Possible consequences of not changing your tranny fluid?

[GasSavers_rGS]

Originally Posted by Red

What generation of Grand is it? From what I've heard from my friends with the 1 gen Grand (ZJ) most auto don't make it to the 100k mark without needing a rebuild. And thats just normal usage. The 2nd gens (WJ) are apparently better.

If it uses the original Chrysler 7176 tranny fluid, you don't want to do anything to it in my experience. Even a filter change. For some reason using any fluid other than 7176 destroys the torque converter and taking the tranny along with it. I haven't had any problems flushing trannys that use ATF+3/4 but YMMV.

Red,

From what I know, it's a 1997 model.

Questions:

1. How do I find/figure out if it's a ZJ or WJ?
2. What about a tranny fluid exchange performed at a Chrysler/Dodge/Jeep dealership? Would they already be aware of the potential issues and exchange the fluid properly?
3. What is the tranny fluid replacement cycle?

[GasSavers_Red]

Originally Posted by rGS

Red,

From what I know, it's a 1997 model.

Questions:

1. How do I find/figure out if it's a ZJ or WJ?
2. What about a tranny fluid exchange performed at a Chrysler/Dodge/Jeep dealership? Would they already be aware of the potential issues and exchange the fluid properly?
3. What is the tranny fluid replacement cycle?

1) Zjs were built from 93-98, WJs from 99-04. So you have a ZJ
2) They might have a clue. I doubt it though. Most likely than not, they would do a flush then refill it with ATF+4 or Dexron since those two are supposed to supered 7176, which in reality causes more harm than good. The catch is not the fluid, rather that the tranny has basically become accustomed to its current state of affairs and a change could damage it.
3)As Raccoonjoe said, its about every 40k roughly.

Depending on how the tranny currently is behaving you could either get years of service out of it or you may have to replace it. Driving it would get you a good idea whether or not you should factor the cost of a new tranny

[smay665949]

I agree with your theory; however, if you change the fluid and the tranny messes up it was just a matter of time before it would fail anyway.

[Gary Palmer]

I would vote in favor of leave it alone, don't change the tranny fluid. My brother has a Chrysler Town & Country that was at 140,000 and he was planning on having it changed. The transmission shop he took it to told him to leave it alone. They said that after it gets that far along, if you leave it alone, it will continue to run for a long while, if you flush and change it, it will go out within 5,000 miles.

He's at 180,000 miles and he still hasn't had to have the tranny rebuilt. It sounds counter intuitive, but I'd go with what works, not what apparently accelerates the problems. Worst case, you'll end up having to get it rebuilt, which is what experience seems to suggest will happen, just sooner, if you flush and change it.

[VetteOwner]

Originally Posted by Raccoonjoe

Factory interval for a Jeep Grand is somewhere between 30K and 50K (like most auto trannies)

A major word of caution!! If there are no records of tranny maintenance, DO NOT take the Grand to get a tranny flush/treatment. I don't know what it is about those transmissions...but they do not like it. (case in point....have a friend with 98 Grand. He flushed the tranny, added 1/2 quart Lucas ATF. 2 days later, he lost 1st gear and reverse. Now, new tranny time!!)

In my 89 Jeep Cherokee, I've not changed the fluid since I got it....and I'm reasonably sure it hasn't been changed in the past......2-5 years. The fluid is still in good shape, and hasn't been burned or scorched. I'm just going to leave it in there for the time being. When I do go to do maintenance, I'm just going to replace the tranny filter, then will *probably* put the old fluid back into the tranny, if it's still in good shape.

There should be zero concern that the transmission won't shift back into D at a light. If the owner needs proof, try it in a parking lot. Just make sure that they keep their foot off the skinny pedal, as throttle input will shock-load the TC, and possibly shorten the life of the drivetrain.

(and your worst case scenario?? It depends on how spectacular the tranny failure is.....I suppose it could damage the t-case (if equipped with 4WD), as well as engine damage (not likely at all, but possible) If the tranny locks up at highway speed, there's a big problem. Could throw a driveshaft, which is pretty cool to see from a distance, but incredibly dangerous/scary to see in person.)

no dont ever reuse old fluid...would you reuse your engine oil?

the reason why his tranny prolyl died is because a flush forces cleaner thru allt he little openings, prolyl removeing vital leak preventing gunk. just drop the pan, change the filter, new gasket and bolt it up and refill.

[trebuchet03]

I too say leave it alone, bring it to an indy shop...

Here's my abridged horror story with the dreaded ford CD4E slushbox (found in Mazda 626 2.0, ford probe 2.0, and a few other vehicles).

A few weeks after changing the fluid (right after buying - I used the "bucket method"), the Torque converter clutch started slipping. Eventually (within days) it got really bad and turned good fluid sparkley like with clutch material :/ That's when the transmission problem light came on.... Pretty much screwed over the underwhelming valve body. It required a rebuild ($2,000 - negotiated down from $2750).

What's bad about tranny fluid -- old tranny fluid... Over time or in times of high heat, it looses it's lubrication properties (aka "burnt fluid") and wear particulate goes up. So you're loosing lubrication while increasing grit. So you're wearing down friction material (clutch components, shift bands, etc.) and these components now depend on the less than slippery fluid conditions to keep hold. Take that away - and your components can't cope with the new loads and pretty much go into a high wear condition and eat themselves alive :/

In my case, the CD4E doesn't even have an external filter (just a 200 micron screen inside that require partial tranny disassembly to get at)! So given the small port sizes on that valve body.... It was a matter of time before something went sour :/


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So, to reiterate... Don't change any fluids - bring to an indy shop. It shouldn't be a problem with any other systems. Oh, but make sure your coolant is topped off as it would appear many cars are using tranny heat exchangers located inside the radiator. If you coolant is low, the engine may run fine - but the tranny is running hotter :/

[Danronian]

I agree, don't change it. I have had bad things happen after changing the fluid in a long neglected auto tranny.

[rh77]

Originally Posted by Danronian

I agree, don't change it. I have had bad things happen after changing the fluid in a long neglected auto tranny.

I've heard the same. It's been quoted as the "last nail in the coffin" for a failing automatic...

RH77

[GasSavers_Dust]

I had a Nissan March that I picked up with about 120K miles on it. Fluid was dark, so I changed it. Good for a day, then it started banging into 2nd. Changed it again, got worse. Put the original I had left back in, the bang wasn't as painful. Junked it after about 2 months.