Fluid for a Detroit Locker???

[Smitty]

Finished putting a locker in the back of my '56 last night. I've been running synthetic fluid in all of my gear boxes and differentials for a long time. Will there be any disadvantages to running synthetic fluid with the locker? The instructions say to run the factory fluid, but nothing that I've owned ever came from the factory with synthetic.

 

[DPI]

Yeah, it will make it last longer! And probably work better...

I've ran synthetic fluid with my rear Detroit for 4 years and it's still going strong...

 

[mrk5]

I've started running synthetic motor oil, brake fluid and power steering fluid, and I plan to switch everything to synthetic. Including the rear diff with detroit.

I figure with all the fuel my truck uses, at least I can help cut some oil consumption by going to synthetics.

IIRC my parents new Expedition uses synthetics in everything.

 

[readymix]

I e-mailed TracTech about the same thing not too long ago. Here is the exact reply. Dated 7/11/2005

Tractech's official word is use what ever you like as long as it is high
quality. My own opinion is that the petroleum oils do a better job in rear
axles.


Brent Bussell
Detroit Locker
Senior Account Administrator
Application Technician
[email protected]
800-328-3850 Toll Free
248-776-5712 Direct
248-776-5792 Direct Fax
248-776-5700 Local
248-776-5702 Company Fax
5712 Extension
www.detroitlocker.com

 

[JonV]

Synthetics work well from low temperatures to high temperatures, and have high oxidation rates (last a long time). However they don't carry heavy loads. High quality enhanced petroleum products are excellent choices for hard offroad use.

 

[89GMCSuburban]

Hmmm? Synthetics find leaks better than conventional oil. Dino oil's molecules are different sizes so in an oil leak, the large molecules will stack up and stop the leak. Synthetic, molecules are the same size, so you actually find more oil leaks with it. When you switch to synthetic, check your oil level OFTEN. You put it in an older engine and it can eat it faster than the normal stuff.

My opinion? Dino oil in rear. You are going to have to change it every time you dunk the axle anyway, and I don't think you want to be spending that much cash...

 

[89GMCSuburban]

Synthetics don't carry heavy loads? Freightliner has put synthetic in their transmissions (Eaton/Spicer and Meritor) and axles (DS404, Meritor, Mercedes) since the late 90's from the factory.