Before or after?

[jeepzj]

Should I drop the transmission pan to change the filter before or after I flush my transmission fluid(DIY pull cooler line method)? This is for a 1998 Jeep Grand Cherokee 6 cyl with a 42RE transmission. By the way, is the return line(carrying fluid back to the transmission) to the transmission the top or bottom fitting on the transmission cooler(it's integrated into the radiator)?

Thanks.

[ June 26, 2003, 07:57 AM: Message edited by: jeepzj ]

 

[Greaser]

Usually the line thats going OUT to the transmission cooler is the FIRST line coming out of the transmission...in other words the one thats in FRONT of the other...if I'm wrong you'll find out fast

...I would take off the line you choose (outgoing) and place the vehicle in NEUTRAL (wheels locked with parking brake & chocked)run it till about 3 quarts fill up a container (hose on end of transmission hardline)...stop it...put 3 fresh quarts in...put it thru all the gears...back and forth...then drop the pan and change out the filter and put fresh fluid in again...use the ATF+4 (don't cheap out here)...start it up...put in thru all the gears agian a couple of times...take it for a test drive to heat it up...check the fluid on level ground...don't overfill.

 

[jeepzj]

Thanks. That means the bottom fitting on my cooler is the return line back to the transmission.

You're procedure involves removing the pan twice. I plan on disconnecting the return line and attaching a clear plastic tube to it aimed in a bucket. Turn on the engine and place the transmission in Nuetral until I hear the line gurgle....that means the pan is about empty at which time I will shut off the engine immediately. Now I can remove the pan without spilling fluid all over the place and replace the filter and clean the pan. Then re-install the pan, fill with new fluid with the same quantity that came out. Start the engine, watch 2 qrts come out, turn off the engine and re-ill with 2 fresh qrts. Repeat this process until I notice the fluid in the clear plastic tube come out real clean. Re-connect the line, check the level and top off if necessay. How does that sound?

 

[jeepzj]

quote:

---

Originally posted by jeepzj:
Thanks. That means the bottom fitting on my cooler is the return line back to the transmission.

---

Check that. I meant that means the top fitting on my cooler is the return line back to the transmission....not the bottom line.

 

[Greaser]

Well..you can do it your way if you want...It's just the way I've always done it...getting 100% of the fluid out isn't needed...if you can get 80% out thats great...if you are unsure which line is which when you take off one put a clear plastic tube on both removed areas...one on the transmission line,the other on the rad nipple...put both in the bucket...this way there's no mess and it really doesn't make much difference anyway...have fun.

 

[unDummy]

Neutral and park are the same except that a parking pawl is engaged. Be safe and use park.

Drop the pan and replace filter before you flush.
If you remove the wrong line, you'll know which one not to touch the next time. I prefer flushing fresh ATF through the cooler, and I also use a clear hose purchased from homedepotplumbing. The clear line will "shoot ATFair slugs prior to gurgling--bubble pumping" and is great to watch the ATF change color and become clean.

Your method seems OK. But, I'd just dump in 5-6 quarts and run engine for a little longer. This gives you more time to shut off engine before running pump dry while monitoring the container filling, especially if you don't have an assistant to order around. This way you'll only need to run it twice to flush out 10-12 quarts and top off with ~4 more.
Plus, with the 2nd person monitoring the flow, you can slowly shift through all the gears during the 1st 5-6 quarts. You should have plenty of time before running out of fluid to move lever back into park and shut engine off.

Also, pumping out old fluid this way makes filter change less messy. Smart move!

 

[jeepzj]

quote:

---

Originally posted by unDummy:
Neutral and park are the same except that a parking pawl is engaged. Be safe and use park.

---

Actually, in Jeeps the transmission needs to be in Nuetral not Park. In Park the transmission pump does not move the fluid.

Thanks for all the replies. I will definitely drop the pan to change the filter before I flush. But first I will remove the line and let the transmission empty the pan so there's no mess when removing. Probably do it in 2 weeks so I'll post my results and comments then.

 

[Greaser]

Alot of Dodge vans used for commercial applications have burned transmissions due to operators running them in idle ..in park...NO fluid is being moved thru the cooler...sounds stupid...and it is...the only transmission made by D/C that doesn't need to be in neutral to get the fluid moving is the Jeep AW-4...with is made Ansin/Warner in Japan...a darn good transmission by the way...because Chrysler didn't make it

 

[dkcase]

quote:

---

in Jeeps the transmission needs to be in Nuetral not Park. In Park the transmission pump does not move the fluid.

---

quote:

---

Alot of Dodge vans used for commercial applications have burned transmissions due to operators running them in idle ..in park.

---

WOW ! ! Good information. I didn't know that. Thanks people....

 

[jeepzj]

Ok. Did some searching on the net and came across this pic of a transmission cooler line. Apparently from the website, they say this top fitting on a 98 ZJ V8 is the return line. This is the exact same line and fitting that's on my 98 I6. Question: when I unscrew the fitting from the cooler, does the thin metal line going into the fitting come out or is the line part of the fitting(the big nut looking thing)? Basically I want to be sure the clear plastic tube I buy to attach is the right size to fit over it.


Thanks!

Here's the site:
http://www.kevinsjeepparts.com/techarticles/zj-trannycooler.html

 

[Greaser]

I would unscrew thwe hose clamp from the fitting and pull off the line from there...usually a fitting is better off if you don't unscrew it...work with the rubber hose...it's almost the same set-up as my 99 XJ..except the lines are placed a bit different.

 

[jeepzj]

quote:

---

Originally posted by Greaser:
I would unscrew thwe hose clamp from the fitting and pull off the line from there...usually a fitting is better off if you don't unscrew it...work with the rubber hose...it's almost the same set-up as my 99 XJ..except the lines are placed a bit different.

---

I forgot to mention that the hose attached to the line in the pic is not the stock setup. The owner of that Jeep installed an auxilary cooler connecting the stock line to the auxilary cooler. So there is no rubber hose on the stock setup. So I have no choice but to disconnect the line right from the radiator.