Bulletproof AW4?

[wescam]

Real quick guys, on a scale of 1 -10

1 being changing a tire
10 being ring and pinion swap

how hard is installing an aftermarket tranny cooler?

(seems like a good idea for just about any XJ owner)

I'm guessing about a 2 or 3 right?

 

[woody]

Running the fluid through the radiator after the cooler is probably a good idea.....never thought of it that way. I bypassed the radiator to help the engine cooling a little figuring it wouldn't hurt to isolate the small amount of heat from the trans. Luckily, our beloved XJ/MJ's have very durable motors and trannies. Allows for the $$ to be spent on other stuff......

I won't debate it, But I don't think I'll change either of mine back to running through the radiator either.

If the typical 4.0 cooling system were robust, it would be a non issue... OTOH I like how mine is cooling (the engine) now... with the ATF out of the rad...

What would be your ideas on safe parameters of AW4 transmission operating temperature vs coolant/engine operating temperature? I can take some (fairly accurate) readings in the morning... My DD seems 'overcool' and the remote tranny filter only barely gets hand-hot. OTOH no condensate evidence on the dipstick indicates the tranny isn't a dew-pit either.

 

[BigDawgz]

I read through this post and I never did see what gear ratio you were running with that big of a tire? I know that the snows that we get here around me....occasional 3'-5' drifts in the county next to mine. They don't really plow the outer reaches of the county and they only have one grader to work with for a very large, less-populated part of the county. We have to gear pretty low for a 38" tire, at least I would anyways. I'd think 4:88's at least. I think the lack of proper gearing is the number one cause of tranny problems with lifted, off-road rigs. I'm not assuming anything about your rig .... you could have 5:13's for all I know...but I was just wondering what you were running in yours. I'm just going on my own experience here.

Without the lower gears....snow, mud and/or sand can really kill the tranny. It bogs everything down so badly and causes the convertor to lock/unlock excessively ... and it causes alot of excess heat. I've seen lots of tranny's so hot that they boiled over and out the dipstick tubes. That can't be good on them....I always run a better cooler....but I've yet to have to do one on a AW4. My present lifted rig is a 5-speed, I have another stock one with an auto...but it doesn't apply to this. But I did have another XJ on 34" tires for a couple of years and it had an AW4 in it and I never had any problems with it either. It had 4:10's in it.
Just my thoughts on it,
Aron

 

[BrettM]

I read through this post and I never did see what gear ratio you were running with that big of a tire? I know that the snows that we get here around me....occasional 3'-5' drifts in the county next to mine. They don't really plow the outer reaches of the county and they only have one grader to work with for a very large, less-populated part of the county. We have to gear pretty low for a 38" tire, at least I would anyways. I'd think 4:88's at least. I think the lack of proper gearing is the number one cause of tranny problems with lifted, off-road rigs. I'm not assuming anything about your rig .... you could have 5:13's for all I know...but I was just wondering what you were running in yours. I'm just going on my own experience here.

Without the lower gears....snow, mud and/or sand can really kill the tranny. It bogs everything down so badly and causes the convertor to lock/unlock excessively ... and it causes alot of excess heat. I've seen lots of tranny's so hot that they boiled over and out the dipstick tubes. That can't be good on them....I always run a better cooler....but I've yet to have to do one on a AW4. My present lifted rig is a 5-speed, I have another stock one with an auto...but it doesn't apply to this. But I did have another XJ on 34" tires for a couple of years and it had an AW4 in it and I never had any problems with it either. It had 4:10's in it.
Just my thoughts on it,
Aron

he's got plenty of gearing, 5.38/5.43 and an Atlas if I remember right.

 

[SeanP]

he's got plenty of gearing, 5.38/5.43 and an Atlas if I remember right.

Dude, do you have a database on everybody? eStalker!!! :flipoff:

(thanks for posting proof of my running rig. Can you see my big shiat eating grin in that motion pic???)

I think that finding an old AW4 tranny pan and splicing two together would make a nice pan. Might have to incorporate that.

SeanP

 

[BrettM]

hey, I couldn't remember if you have the 4.3 or 3.8 Atlas! And remember, I've been under that XJ before and done some grinding, so it doesn't count as eStalking

splicing 2 pans together is a great idea, you've probably already seen GoJeep's writeup: http://go.jeep-xj.info/HowtoAutoDeepPan.htm

 

[BigDawgz]

he's got plenty of gearing, 5.38/5.43 and an Atlas if I remember right.

I'd say that gearing definitely isn't a problem for this XJ then. I'd just go with the cooler like everyone's saying. I think I'd rather give up the A/C condenser and the A/C....and be able to put any size cooler I wanted up front. If I ever switch over to an automatic....I'll probably run a BIG cooler and I've been thinking about doing the onboard air with the stock A/C compressor. If you do this mod....I wonder if you still need the A/C condenser?

