jeepuser98

Just wanted to get a few opinions. I've got a 96 Cherokee automatic I'm not sure of the service history. I've got to change the trans coolant lines and was thinking about servicing the trans while I was at it. I've always heard mixed things about changing oil and filter on a trans that's either never had it or is way overdue. I'm at 195xxx miles. Anyone have any thoughts or experience with trans blowing up after service, or is this just a good ole wives tale.

jordan96xj

Its complicated, but not an old wives tale. A damaged transmission on it final legs can have problems brought to the surface by "flushing" out the existing fluid. But its not because of the fluid. Its because the transmission, and clutch friction material, has already been damaged by heat/abuse. Then the new fluid washes away any remaining clutch material that is floating around in there, and things begin to slip, possibly get even hotter, and so on.

You don't need to change the filter. It is simply a screen to keep large debris out.

You didn't mention the condition of your current fluid, before anything I would inspect the current fluid for color and smell to see if anything is alarming in that regard. If it was in good shape, I would give it 2-3 drain-and-fills over the next couple of weeks/months then revert to the normal operators handbook service intervals. If it was in marginal condition, I would probably do 2-3 drain-and-fills over the next few days and then resume regular intervals.

If the fluid is in terrible condition, then the decision is a little harder. That is where you have to decide whether to just leave it a lone, or do a series of drain and fills to get it back into good condition. Knowing that it could possibly bring potential problems to the surface. Ugh. Personally, I would do the drain-and-fills (there are some ways to do a low pressure complete flush as well, but someone else here will have to advise because I haven't done it). My reasoning would be that if I get the fluid condition back to where it should be I "might" have problems arise. But if I leave the terrible condition fluid in there...I am "guaranteed" to have problems...just a question of how long until that happens (my next camping trip? my next road trip with the kids on a hot summer hill climbing day?).

Ralph77

I have heard the same thing to. The grit and the gunk in there are what is holding the tranny together. Is it an old wives tale? Not a clue. Here is what I can tell you. Did a new gasket, filter, and fluid on both a '96 and '00 XJ. Because I wanted to. The pan was not leaking on either. The '96 had about 165K and I had no idea of the maintenance history. The '00 had about 148K and I know that the PO did do one at about 105K. Both trannys appeared to be fine before I did the maintenance. Both also seemed fine after. The '96 has been sold but still have the '00. With the '00 I have been dumping the tranny fluid with the drain plug every two years since. Couple tips. Disconnect the battery before you remove the tranny lines. You will be around the starter. You will need to buy the fuel line/AC line removal tool.

https://www.napaonline.com/en/p/SER774031

At the radiator side with the lower line I feel it is better to disconnect the line from the tranny with a Crow foot. Then clean out all the gunk that will be in there so you can use the disconnect tool above. I think I used a 19mm fuel line type crow foot.

https://www.napaonline.com/en/p/BK_7740126

If you drop the pan you might find that the dipstick tube will not come out. The upper part of the dipstick tube is in the lower part of the dipstick tube that is on the tranny pan with an O Ring. The O Ring gets hard and brittle. A little heat will help soften it up so you can separate them. I just brought both pieces to the auto parts store and found one that would work out of their assortment box. The part number is 53003977.