Those of you running a Detroit/Eaton Truetrac...

[Cvcoda]

The manufacturer does not recommend synthetic gear oil with the Truetrac but I've already filled it with the Lucas synthetic 75w-90.

Is synthetic going to do damage somehow or can I run it?

-Chris


Sent from my iPhone using Tapatalk

 

[bronconut73]

Oops...Mine has Royal Purple in it.
Been in there about 4 years though. All good.

The additional friction from dino oil may help load up the gears and transfer torque to the other wheel quicker.

 

[sykanr0ng]

The additional friction from dino oil may help load up the gears and transfer torque to the other wheel quicker.

/\/\ That's why they say not to use synthetic.

While it won't damage them much it reduces the effectiveness, which might in the long run cause a little extra wear from slippage.

 

[Cvcoda]

/\/\ That's why they say not to use synthetic.



While it won't damage them much it reduces the effectiveness, which might in the long run cause a little extra wear from slippage.

Thanks for the info. What's best to run if not using synthetic?


Sent from my iPhone using Tapatalk

 

[Joe473]

I have to ask.. how are the on road/off road manners of these vs the Auburn and other LSD's

Sent from my SM-G900V using Tapatalk

 

[Cvcoda]

I have to ask.. how are the on road/off road manners of these vs the Auburn and other LSD's

Sent from my SM-G900V using Tapatalk

Mine hasn't been on the road since install, so I can't say. But from what I've read, the street manners are excellent, very quiet and smooth. People who use them on the strip say they shoot straight as an arrow. The one negative thing I've read about off-roading with one is that if you get a wheel in the air, the power won't transfer to the other wheel - you have to tap the brakes.


Sent from my iPhone using Tapatalk

 

[Skiddy]

The one negative thing I've read about off-roading with one is that if you get a wheel in the air, the power won't transfer to the other wheel - you have to tap the brakes.


Sent from my iPhone using Tapatalk

that is true, I thought I would have to use my brake a lot when four wheeling it actually locked up more than I would have thought. only had to use the brake a few times, and I am not easy on it;D

 

[sykanr0ng]

Thanks for the info. What's best to run if not using synthetic?


Sent from my iPhone using Tapatalk

A mineral based GL5 gear oil without friction modifiers (yeah, they are kinda rare).
Motorcraft 80w90 was mentioned as one on bobistheoilguy.com

 

[charlie6976]

Moser Engineering recommends Moto 300 75w90 Full Synthetic Oil in the Truetracs
they sell.

Truetracs do not use friction in their operation.

 

[Cvcoda]

I did a little more research and here's what I found, directly from the Eaton site:

http://www.eaton.eu/ecm/idcplg?IdcS...veAs=0&Rendition=Primary&dDocName=PCT_1087652

"High quality mineral or synthetic gear lubes are required for use in Detroit Truetrac differentials. Regardless of the lube type, always use a GL5 rated lube with the least amount of friction modifier. Mineral lubes lacking friction modifiers (limited-slip additives) were historically recommended for all Truetrac applications because friction modifiers can slightly reduce the bias ratio (limited-slip aggressiveness) of Truetrac differentials. However, to address the continually increasing power outputs of modern powertrains, many vehicle manufacturers have switched to synthetic lubricants as a counter measure for increased axle temperatures and prolonged service intervals. In general, consult the vehicle owner's manual for the manufacturer's recommendations for lubrication type, weight and fill volume. This will ensure lube compatibility with the seal materials and bearings used in the axle. Eaton Performance technical support is available for any concerns in lube selection."

I must have read an earlier version of their owner's manual that said they recommend mineral oil only for the Truetrac. And the Lucas 75w-90 gear oil exceeds GL-5 spec.

-Chris


Sent from my iPhone using Tapatalk

 

[bronconut73]

No worries Bud.

I am using Royal Purple in the front so I recognize what oil is leaking. If the leak is purple then it's the front diff.
Not running it in the engine.

Dark brown would be engine
Red would be tranny
Light brown would be rear differential
Purple would be front differential
Clear is power steering.

No leaks though.

Silly, I know....Lol.

 

[Cvcoda]

No leaks though.

Silly, I know....Lol.

That's impressive!




Sent from my iPhone using Tapatalk

 

[bmc69]

I have to ask.. how are the on road/off road manners of these vs the Auburn and other LSD's

Sent from my SM-G900V using Tapatalk

Hands down the best of all of them. I say that as someone who has run all of the others too. Auburn was once my first choice - I've run them for probably 25 years, in various rigs and that's what is in teh back of my '78 Bronco now - but they've been relegated to 2nd place for me, as far as LS difs go.

 

[sykanr0ng]

Moser Engineering recommends Moto 300 75w90 Full Synthetic Oil in the Truetracs
they sell.

Truetracs do not use friction in their operation.

Not entirely correct, it relies on the co-efficient of friction between the helical gears and the case for the torque bias.
Changing the oil changes the friction co-efficient.

 

[charlie6976]

sykanrOng
I was overly vague. I was trying to distinguish/show a difference between the Truetrac and diffs using clutches and friction modifiers. The Truetrac uses no modifier and is basically maintenance free. Subject to further scrutiny.