projectXJ: 97-01 Jeep XJ AW4 transmission cooler lines full OE repair, the right (wrong?) way
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- Опубліковано 6 лют 2025
- Today on Workshop Quick Takes (wqt): If you have a 97-01 Jeep Cherokee XJ with the AW4 automatic transmission, you might encounter the badly flawed routing design for the unit's cooling lines. A worn or abused OE suspension can crush and damage the lines at the front axle pass-over.
Join us underneath our 2000 Jeep Cherokee XJ as we show you how to find the problem, locate the replacement hardware, and perform a complete swap to bring the vehicle back to OEM specifications. But is this the right way to get a permanent fix? Next episode, we'll explore the alternate (wrong) ways of addressing this problem, and maybe we'll discover the right way after all.
Part 2, the soft-line method: • projectXJ: 97-01 Jeep ...
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Parts & Materials List:
NAPA # 730-4978 (fitting, quick-disc., AW4 front or rear)
NAPA # 827-5285 (line, 2-part, I/L quick-disc. to rad. upper)
NAPA # 827-5297 (line, 2-part, I/L quick-disc. to AW4 rear)
NAPA # 872-5298 (line, complete, rad. lower disc. to AW4 front)
AGS "Sil-Glyde" silicone-based lubricant
Brake cleaner spray (any standard type or brand)
Hydraulic quick-disconnect tools (any parts store)
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Additional sound effects courtesy of Freesound.org.
This production may contain tips, tricks, and techniques that are unsafe for your application or flat out illegal to replicate in your country of residence. Use this information at your own risk.
Awesome video, packed with all the info 👍
XJ is so sooo clean , where's the rust where's the mud 😅, don't worry , my jeeps got you covered , and me
Colorado vehicle, born and raised, and the registration history shows Front Range counties only, no previous mountain homes. So, mag-chlor only. We have a substantial classic car community in the Denver metro for the same reason.
Excellent tutorial kind Sir.
Thank You.
I couldn't find any other videos showing this, thank you so much.
Glad it helped! Check out the second video if you want to see how to do it with soft line and clamps. I had unresolved suspension issues that ruined my first OE-style repair.
Thank you for this video. I am currently working on a 2000 jeep cherokee sport 2 wheel drive. And I'm working on the lower transmission cooler line. (which is the one that goes into the line that goes to the top of the radiator.) I was trying to figure out how to separate those 2 and you highlighted just that. This video was of great help and I greatly appreciate it. 🙏
Glad it was useful! If you want to try a soft line repair, check out what happened to my OE fix in Part 2, and the changes made.
@@aaronvienot yes sir. Thank you.
The rear area where you said looked like the pervious owner had a little fun is factory clearance for the sway bar. Every jeep ive worked on and seen has had it and the same as the crushed exhaust manifold down pipe to clearance the drive shaft.
I began to suspect that later after studying the geometry. However I also had the usual sagged rear springs when I first got this, and it looked like the sway bar had contacted that clearance gap a couple times and distended it further. The bottom of this XJ was also packed with mud, so......
Very helpful video man! You rock! This channel deserves a subs guys!
I drain the rad and remove that lower hose. Then it's easy-peasy to get the tool in there for the cooler line disco. And you don't have to ruin your disco tool.
On a side note, a lift has bonuses way beyond gouging your transmission fluid lines !
Great vid. About to replace my transmission line
You’re a beast man gonna do this myself
I have a factory service manual for a 1998 Cherokee. The diagram there shows the flow going into the top of the radiator and out the bottom. I similarly see a lot of dispute in diagrams posted online, with some showing the flow going into the bottom and others showing it going into the top.
I suspect the factory manual is correct inasmuch as the top of the radiator has a compression fitting, whereas the bottom is a quick-disconnect. The input line should be higher pressure, warranting the compression fitting.
My understanding from the factory text is that the radiator is used to warm the fluid, not cool it. This makes sense inasmuch as a 210F engine cooling system is too hot to cool transmission fluid. 210F is the high end of temperature for a transmission. And if the intent were to cool the fluid using a 210F cooling system then the fluid would have to be much warmer than 210F when it leaves the transmission. If your transmission is much north of 210F when it goes into the radiator, then your transmission's life will be significantly shortened.
If you live in an area without much of a winter, where you don't need to worry about the transmission operating sluggishly from overly thick fluid at sub-freezing temperatures, you might consider bypassing the radiator entirely. Given that XJ's tend to have trouble keeping cool, this will avoid putting more heat into the radiator.
