i have an 00' xj. i have recently flushed the cooling system, changed to amsoil 10w30 oil, and went over jeep completly. my ?? is the axle, trans. case and tranny oil. jeep has 119k, and i am now driving about 55 miles on the interstate to work. what are you experiences with the tranny flush, and running amsoil in everything. i know on some vehicles it is best not to flush the tranny, just change the oil. any advice, thanks

 

i think 80 or 90w gear oil for the diffs. not sure if theres something different to use with that many miles though. i think OEM fluid in the trans is ATF3 and from what I've heard people refill it with dextron mercron 3, could be wrong though and I don't really know the differences between the two. tcase gets ATF as well.

 

i have the owners manual for the common stuff, its really the tranny that worries me. i have always had them flushed on previous vehicles, but on some, like the ford superduty i just sold, everyone said on those if you had it flushed it would put all the contaminates back into the tranny and cause more harm than good, but i always thought the purpose of the expensive flush was to get all the old fluid, and contaminates out.
i was just wanting to see if anyone else has had theres flushed, and or using amsoil for a while now with no problems.

 

Never had mine flushed, only changed it.

 

i need to service mine but I'm not sure whether I should just change the fluid or have it flushed completely. so I've just been putting it off, only have 92k miles on mine though. not sure if the PO serviced it at all.

 

Just have it changed, or do it your self.If you don't know how the PO took care of it start takeing care of it now.

 

well i have a general oil question as well. i have a 1994 xj. all original main parts (engine and transmission) and i put penzoil high mileage in it cus its got 146k. is this a good oil to put in this engine? im just tryin to take care of it as best as possible. also...as far as i know the transmission oil has never been changed. should i change it? the level of it is fine. but should i change it or how do i know if i need to?

 

that oil should be fine, and i would at least change the tranny oil, and filter. the full flush in my mind is not needed, but that was the pupose of the post, i just wanted opinions on what everyone has done and had good luck with in the past. it wouldnt hurt to change every fluid in your jeep with that many miles. i even changed my "black" in color brake fluid, and i could tell a difference. and i would do a full coolant flush as well, using a new radiator hose to drain the coolant, dont use the petcock, it will prolly break.

 

If the tranny is an automatic ... do *NOT* fill with ATF +3 fluid.



I don't care what any service bulletins say -- fill the trans with Dexron fluid.



If you are considering synthetics (like say more Amsoil) ... then the universal ATF will be fine for you.



Personally, I'm not a fan of the "power flushes" that are marketed. What I like to do is disconnect the line to the tranny cooler and stick it in a bucket. Have an assistant start the engine (preferably a good looking woman) while you are filling the trans. As the dirty fluid spits out of the disconnected hose, you are replenishing with fresh stuff. When the fluid comes out clean ... shut the engine off. Reconnect the hose and then check fluid levels (engine running again, obviously).



You do "use" a lot more fluid this way --- but it's the safest way to change out ALL the fluid.



Joe

 

thanks joe ,but if i had a good looking assistant, i wouldnt be worried about the tranny. lol