i recently changed all my fluids(eng.,tranny,transfer case,diffs) over to royal purple synthetic. from all i've read, 75w90 in the tranny and dexron II or better in the transfer case. that's what i'm running and everything shifts much better than before! as far as the gaskets, i've done both(with and without). the only advice i can give is use something like permatex silicone, not "old yellow" weather stripping goo like we used back in the day. i'm sure someone else can add something else, but i've had good luck with this and none of my gaskets(engine or drivetrain) have ever leaked when silicone was used(gasket or not). hope this helps!!!
The transfer case takes ATF +4, Castrol, Amsoil, they all make it, synthetic..Do not run the new Dexron VI in it, their web site says its not for trans that require ATF+4...don't know why but that's what they said
in your yj the t case takes about any atf, dexron/mercon atf +3 +4 its all ok for the t case
manual trans is important, you need a synthetic gear lube, or a syncromesh fluid, 75w90, 80w90 is fine, i've also heard people using 30 and 50 weight motor oil. i remember doing that in my old ax5 after the synchros started going bad and it helped the shifting. regular gear lube that is recomended is not safe for brass synchros. the manuals are wrong, and there's a ton of ax5 and ax15 transes all over with bad synchros.
i always use rtv on the diff covers, you can buy gaskets if you want, but rtv is more common.
WOW--I never heard of using motor oil in trans---you'd think that thick stuff would interfere with efficient power distribution----but when you are talking about the internals (synchros etc) it sounds like a good thing.
I've caught Chilton (more that Haynes) giving inaccurate info before...
I don't have a moral/ethical prob with fossil fuels at this moment but have considered a synthetic conversion often. It just seems like a giant leap for me. In my J10 when I installed a new steering box and lines, I swithced that component to synthtic power steering fluid. Noticed no difference, it was the same price, so I never considered synthetic again.
Someday I will research the pros and cons of synth.
I'll deviate from Chilton's/Chrysler recommendations if I get some good advice. What are you doing in your own rig for motor oil/tranny/transfer case/diffs?
I'll deviate from Chilton's/Chrysler recommendations if I get some good advice. What are you doing in your own rig for motor oil/tranny/transfer case/diffs?
chrysler/chiltons manuals are wrong, anyone will verify that. i'm a mechanic and the computer program we use at work says the same thing, and they're wrong. personally i will use an 80w90 gear lube that is synthetic, that states ok for brass synchros, or equivilant in the ax15 i'm building. and i am not a synthetic lube person, i don't run anything synthetic.
motor oil i use valvoline max life 10w30, and transfer case i use whatever atf i have around, which is usually atf+4 anyway. diffs i use regular 80w90 for regular open diffs, and i have 85w140 in my comanche for towing.
if you wheel your jeep, you'll want to change diff fluids at least once a year, sometimes more. synthetic in axles that are wheeled seems like a waste to me.
I like my Jeeps.
I've been religious about ALL fluids, especially trans/tc/diffs in my J10 yearly.
One question while you are here (and thanks for being patient with me, Dave).
Why is the YJ fuel filter so expensive? I'm used to paying 3 bucks. Napa/Checker stuff is close to $15 bucks for the YJ...
--PS--that is a beuatiful Commanche in yr profile. Is that an AMC or Chrysler or Renault? There's a ton of these in northern az but none as kept up as that picture. It's awesome looking. I already know it's dependable!
I like my Jeeps.
I've been religious about ALL fluids, especially trans/tc/diffs in my J10 yearly.
One question while you are here (and thanks for being patient with me, Dave).
Why is the YJ fuel filter so expensive? I'm used to paying 3 bucks. Napa/Checker stuff is close to $15 bucks for the YJ...
--PS--that is a beuatiful Commanche in yr profile. Is that an AMC or Chrysler or Renault? There's a ton of these in northern az but none as kept up as that picture. It's awesome looking. I already know it's dependable!
thanks for the compliment on the mj, its a 1990 so its renix era, i love the crap out of it, i picked it up pretty cheap, and i've done some work to it. i recently picked up a second one also. i'd love to find a super clean one in arizona, they're out there. having a pickup is great, and you're right, it is reliable just like any jeep, its a renix 4.0.
anywho, fuel filters these days are around 10-15 bux, these are mounted on the frame and not the little old things that carburetors used.
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