Changing trans fluid and filter?????

New owner of a 99 Cherokee with 110,000 miles and a 4.0 liter. I would like to change my trans filter and fluid. Is there any tips or special tricks. I have not been under the Jeep yet and not sure what to expect. Is there a drain plug? Any special tools needed? Any cautions to be aware of? Also what type fluid do i need and is there any additives that should be used for a high milage trans? Will I need silicone to reseal the trans pan?

newjeepowner said:

New owner of a 99 Cherokee with 110,000 miles and a 4.0 liter. I would like to change my trans filter and fluid. Is there any tips or special tricks. I have not been under the Jeep yet and not sure what to expect. Is there a drain plug? Any special tools needed? Any cautions to be aware of? Also what type fluid do i need and is there any additives that should be used for a high milage trans? Will I need silicone to reseal the trans pan?

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Get your socket set out and find the right size for the drain plug. Drain into a catch pan and then take off the tranny pan. Take off the filter and replace with a new one. Clean all surfaces where the pan will seal up and clean the cover pan good.
Usually when you buy a new filter you get a new rubber gasket. I choose to use silicone. Apply a thin layer and let it cure for a couple of minutes. Put the pan up to the tranny and start putting in the bolts from middle out. Tighten down but not to tight. Just snug them up. You don't want to squeeze out the silicone.
I use dex/mer III or regular automatic transmission fluid.

Kim.

I found the write up on gojeep very helpful.

http://www.go.jeep-xj.info/

The drain plug is, I believe, either 10m/m or 12m/m. Expect the pan to retain a little fluid - probably a pint or so.

The sump filter can simply be cleaned by blasting out with carburettor cleaner - but remove it first. If you can't get a gasket for the thing (I think it only comes as a kit,) you can either cut one out of bulk gasket material, or "build" one out of RTV or Gasket Eliminator, if you're carebul.

The pan bolts should be 10m/m, but there are a couple dozen of them, so don't lose track. The rearmost ones are going to be a little difficult, with the crossmember in the way, which is why I'd advised you to drop the pan the first time, and then every third or fourth time after that (N.B. your original thread.)

I find it most useful to use a "spinner handle" or a nutdriver on the bolts when putting them back up. If you have a torque wrench that goes low enough, 84 pound-inches/7 pound-feet is PLENTY for the gasket. I use LocTite #222 to retain the bolts out of sheer habit - I don't like things working loose.

Scotch-Brite pads and carburettor cleaner will work neatly for cleaning up the mating surfaces - they're what I use on pretty much ALL gasket jobs.

5-90

You can get a gasket for the trans pan by itself at napa and other stores that stock a lot of parts. Hopefully the guy at the counter will know what youre talking about. I also have this razor blade-on-a-stick tool, its good for removing large chunks of gasket material.

Get a power flush, it's much better than just dropping the pan and changing part of the fluid.

Will my local Jeep dealer be able to do a flush?

newjeepowner said:

Will my local Jeep dealer be able to do a flush?

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I just did a flush.
I drained the pan, poured in about 3 Qts, disconnected the return line from my transmission cooler, stuck it in a 1 gallon graduated container started the engine and I started pouring in as it came out. When it got a little too far ahead of me, I turned the engine off, emptied the 1 gallon container back in the quart containers and repeated until I got about 12Qts out.
Then I reconnected the hose and with the engine running I put enough th wet the bottom 1/2" of the dipstick. I took it out for a ride and a dozen miles or so later put it back in the garage. It needed less than a pint to bring the level right in the middle where I like to keep it.
The fluid wasn't bad to start with, I've been doing partials for a while, right now it looks perfect. I used Valvoline MaxLife, I figured with 150K miles, it might need the additives they claim will keep the seals soft. I was planning to pull the pan off, and change the filter. I took the bolts off, and the cross member and dropped it far enough to see the bottom and the magnets. They looked great and the synthetic gasket looked good, so, I just put the pan up and bolted it. It was getting too hot to be anal about it.

