manual transmission fluid

[shaggimo]

82 change over year? The 81 had (still has, lol) 10w30 in it, selectable btw. 

[wagoneerhauler]

All this has me wondering if there is a difference in the trans or t-case between when they called for one or the other lubricant.  Meaning, did AMC or the manufacture of the unit make changes (which I doubt) to the internals so that they required one or the other fluid (an oil versus the ATF)?

If they didn't it would seem as the ATF would be better to run if a particular unit used both throughout the years and your year said to use the oil.  I say this because why would AMC have changed to using the tranny fluid if it wasn't better for it.

Anyone follow me here?  Opinions?

[pradtf]

All this has me wondering if there is a difference in the trans or t-case between when they called for one or the other lubricant.  Meaning, did AMC or the manufacture of the unit make changes (which I doubt) to the internals so that they required one or the other fluid (an oil versus the ATF)?

If they didn't it would seem as the ATF would be better to run if a particular unit used both throughout the years and your year said to use the oil.  I say this because why would AMC have changed to using the tranny fluid if it wasn't better for it.

Anyone follow me here?  Opinions?

ya this is a good question for speculation!
here's what amcken wrote earlier:
If you're going to use 10w30, why not use 5w30. It flows better when cold and usually costs the same.

so is it possible that atf has better flow properties than straight motor oil? is it lighter and therefore better suited to gear mechanisms? the speedometer cable hookup to the tc is also plastic, so possibly something lighter is less stressful on that material too?

[rollguy]

Could it be that anything with a viscous coupling requires ATF? 

[IowaEagle]

Just to confuse the issue even more, in 1984 AMC says in its MR  repair/service guide to ONLY use its AMC/Jeep/Renault Transmission Lubricant PN# 89 83 000 000.

Perhaps someone with an '84 or later owner's manual may have what can be used in its place.

If I remember right AMC changed to ATF because the transmissions using 10W 30 were overheating.

[wagoneerhauler]

So it sounds like ATF should be used to replace any oil in the transmissions then.  I wonder how many times it would require draining, filling, driving, draining, filling etc. to flush the oil out.

Is there a consensus on the transfercase lubricant?

[pradtf]

So it sounds like ATF should be used to replace any oil in the transmissions then.  I wonder how many times it would require draining, filling, driving, draining, filling etc. to flush the oil out.

Is there a consensus on the transfercase lubricant?

after reading the replies here and considering that amc switched from motor oil to atf in 1982, that's what we put in yesterday.

 

[AMCKen]

Could it be that anything with a viscous coupling requires ATF? 

AFAIK the viscous coupling fluid has no connection with the main oil. If it does, it's broken. : )

[wagoneerhauler]

So it sounds like ATF should be used to replace any oil in the transmissions then.  I wonder how many times it would require draining, filling, driving, draining, filling etc. to flush the oil out.

Is there a consensus on the transfercase lubricant?

after reading the replies here and considering that amc switched from motor oil to atf in 1982, that's what we put in yesterday.

 

I think you made a good choice.  Are you going to dump it after you get some miles on it and refill?  Let us know how it goes.

[pradtf]

I think you made a good choice.  Are you going to dump it after you get some miles on it and refill?  Let us know how it goes.

i wasn't thinking of dumping and refilling, but now that you mention it, possibly we should. guess that would clean out any remnant motor oil in there. it seemed to be fine with the motor oil in the past, but we hadn't driven it much and there wasn't any leaking. however, it never hurts to change the fluid, so yours is no doubt a good idea.

[IowaEagle]

Yes, there is to be no fluid connection between the transmission and the transfer case.