I've commented on these AW4's before...I've got several buddies who work at a Jeep dealer about 30 miles from my house...and my best friend has been their #1 tranny man for quite a few years. He's always said that out of all the Jeep/Chrysler tranny's he's done.....the AW4 is the one that he's rarely/if ever had to rebuild. He's addressed some electronic issues with these...but hardly any mechanical problems. Could just be a coincidence...but I'd think that after 3, 4, 5....even 6 years....he surely would've had to do quite a few of these by now.....if they were problematic.
Aron

 

[houlster]

splicing 2 pans together is a great idea, you've probably already seen GoJeep's writeup: http://go.jeep-xj.info/HowtoAutoDeepPan.htm

I found his writeup when I was working on my driveline swap and ended up doing the same thing. Only thing I would like to add to it is lowering the oil pickup a little bit as well, but haven't taken the time to figure it out.

--Dan

 

[woody]

I'd say that gearing definitely isn't a problem for this XJ then. I'd just go with the cooler like everyone's saying. I think I'd rather give up the A/C condenser and the A/C....and be able to put any size cooler I wanted up front. If I ever switch over to an automatic....I'll probably run a BIG cooler and I've been thinking about doing the onboard air with the stock A/C compressor. If you do this mod....I wonder if you still need the A/C condenser?

I've commented on these AW4's before...I've got several buddies who work at a Jeep dealer about 30 miles from my house...and my best friend has been their #1 tranny man for quite a few years. He's always said that out of all the Jeep/Chrysler tranny's he's done.....the AW4 is the one that he's rarely/if ever had to rebuild. He's addressed some electronic issues with these...but hardly any mechanical problems. Could just be a coincidence...but I'd think that after 3, 4, 5....even 6 years....he surely would've had to do quite a few of these by now.....if they were problematic.
Aron

If you dedicate the A/C pump to on board air, then the condenser is just out there in the breeze. It has the capacity to be a great trans fluid cooler... if it's mud/bug-free and the cores not kinked up or leaking. :dunno:

AW4s are tough... the several beatings I put on mine maybe not as bad as the beatings you put on yours, :dunno: doesn't matter to me , mine are cool. :laugh3: Take the advice here and run with it... no one would fault you for trying to improve on it, but try to shy away from it and have it burn ya and it's on Hope it isn't me that pulls ya out of the woods as I will :laugh3: :wave: while I call ya funny names for doubting experience...BUT I'd expect if my junk tranny's up in the next while I'll eat crow too. Fair's Fair. But the AW4 IS tough.
.

 

[Goatman]

If you did that you'd just have a better likelyhood of putting a rock through the tranny pan. Put on a big cooler, change the fluid every few years, and don't worry about it. Worry about wheeling it more often........

For the other guy, I'm running 5:13's and I got my tranny hot pushing through deep snow with 37's.

 

[JJacobs]

Filter appears to be a Champ TF209 from AutoZone. $19.99. I've fixed a few odd AW4 problems by swapping them out. Screen, filter, whatever, for the price it's not worth trying to clean it.

 

[woody]

I bet Goat had oil cavitation in the diffs too.... I've heard snow does that to people who still run differentials.

 

[Goatman]

Filter appears to be a Champ TF209 from AutoZone. $19.99. I've fixed a few odd AW4 problems by swapping them out. Screen, filter, whatever, for the price it's not worth trying to clean it.

Mine's done every two years.....drop the pan and clean the screen and magnet, so it never gets that dirty.

 

[woody]

What would be your ideas on safe parameters of AW4 transmission operating temperature vs coolant/engine operating temperature? I can take some (fairly accurate) readings in the morning... My DD seems 'overcool' and the remote tranny filter only barely gets hand-hot. OTOH no condensate evidence on the dipstick indicates the tranny isn't a dew-pit either.

As promised... some temp readings (taken idling in the shade, 75*f outside temp, using a Raytek IR laser thermometer) after 20 min. or so of "stop & go" urban driving...

Tranny pan: 143-145*f
Tranny filter housing/hose fittings: 100-105*f
Tranny cooler: 95*f

Head @ thermostat housing: 195*f
Head in back @ temp sensor: 225*f
Factory temp gauge reading: 190*f apprx.

Front exhaust pipe: 500+-*f :dunno: if our laser gizzy likes higher temps like that, the 538*C kiln we use freaks it out

Engine oil filter: 155*f

Notes: 88 4.0/AW4, has a 8 month old 2 core radiator, using 50/50 mix + 16oz WaterWetter & 'recent' NAPA water pump, Mopar 195* T-stat; Large (24kGVW) tranny cooler, Summit remote filter kit, fresh Advance Auto "house-brand" Dex-Merc III ATF

HTH, YMMV and all that.