Conversely, if there is doubt about the direction of flow you'd have to disconnect from the radiator entirely, and put each line in a separate container, then start the engine and see which one fills.
The "operating temperature" is not uniform throughout the coolant jacket. It can't be, because the coolant must absorb heat inside the engine and then lose it in the radiator. The "operating temperature" is the peak temperature, measured by the PCM at the thermostat housing. The coolant temperature then drops across the radiator due to heat removal by airflow, and rises as it moves back up through the engine. The driver's side of the radiator is cooler, and that is why the transmission cooling loop must run through that side even though the plumbing is longer. The fittings are typical Jeep mix-and-match; remember that both lines only use O-rings and plastic retainer clips at the transmission. The lines for the cooling loop are roughly at the same pressure, other than friction losses, because the loop is not doing work (unlike an air conditioning or power steering system). The OE aux cooler, if you have an XJ with the trailer towing package, intercepts the return line in order to remove additional heat before the final return to the transmission rear port. That's why it's got that two-piece line when the feed is just a single assembly. Also, if you watch someone disassemble an AW4 for rebuild, you will see an anti-drainback valve on the forward feed port. That way the AW4 doesn't have to completely refill the feed line and radiator loop each time the vehicle starts. I can't speak for all drivetrain combinations Jeep ever released, but that's how the 4.0/AW4 works to the best of my knowledge.
@aaronvienot I have a couple of old aw4s from past jeeps still in the garage. I may take one apart and replace the clutches and bands to have a spare for my son's Jeep. If so I'll look. From memory I recall that the Neutral safety switch is installed over the parking pawl there. I've rebuilt them before with varying degrees of success (one only lasted 40k). It's not as easy as th350, but not really hard to rebuild. It's just that any DIY garage-rebuild isn't going to be as clean as a dedicated facility.
The tow package was a dealer installed option, which is why it is in the factory service manual, and why the manual shows the flow direction. The reason why I did not authoritatively state it as being the reverse of what you showed is because it is entirely possible that it varies by model year. If you like I will send you a photo of the page and operation description from the factory. I discount the explanation of flow direction due to bubbles 100%. No matter which way the fluid flows the only exit for gases is the vent tube on the transmission body or the dip stick. Air has to be pushed back to the trans regardless. There is no exit at the radiator. And the tubes follow essentially the same route. Not sure what else to say other than what the factory said...but again it may vary by year. And I don't have the full factory set for all years, but only certain years in the past, and only 1998 now.
Fantastic tutorial. Thanks!
Great tutorial!
Thanks! Had to learn this the hard way, as the upcoming part 2 will show.
Great presentation thanks
My 01 cherokee has an Auxillary cooler.. so would the feed go into the auxillary cooler, return out and into the main radiator.. and then finally returning out of main rad and back to transmission?
@@brandontaylor-usedon3114 in scouting forums and the FSM diagrams, I've seen setups showing it both ways, and Chrysler did change up a few things like this depending on the year. Chase yours by following the front AW4 port up and through the line and see if it goes to the aux cooler first, or the radiator inlet, and that should prove how yours is configured.
@ the feed does go straight into the aux cooler! And when it returns. I can’t quite track it.. and it definitely doesn’t return straight back to the return to the transmission.. so my only guess is the main rad is the middle man between that return from the auxiliary cooler and the return that I find going back to my transmission
@brandontaylor-usedon3114 right, the theory in routing it through the radiator secondarily is that it will stabilize the output temperature of the cooled fluid so the transmission doesn't get over-cooled. Not an issue for desert climates but can be for those of us with cooler seasons.
Great video
Are the plastic retainers on the 800-714 the same as the fuel line retainers? Or there is any difference?
I'm not familiar with the Jeep fuel system as I've never pulled any components, but the quick-clip connector on the fuel injection rail has a visible smaller diameter than the transmission cooler lines so I wouldn't count on them being the same.
It is not the same, I bought a conector replacement from NAPA . I made the comparison and aren't the same. There are slightly equal but not the same. NAPA part no. 730-4978. Thanks
It was very helpful thank you very much....
Was this makes the thing stink
What kind of fluid came of it
All fluid lost during this video was ATF (Automatic Transmission Fluid) from the cooler lines and fittings. The spec for the replacement fluid was described around 08:55 or so.