1989 Transmission Fluid Change

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Kayparkah73
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1989 Transmission Fluid Change

Post by Kayparkah73 »

Hey guys, I have a 1989 Grand Wagoneer automatic, and want to change the transmission fluid and filter. It has about 130k on it.

Reasons for wanting to change is because it seems like it lags when shifting while driving. It doesn’t buck at any point when shifting, or changing to D, R, N etc. from what I read everyone says to start with a fresh fluid change, and filter.

I’ll be doing this in the spring, but do you have any advice when I change it or anything I should know?

Thank you! :fsj:

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1989 Transmission Fluid Change

Post by sirrus »

Get a new pan with drain plug factory one doesn’t have a drain and you have to take it off to change fluid/filter. It can be done without creating a royal mess or enjoying ATF shower, but if you plan to change the fluid again in the future I’d get a pan with a plug or put a plug in your current one.

Get a good gasket, I used Lube Locker and I like it a lot (also used their gaskets in both diffs). Some people prefer RTV, but I’d only use it if I couldn’t get the correct gasket.

Another thing to check while you’re in there is band adjustment, as they wear they might need some tightening. TSM should have a description of the procedure, it’s not difficult. If I remember right, you’ll need a square socket to turn those adjustment bolts
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riozilla
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Re: 1989 Transmission Fluid Change

Post by riozilla »

It’s fairly easy to do.

https://www.bjsoffroad.com/Torqueflight ... _1524.html

I like this gasket below the best:

https://www.bjsoffroad.com/LubeLocker-T ... _1823.html

Undo all of the fasteners and let her drain/drip out for a long while.

Install the new filter/pan cover and gasket. Put all fasteners back in. I can’t remember the torque settings for those but look it up in service manual or Google it.

Fill up transmission with the required amount of ATF via the filler tube that is near the back of the firewall at rear of engine bay accessible from the passenger side of the bay.

Topic author
Kayparkah73
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Re: 1989 Transmission Fluid Change

Post by Kayparkah73 »

Thank you so much for the info and advice. Our 89 is in better condition to become a summer cruiser than my 73, so I’ll be trying to get it going this spring. The transmission is obviously my big concern at this time, so hoping this fluid/filter change will help seeing as I have no idea when it was last serviced.

I’ll keep this post updated once it’s spring time as well.
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Stuka
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Re: 1989 Transmission Fluid Change

Post by Stuka »

The method mentioned above will only change half the fluid. To fully change the fluid you have to get the other half out of the torque converter, which is typically done with a flushing machine.

So people dont like flushing an old transmission as it can break loose buildup inside if it has never been done before.

But from what you are describing, you may just need a filter change, so a full fluid change may not be required.
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Kayparkah73
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Re: 1989 Transmission Fluid Change

Post by Kayparkah73 »

Thanks for the reply guys! Very much appreciated. I did find the build sheet for my Jeep, and it was pretty cool to look at. Looking at the build sheet though, it shows the transmission as, “8-Speed Automatic 8F27 Transmission”.

I know they came with a 727 or a 904, so seeing this is a little confusing for me. I want to assume it’s the 727, but not sure. Do you guys know which transmission this is, and much about it? Reading about it it seems like this transmission is just like the 360 that’s sitting in front of it, bullet proof.
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Stuka
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Re: 1989 Transmission Fluid Change

Post by Stuka »

Kayparkah73 wrote: Sun Feb 28, 2021 5:08 pm Thanks for the reply guys! Very much appreciated. I did find the build sheet for my Jeep, and it was pretty cool to look at. Looking at the build sheet though, it shows the transmission as, “8-Speed Automatic 8F27 Transmission”.

I know they came with a 727 or a 904, so seeing this is a little confusing for me. I want to assume it’s the 727, but not sure. Do you guys know which transmission this is, and much about it? Reading about it it seems like this transmission is just like the 360 that’s sitting in front of it, bullet proof.
What decoder did you use? Sounds like you were decoding for a current generation Grand Cherokee, which uses the 8F27.

The 904 only came behind the 258. If you have an 80+ 360, its a 727. There was two versions of the 727, one with a lockup torque converter and one with a standard torque converter.
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Kayparkah73
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Re: 1989 Transmission Fluid Change

Post by Kayparkah73 »

es, looking at this transmission I noticed that and thought it was odd. I found this on the build sheet, and this is the only transmission related item on there. Here’s the link for the build sheet, https://www.jeep.com/webselfservice/Bui ... 70KP107545

With the info you just have me, I’m going to say I have a 727 because I do have the 360 motor in this Jeep.
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Stuka
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Re: 1989 Transmission Fluid Change

Post by Stuka »

Kayparkah73 wrote: Mon Mar 01, 2021 8:15 am es, looking at this transmission I noticed that and thought it was odd. I found this on the build sheet, and this is the only transmission related item on there. Here’s the link for the build sheet, https://www.jeep.com/webselfservice/Bui ... 70KP107545

With the info you just have me, I’m going to say I have a 727 because I do have the 360 motor in this Jeep.
Ahh, Jeeps vin decoder for older vehicles is very hit and miss. I tend to use the one at oljeep, even though it is a bit more work:

https://oljeep.com/gw/vin-index.html
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candymancan
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Re: 1989 Transmission Fluid Change

Post by candymancan »

Stuka wrote: Sat Feb 13, 2021 1:16 pm The method mentioned above will only change half the fluid. To fully change the fluid you have to get the other half out of the torque converter, which is typically done with a flushing machine.

