I’m installing a Strange S-Trac helical gear differential in my 2014 Mustang GT. Strange recommends petroleum-based 85W-140 with no added friction modifier. They state synthetic gear oil will adversely affect unit operation and void warranty. Would additional wear or improper operation occur if using AMSOIL 75W-140 Synthetic oil with friction modifier opposed to just Lucas Oil 85W-140 petroleum-based oil, which is what Strange recommends.
Synthetic oil in Traditional oil differential
- Thread starter Travis4x4
- Start date
You know, sometimes you just have to wonder.
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"Strange recommends petroleum-based 85W-140 with no added friction modifier. They state synthetic gear oil will adversely affect unit operation and void warranty."
↑↑↑↑↑ Do this right here and be done with it. If you don't and it messes up......it's yours. ↑↑↑↑↑
↑↑↑↑↑ Do this right here and be done with it. If you don't and it messes up......it's yours. ↑↑↑↑↑
If Strange recommended synthetic, would you use conventional?
DO NOT USE SYNTHETIC GEAR OIL
Will adversely affect unit operation and void warranty
Notice how Strange capitalized the "DO NOT USE SYNTHETIC GEAR OIL".
Looks to me like they feel strongly about using conventional.
Will adversely affect unit operation and void warranty
Notice how Strange capitalized the "DO NOT USE SYNTHETIC GEAR OIL".
Looks to me like they feel strongly about using conventional.
It’s a helical gear which is similar to a worm gear. Yeah I figured so I’m going with Lucas 85W-140 conventional oil.
MolaKule
Staff member
It is a Torsen design so they want you to use a conventional (mineral) GL-5 differential lube.
What is interesting historically is that no Torsen manf. that I am aware of has ever published any torque data showing differences between mineral oil diffy lubes and synthetic lubes and their engineering reasoning behind the lube selection.
I would select a SuperTech or a Valvoline diffy lube any day over Lucas.
It does incorporate a "Worm-Gear" type system but is a bit more involved.
What is interesting historically is that no Torsen manf. that I am aware of has ever published any torque data showing differences between mineral oil diffy lubes and synthetic lubes and their engineering reasoning behind the lube selection.
I would select a SuperTech or a Valvoline diffy lube any day over Lucas.
It does incorporate a "Worm-Gear" type system but is a bit more involved.
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Its a interesting design.
I heard the Lucas is snake oil .. Would it they be better at protecting then Lucas?
Travis4x4 - Yes follow their recommendation.
BUT what is the engineering reason? Is there an actual technical reason?
WE are left hanging. No coconut filling in the coconut bun. Just tissue stuffing. No creme in the Twinkie. No cash in the account.
Travis4x4 - please can you ask Strange why EXACTLY??? In detail. Thank you.
Likely there is yellow bushings on all those worms ...also looks like that is a shearing torture box that needs buku heavy oil to start with.
The only reason I can think of is the higher pressure-viscosity coefficient of conventional oils may provide a greater barrier/thickening under high shock loads. I've inquired Strange a few times on this issue, and they never have a good reason behind their conventional recommendation. Just "that's just what it needs."
MolaKule
Staff member
Eaton states that for their TrueTrac differential you can use a synthetic OR mineral 75W90/80W90 GL-5 gear lube, and of course since it is another flavor of the Torque Sensing technology, it doesn't need the LSD friction modifier.
MolaKule
Staff member
I don't think bronze bushings or bearings would be able to take the loads encountered. I have never seen any yellow-metal components in a modern differential nor in an axle assembly.
4WD
$50 site donor 2024
Well, as an example Eaton will supply differential components to AAM who supplies GM or ?My understanding is it’s recommended for certain applications such as hypoid, spur, bevel, helical, spiral-bevel and worm gears in differentials.
As to why I still don’t know.
Synthetics typically out perform mineral (conventional) oils.
And someone (engineer) has to specify a lubricant that works for all components between the left wheel and right wheel.
if running conventional … be prepared to change on the severe schedule
Not sure either of those has any bearing on selection of base oil. Yes esters will chelate some metals, doesn't mean it will corrode them. Formulators test for yellow metal (brass, bronze, copper) compatibility Needs a higher vis by design, ok but still???
