Fluid type in doubler case

[Evan]

What type of fluid would you guys recommend running in a doubler case? I have been using ATF as that's what is normally run in a BW1350, but I was thinking since this is more of a "passive" lubrication (no pump) that it would be better to run gear oil in the case. Thoughts?

 

[metalmacguyver]

I would stick with the ATF because it is thinner and will get into the bearings and stuff better than gear lube. The bearing I would be most worried about is the needle bearing inside the planetary setup. You should worry about that too because the most expensive part of the doubler (the sector shaft) rides on that needle bearing.

IMHO.....stay with ATF.

 

[CopyKat]

0W30 synthetic motor oil. That what I run in mine

 

[metalmacguyver]

Why?

 

[4x4junkie]

Mercon ATF seems fine.

I have mine filled so the gears are about 1/3-2/5ths submerged. Probably coming up around 7000 miles on the freeways and no problems. Fluid was still bright pink last time I checked it.

 

[F150hybred]

I'm with CopyKat on this one. 0W30 has the same specific weight as ATF... but without all the detergents. Also, ATF is only "modified" hydraulic oil. The 0W30 synthetic engine oil will give you an actual lubricating barrier. Food for thought is all... your gonna do what your gonna do.

 

[4x4junkie]

Lol, if ATF didn't have a lubricating barrier, I think 99% of the vehicles currently on the road would be sittin over on the side with seized up transmissions.

However I certainly don't see any harm coming from using synthetic motor oil in it either (or even regular gear oil).

To each his own though.

 

[Evan]

Thanks for your input everyone. I think I'll keep running ATF as that has worked well so far. It sounds to me like motor oil, gear oil, and ATF all adequately lubricate a doubler case. One is probably the best, but unless we did an in-depth test we'll never know.

 

[surffishin07]

just remember that temp can have a big part of this the hotter the lubricant is the thinner it becomes gear oil is great in places like Texas 0w30 up north because oil has less breakdown in colder weather and atf everywhere