone numbers listed on the back cover of this manual. Makeup Lube: Maximum amount of non-synthetic makeup lube is 100%.
Viscosity/Ambient Temperature Recommendations: The following chart lists the various SAE Grades covered by MIL-2105D and the associated ambient temperature range for each. Those SAE Grades shown with an asterisk (*) are available in the Roadranger family of synthetic gear lubricants. The lowest ambient temperatures covered by this chart are -40oF and -40oC. Lubrication recommenda- tions for those applications which consistently operate below this temperature range, must be obtained through the Eaton Corporation, Axle & Brake Division

Grade Ambient Temperature Range 75W -40oF to -15oF (-40oC to -26oC)
75W-80 -40oF to 80oF (-40 oC to 21oC)
75 W-90* -40oF to 100oF (-40oC to 38oC)
75 W-140 -40oF and above (-40oC and above)
80W-90 -15oF to 100oF (-26oC to 38oC)
80W-140* -15oF and above (-26oC and above)
85 W-140 10oF and above (-12oC and above)

This is from Eaton. As they show here, as the temperature changes, so does the lube specification. Same rear end, just different temps

AB69Z

I would like to hear more about the Neo oil

thirdchildhood

iTrader: (6)

Does the sensor go in the upper plug hole? I think that's the only place you would get a meaningful reading.

I worked as a heavy repair auto/light truck mechanic for 20 years. That means engine, transmission, transfer case and drive axle. Rear (and front) drive axles are one of the most durable parts on a car or truck. I saw very few broken drives, even on snow plow rigs. All hold up well and the Ford 9" is indestructible. Lots of older cars are still running with the original oil! It's hard to break a ring or pinion gear even with abuse. I wonder why the change in oil specs now. Especially if it may increase drag.

MILD THUNDER

iTrader: (3)

Very true. In the heavy haul trucking business myself. The rear ends are very durable , and most failures are simply from driver abuse. It's very common to see the rear ends go a million miles with normal service intervals and your basic gear lube. None of these big major fleets are running amsoil, neo, redline, etc. Cars I can't see having as much stress on the rear end. Your typical car production V8 might put out 300 ft lbs of torque, and only stays there for a short time. Otherwise it's consuming minimal power to maintain a steady cruise at 65mph. Now a tow rig hauling a 12k lb boat up a long grade with today's high output diesels, I can see then getting pretty hot and pretty loaded.

However, semi trucks also have large gears, and large bearings. Unlike the bravo drive, which has small gears and small bearings. They probably need all the help they can get. Whether it be a better quality lube, different weight lube, or both, idk.