xj00

So I have done quiet a bit of research on here about changing tranny fluid and Im still not convinced on what to do with confidence yet. Maybe I can get some input from someone close to my situation that has gone through with a change and has a good amount of miles on the change. Curious if there are people out there with 15 to 20k after a fluid change that have experienced no issues.

OK so heres the deal. I have a 00 with 160k. I got the jeep at 120 and it had been neglected. From the looks of the heater core it was sitting for some time.
I have the np231 and my fluid is DIRTY. I noticed that in the past 40k miles I have noticed a gradual loss of power. It ran like a banshee when I got it and now I feel like it is gradually getting slower and less responsive. I adjusted the tv cable and that helped a little but I feel like there is still power to be gained. If I do the pan drop or any of the other methods noted for fluid change, would I be at risk of slippage? I would be surprised if the tranny fluid has ever been changed from the looks of the color.

What would you guys suggest? should I keep the fluid and hold on to a dirty (probably going to fail) tranny or risk doing the frequent change until clean? I know there are many posts on this but curious what ppl think on my specific circumstances.

Thanks

tjwalker

Change the fluid. Fluids are the lifeblood of your vehicle.

Drain what is in the pan (3-4 quarts). Then drive for a while, then repeat the drain and fill until the fluid stays RED in color and does not smell BURNT.

Use Dex/Merc III compatible fluid. Don't use ATF+4, regardless of the Chrysler TSB stating it is the proper fluid. Some (not all) have had issues with ATF+4. Nobody has issues when sticking with Dex/Merc compatible.

And don't forget about all of the other fluids. Transfer case, differentials, cooling system. If the vehicle looks like it was neglected, it was.

XJJeff

The transmission and trasfercase both use DEX/MERC III fluid. For the transfercase you can change with any off the shelf brand, I change it every 12 months. Wont cost that much and you will also need a hand pump.

For the transmission that is tricky if it is how dirty you say it is. You have two options you could just drain, add fluid repeat. I personally use Valvoline Max Life DEX/MERC III transmission fluid. The second option depending on how much, see if any garages offer a gravity feed transmission fluid change. Not a flush, that uses pressure to force fluid out. Gravity is exactly how it sounds they run the machine down then shift through the gears then you add the new fluid.

xj00

What would be my best bet of the two. Is the shop option better and worth the money if it is bad. And yes it is very nasty. Black qnd grey. No red color whatsoever.

Or should I just try the replace repeat?

tjwalker

Either one; gravity feed or do it yourself. Just pick one and go.

XJJeff

I changed the fluid 3 times and replaced my trans-filter/gasket all together I spent around 80$, and I know I have the best transfluid for the money in there. What I said before I would get a price or you check to see if you have any chunks of metal in the transmission pan, either by draining it out or pulling the pan as I did. If you choose to pull the pan, I used this for my AW4 and for the fluid I used Volvline Max Life red bottle. You can pick it up in Walmart, or any chain auto part store a gallon for about 20$.
Its really hard to tell personally I would change the filter and fluid, unless you find metal then I would ask a professionals opinion.

Wix 58936 Automatic Transmission Filter Kit

RatchetMaster10

changing the transmission fluid after it is that bad is a 50/50 shot. either it will help the transmission performance or it could make the transmission performance worse and possibly ruin the transmission. i would start buy pulling the pan off and changing the filter and gasket, then putting it back together and just topping it off with good clean fluid. i have been a tech for 6 years now and have seen both cases where a trans fluid change has helped solve problems, and i have also seen cases where after a fluid change we are putting a transmission in a month down the road if not sooner. no real easy answer to give you. also is the transmission slipping? when you full throttle or accelerate heavy when at a low speed do the rpms scream and the vehicle speed stay pretty slow? if not then your power loss may be a issue not related to the transmission.

xj00

No slippage. But yes this is what I was afraid of. And yes it does scream when I punch it but just doesn't have the power it used to. Any thoughts?

RatchetMaster10

since its not slipping, then i would start to look at other potential problems. have you checked spark plugs to see what condition they are in? also do you have a check engine light on?

xj00

In the last 4 months
Plugs are new. No engine light. Replaced a number 3 injector a couple months ago. Tv cable adjusted. Cleaned the kn filter. New valve cover gasket. And new groment and plastic peics on top of the valve cover (pcv?) What could I be missing?

And it still runs really good. Just don't think it runs as banshee like as when I first got it. It used to have morw zip and power than my wifes xterra and now the tera is def more zippy

RatchetMaster10

alright, just gotta ask, what plugs did you put in it? jeeps only like champion. and there is so many things to check, i would start now checking fuel pressure at the rail make sure it is in spec. 44-54 psi at idle.

xj00

Champion copper pkugs. Il check out the fuel pressure. Would low pressuee be due ro a failing pump or a clogged filter?

RatchetMaster10

Sweet, good plug choice. And low pressure would be due to a failing pump or fuel filter. More than likely a pump. I have yet to see a filter clog enough to cause a running issue.

xj00

So I feel like the engine is running top. It just seems like in the transfer if power it is not harnessing as much of the engines power to the wheels as it used to. The enginw is still runin at the rpms it should. Just feels like the hing doesn't have as much response. Like you said. . .engine running great but not accelerating like it should

RatchetMaster10

and the engine may be running in top shape, but if the fuel pump is weak and cant keep up with the demand for more fuel when your driving then this will cause poor acceleartion