So people dont like flushing an old transmission as it can break loose buildup inside if it has never been done before.

But from what you are describing, you may just need a filter change, so a full fluid change may not be required.
I just fill it back up. Disconnect the cooling line and fill up a 1 gallong jug shifting gear. Then refill another 4 quarts. Do it again and refill to full and test drive to get it hot and make sure the level is right.

You can get most out this way
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1990 Jeep Grand Wagoneer 155k
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Kayparkah73
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Re: 1989 Transmission Fluid Change

Post by Kayparkah73 »

I have tried using the oljeep.com vin decor before, and the vin doesn’t seem to match up after the first 2 letters. But seeing as I have a 360, I’m gonna go with that I have the 727, just not sure which torque converter set up.
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dodgerammit
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Re: 1989 Transmission Fluid Change

Post by dodgerammit »

Kayparkah73 wrote: Tue Mar 02, 2021 3:35 pm I have tried using the oljeep.com vin decor before, and the vin doesn’t seem to match up after the first 2 letters. But seeing as I have a 360, I’m gonna go with that I have the 727, just not sure which torque converter set up.
You'll have the 727. My money is on non-lockup TC. Lockups were used in the very early 80s from what I've seen others have stated when they've pulled their transmissions for rebuild, etc. They seemed to have had issues with the lockup feature not working over time, hence many think to save headaches, they just opted to go non-lockup from then on. My 84 is a non lockup.

If you ever have it pulled, it's really easy to tell. If the input shaft is splined all the way to the end, it's non-lockup If the splines stop about 5/8-3/4" from the end of the shaft, it'll be lockup.

I believe there is another way to tell from inside the pan. Hopefully someone more knowledgeable in that dept will chime in.
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Re: 1989 Transmission Fluid Change

Post by tgreese »

Kayparkah73 wrote: Tue Mar 02, 2021 3:35 pm I have tried using the oljeep.com vin decor before, and the vin doesn’t seem to match up after the first 2 letters. But seeing as I have a 360, I’m gonna go with that I have the 727, just not sure which torque converter set up.
My quick examination of that decoder found some significant mistakes, at least in the 70s. Ideally you should look at the TSM for your year for VIN decoding. Most owners that do their own work buy their own copy.

https://www.bjsoffroad.com/1989-Jeep-Fa ... _1059.html
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candymancan
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Re: 1989 Transmission Fluid Change

Post by candymancan »

I dont think any wagoneers had a lockup convertor.. If you did youd notice a drop in rpms after 3rd gear. Easy way to see if you do is hit the brake pedal when your foot is in the gas. If rpms dont change. There is no lockup. At least this works on my ZJ. But it is electronic so i dunno.

But i still would think with lockup rpms would drop after 3rd gear.. itll feel like another gear shift
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1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
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Re: 1989 Transmission Fluid Change

Post by dodgerammit »

84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

92 Wrangler Islander 4.0/32RH/231 D30/D35 RHD

candymancan
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Re: 1989 Transmission Fluid Change

Post by candymancan »

Interesting. So how would you know you had it without looking at the shafts or re uilding. I certainly dont feel an rpm drop or see it on my tach after 3rd gear so i dont think i have a lockup convertor but who knows
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)

89_Wagon
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Re: 1989 Transmission Fluid Change

Post by 89_Wagon »

I have an 89 as well. There's no lockup converter... Just a normal 3 speed. Also, if you're adjusting the band's, be aware the TSM neglects to mention after torquing the adjustment screw to back them out. I forget the number of turns. I recall their being 2 screws and the TSM not mentioning to back out the screw on the first/reverse band.

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Topic author
Kayparkah73
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Re: 1989 Transmission Fluid Change

Post by Kayparkah73 »

Hey everyone! So update on the transmission fluid change.

The transmission gasket was leaking pretty bad, so I only replaced the gasket, clean up the pan, and put new oil in it. It shifts fine now. Not exactly sure what was causing the shifting problem, but putting fresh fluid at least fixed it.

Thanks again for all the help!

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Re: 1989 Transmission Fluid Change

Post by rocklaurence »

Good to hear and maybe add a bottle of Lucas shift improver/cleaner

Topic author
Kayparkah73
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Re: 1989 Transmission Fluid Change

Post by Kayparkah73 »

rocklaurence wrote: Sat May 22, 2021 7:59 am Good to hear and maybe add a bottle of Lucas shift improver/cleaner
Thanks for the advise! I’ll have to grab some
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