But a power flush uses special solvents and back flushes all the crap and varnish out.
Cleans the filter, heat exchangers and valve body.

langer1 said:

But a power flush uses special solvents and back flushes all the crap and varnish out.
Cleans the filter, heat exchangers and valve body.

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Hmm. I got my tranny flushed at Fiffy Lube for $100 months ago, but I don't think they used anything more than dex III to flush it with. Where do you go to get such a complete flush?

My local Tranny shop did a flush and filter change for $90. They hooked it up to a gizmo that pumps (I think) mineral spirits through the system and then put new fluid in. Took about an hour or so.

I'd be interested in hearing more about the power/back flush. From all my previous reading, I had thought that the AW4 had an unnaturally high rate of failure after being power flushed, and that it was recommended to just change the fluid.

I have a '98 4.0 auto trans. and I took it to a trans shop to get it flushed and they told me the same thing I heard from others. Unless you have always had the vehicle and always did a regular flush then it would be fine to do the flush, but if you do not know how long it has been since it was last changed that it is best to simply replace the fluid and filter. They said that flushing it could actually hurt it. They did what the previous posts said to do. Drop the pan, clean all surfaces and change the filter.

lilredwagn said:

I'd be interested in hearing more about the power/back flush. From all my previous reading, I had thought that the AW4 had an unnaturally high rate of failure after being power flushed, and that it was recommended to just change the fluid.

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I got a '96 that keeps ticking like a Swiss clock. I don't let anybody touch it.
When I bought it 100K miles ago the fluid was dark and smelly. I almost didn't buy it because of that. Since then I did a lot of partial changes and installed a transmission cooler and she is working great. I have a problem with somebody pushing fluid backwards and using solvents.

I am scared to change the filter and partial fluid now. 2 other people outside this board said if it isn't broke don't change it. they claimed they knew 2 people that changed their fluid and filter and ended up with their trans going out in a day or two. They were not Jeep's. I have 110,000 miles and have no idea if it has been serviced before. the fluid is a golden brown. Not really smelly. This vehicle is going to be my only mode of transportation in a week and I don't have money to fix a trans. What should I do??????

As far as i am concerned that way of thinking is flawed and wrong. That would be like saying dont change your motor oil bc its a bit old. The old tranny fluid is brown bc it has lost many of its tranny needing properties. Lubrication and cooling are the main properties that a tranny needs to operate and live long. As long as you keep driving the auto tranny with worn fluid you are having it get hot and lack lube. While changing the fluid in cetain circumstances might hurt the tranny, you are putting yourself in a worse situation when it could fail when you last expect it to.

Do yourself a favor, go get a yourself a box of mercon/dexron III and a new filter kit. Should be less 40$ for both. Drain the fluid via the drain plug, slowly release the pan and finsih draining it , remove the filter, install the replacement clean the pan and reinstall with new gasket.

pete

Id do several drain and fills and leave the filter alone. Itll be about as good as a flush and remove most of the old fluid (by dillution). Drain/fill then drive it awhile. You wont get much fluid out just by doing the drain and fill once. My understanding is that the filters dont get clogged or pick up much crud in most cases. Several technicians have related the info about the filter to me.

I still recommend changing it out yourself. As already mentioned, go get a case or two of tranny fluid and a filter from your local parts store. Drain it from the drain plug and fill it. I would do it twice than the third time pull the pan, change filter, apply new gasket and put the pan back up.

Kim.

Here is another way of doing it.
Every time you change the engine oil, why not dump the transmission fluid also.
Drain it in a container and then measure it. I use a 1 gallon container marked in quarts. If you get 3qts out, install the drain plug and pour in 3 qts. If you want to play it safe and avoid overfilling, pour in 2 7/8 qts, drive it for 5-10 miles depending on outside temperature, check the level and add as needed.
If you do that every time you change the engine oil, you'll end up with clean fluid. If you can't wait that long, drain, fill, next weekend repeat.

thanks for all the info and suggestions. i will try falcons method for now.