zeep99xj

I need to change my oil so i thought id just change most of the other fluids while im at it since im sure it has never been done before on my jeep. Heres what i want to change and what i do and dont know about the different fluids and such.

Engine oil- I am not sure what oil i want to run because i have heard so many different opinions. I read something about SJ, SM and SL ratings on here but i cant seem to find the thread again. So could someone enlighten me on that subject?

Tranny and T case fluid- My manual tells me to run Dexron II but from my understanding that isnt available anymore so Dexron III will work the same wont it? And as far as draining and replacing the fluids i can just drain through the drain plug and fill through the fill hole right? I read a few sites that talked about removing the pan but isnt that unnecessary?

Differential fluid- Im pretty sure i need SAE 75W-90 for my dana 30 and 35 axles. The manual does state that if i have a towing package to use SAE 75W-140 in the rear but i took the hitch off so should i stick with the 90 in back? I am not sure if i have LSD but i will test and find out before i start the change (isnt it if you spin one tire and the opposite tire spins with it you have an LSD, or am i way off?) If i do have a limited slip what additive do yall suggest? And finally when reinstalling the housings should i buy a new gasket or just use a silicone adhesive?

I know theres alot to answer but thanks for any help and suggestions. I have done quite a bit of research on this i just want to clear it all up with the pros

Militaryman4455

I can tell you that I use Mobil 1 synthetic high mileage and mopar filter and they work great... Dont use silocone adhesive for a gasket... Get gasket maker... Maybe thats what you meant. Hope that helps some.

zeep99xj

So something like this? http://www.oreillyauto.com/site/c/de...rs+%26+sealers

Militaryman4455

No... Something like this... I use ultra red...

No4x4Yet

The colors arent just colors. Each color has different properties. Some are high heat, some are sensor safe. Make sure you get the right stuff.

Militaryman4455

Well I stand corrected! Thank you for that info... Do you know what the red is good for?

No4x4Yet

No idea but they all list the properties/uses right on the package.

1991Jeep_Man

Red is mainly for high heat areas. I used some on my Valve Cover gasket. Used for oil pans, vc's, etc.

I also had blue RTV. Used for sensor safe thermostat housings, water pumps, etc.

zeep99xj

So it looks like i need permatex gear oil rtv sealant for the differential casings and permatex ultra black for the transmission pan if i do a tranny fluid filter swap. Does anyone have any write ups that could show me how to do the filter swap?

zeep99xj

As far as the gear oil would it hurt to run the 75W-140 in the rear if i dont have the tow package. Or would that be a safe way to go?

Militaryman4455

If the axle is rated for it then it is safe to run it... Honestly, I think that its "safe" to run that weight even in the front, its just not ideal.