Anyone here running motor oil in their 231 TC?

[MoparManiac]

Pretty sure the early NP231s that were used with the CAD front axle had a synchro in them (for 2HI to 4HI)

Not sure if that would affect it at all or not.

 

[Hellbent]

as far as "motor oil in the motor, transmission fluid in the tranny", bear in mind that chrysler's spec for the manual tranny(ax-15) is now motor oil. yup, 10w-30-which i have been running in my ax-15's for the last several years and it's been great(i use synthetic, but it's not required per mopar).

 

[kastein]

that isn't their spec, that's the emergency can't get anything else spec. I run mobil1 10w30 in my AX15 too though... shifts fine.

The actual spec is any GL3 or GL5 that specifies it is yellow metal safe. The only one I could find was pennzoil synchromesh fluid which is a little too rich for my blood.

 

[Hellbent]

i was using redline mt-90 for a while, but it's too hard to find. honestly the amsoil 10-30 i've been using for some time now "feels" a little better anyway.
from what i remember, quite a lot of japanese cars and trucks used motor oil in the trannys for many years too.
i'm guessing it would be fine, although i can't think of any real benefits to using it in a transfer case.....except maybe less emergency fluids to carry if you have a manual trans? or slightly quieter operation if the case in question has a lot of miles? i can't imagine that one over the other would cause any noticeable difference in lifespan.
whatever makes you feel all warm and fuzzy inside, i suppose. :smoker:

 

[tbburg]

that isn't their spec, that's the emergency can't get anything else spec,..

Actually it's the "alternative" spec. Dealerships will fill the trans with it if they don't have the GL- in stock and don't feel bad about it. Some dealerships stopped stocking the GL- fluids and just use the -30.

 

[kastein]

oh really? Wow. Consider me informed, I guess I'll keep using it then!

 

[87manche]

it seems to vary with year/application, but I have seen toyota documentation that the factory spec was 30W oil.

this is for the R series in the tacomas and the like, which is the same trans as the AX-15 with the exception of bellhousing and tailhousing differences.

 

[DanMan2k06]

Had it in my NP231 since the first day I flushed it (about 3 years ago). No ill effects whatsoever. About 50k miles on it since. Regular Pennzoil non-synthetic 5w-30.

 

[sicklet]

I would almosy say that motor oil would be better than atf. Or maybe gear oil designed for Open differentials with no clutch packs.... being that there are no clutches in a 231 I would Imagine that ATF is redundant....or maybe because im a mechanic and I dont trust a word the manufacturer says......examples- dexcool, v8 northstar, Ford lowering the psi rating on firestone tires which resulted in how many deaths?