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conventional. vs. synthetic

NorCalChris

NAXJA Forum User
ive got a 90 cherokee, with 31s. what kind of fluid should i be running in the :motor,transmission, transfer case, and front and rear diffs.

heres why i ask. ive been told that running conventional in my motor is just the same as running synthetic(no obvious gains or losses) then i heard that if i run synthetic in my tranny, it will tend to over heat. as far as transfer case goes, ive yet to ask anyone til today, same goes as for my diffs.
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any help would be greatly appriciated. and if you want to meet me some day at hollister hills, in calif. ill bring the beer and pizza . :chef:
thanks.

-----Chris
 
Motor oil - run whatever you like; use a good filter
Transfer case - run ATF; synthetic or not
AW4 tranny - run Dexron III
Diffs - run 75-90 or 75-140 gear oil
 
the_weirdo is correct. I would recommend using the same dexron III in the transfer case as well.
I have used synthetic gear oil in the diffs with no ill effects, but i have never researched weither or not it was considered "bad" for them or not.
Most people out there will tell you that you can use ATF+4 in your AW4 transmission. Dont listen to them. They assume that its a chrysler transmission. Stick to the Dexron III you will be golden.
The engine works well with synthetic motor oil. I use it just fine. Since your probably running dino oil right now however, expect to get alot of oil leaks after switching. Most get them from their oil pan, oil adapter housing, and valve cover. Just replace the old worn seals and gaskets in these areas, and run a clean engine!
 
norcalchris said:
i either have a leak from my rear main, or from the back of my valve cover. i havent checked it yet. but i just recently got a leak from the front of the engine, and the rear of my tranfer case.


I would certainly fix all the leaks prior to switching to syn or all that expensive syn will just be leaking all over the place.
 
Pick a quality oil and change it every 3k to 5k and get a good filter and you will be fine.

I have seen these engines run over a 100k with the people not changing the oil ever. I do not reccomend that. If you keep it clean and changed the engine will last longer than the rusted out floor your going to have.

Cody
 
I run synthetics in my tranny, transfercase, and difs.
I will in the motor once I get the seals replaced.

Cooler running temps and the fluid looks ALOT better when changing it out. I had grayish almost silt looking sludge in my diffs when running dino. Now the fluid comes out looking just like it did when it went in.
 
w_howey said:
I run synthetics in my tranny, transfercase, and difs.
I will in the motor once I get the seals replaced.

Cooler running temps and the fluid looks ALOT better when changing it out. I had grayish almost silt looking sludge in my diffs when running dino. Now the fluid comes out looking just like it did when it went in.

Do you have the AW4? And are you running AMSOIL Torque-Drive ATF? I bought 12 quarts of it in order to do a complete flush....but I've heard of some people who had problems when they went synthetic in their AW4. Personally, I think their trannies were being held together with gunk, and once they did a flush with synthetic, it went to hell because it was busted to begin with....

Anyway...will I be okay with that Torque-Drive ATF?
 
JNickel101 said:
Do you have the AW4? And are you running AMSOIL Torque-Drive ATF? I bought 12 quarts of it in order to do a complete flush....but I've heard of some people who had problems when they went synthetic in their AW4. Personally, I think their trannies were being held together with gunk, and once they did a flush with synthetic, it went to hell because it was busted to begin with....

Anyway...will I be okay with that Torque-Drive ATF?

I have the AW4, but I used the Synthetic Universal, rather than the Torque-Drive. But that was more because I already had some Universal, so I only needed to buy a another gallon. I haven't had any problems.

The Torque-Drive is Dexron III compliant. When you make the switch, keeping checking the dipstick. I noticed some crud on the dipstick, and drained the pan and swapped in another 4 quarts. You are echoing the things I was able to find about using it in older trannies. It seems to be the most problems are with trannies that were full of junk to begin with......
 
AMSOIL every where oil is required for 100,000 + miles now. Total XJ milage is 238,000 miles.
 
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