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So as I am learning more about the truck, more questions are coming up.

1. I have a 2010 Sport Hemi with Trailer Tow iv package, which as I understand is rated at 7200 lbs. How come the sticker on the door says not to exceed 1300 lbs of occupants and cargo?

2. QTII 4x4 system - no friction modifier needed in either axle when changing the fluids?

3. I got the build sheet for the truck and was surprised to see that the tow package did not come with a transmission cooler. How come? Doesnt say anything about an upgraded cooling system either? (does mention a power steering cooler though)

4. The cooling system in my Durango was very simple - a clutch fan attached to the water pump and an auxilary electric fan.HOw does the fan function here? It says to be working off the power steering fluid? Just trying to understand how that's possible and what the advantages are.

Thanks in advance.
 

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1. I have a 2010 Sport Hemi with Trailer Tow iv package, which as I understand is rated at 7200 lbs. How come the sticker on the door says not to exceed 1300 lbs of occupants and cargo?
7200 lbs is how much you can tow with it. 1300 lbs is how much you can carry in/on the vehicle itself.
 

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1. I have a 2010 Sport Hemi with Trailer Tow iv package, which as I understand is rated at 7200 lbs. How come the sticker on the door says not to exceed 1300 lbs of occupants and cargo?
Internal Cargo rating and TOW rating, they are different.

People that bought late 90's Ford Explorers, never checked those figures, if they did, the likely would never have bought them, the rating was so low (I think the internal cargo rating was like 750lbs or there abouts) you couldn't fill all the seats with adult men, you could carry normal sized passengers or some luggage, NOT both. Of course no one bothered to follow that, nor even figure it out, throw in bad firestone tires, underinflated (to mask the rough truck suspension) and NOT checked or topped off by the owners so the tire pressure went dangerously low with overloaded vehicles, and you got the fiasico that nearly ruined Ford and arguably did ruin Firestone, that is NOW just a subsidary of Bridgestone.

And we get to pay extra money and aggrevaition for the Federally Required TPMS system that you see so many posts complaining about. Because the Federal Government decided we all must be idiots like those couple Ford Explorer owners.

2. QTII 4x4 system - no friction modifier needed in either axle when changing the fluids?
I'd confirm it is QTII and NOT QDII, but yes, if they are open differentials there is NO need for the fricition modifier, and NOT only is it cheaper, if you don't need the friction modifier then the oil in the diff will arguably be a tiny bit better at lubing your diff. (NOTE, if you need friction modifier use it, clutch packs don't work right and wear out super fast without it).

3. I got the build sheet for the truck and was surprised to see that the tow package did not come with a transmission cooler. How come? Doesnt say anything about an upgraded cooling system either? (does mention a power steering cooler though)
I think, BUT DO NOT KNOW, that the Commander V8's come with heavy duty cooling as standard equipment. So the Tow Package does NOT need to add extra cooling. It appears the Tow Package is just the extra transmission modes and buttons for Tow Modes and I believe they beef up the rear suspension for tongue weight and handling with a Tow load.

4. The cooling system in my Durango was very simple - a clutch fan attached to the water pump and an auxilary electric fan.HOw does the fan function here? It says to be working off the power steering fluid? Just trying to understand how that's possible and what the advantages are.
This also surprised me, the first couple times I saw people post about the Power Steering Hydrualic Fan, I was replying they must be wrong and thinking of a Vicsous Clutch Fan.

I guess they have been using this on Pick-Ups for a couple of years now.

Electric Fans have a limit, you get to a high enough air flow, they just aren't efficient enough and get really expensive. Engine driven fans are never efficient, the Viscous/Hyrdaulic Clutch Fans improve that, but nearly as much as an electric.

I guess the Hemi is so crammed in and lacking so much space, they couldn't even fit an engine driven fan and an electric fan big enough to handle the load couldn't fit either, or was too expensive or just doesn't exist. So they used a hydrualic fan, and the PS system is a readily available hydraulic system, just tap off the hydrualic supply from that system.

The Commander has a new PS fluid spec, its only available from the dealer, and usually when the manufacturer uses and recommends a new kind of fluid for a system in their vehicle, it is because no other existing fluid can stand up under the demands of the new system. I "suspect" the Hydrualic Fan is the reason for the new PS fluid in the Commander, but I have NOT found anything to confirm or deny that, Jeep recommends the new fluid for all Commanders whether they have the hydrualic fan or NOT.

Take most of that with a grain of salt, most of it is what I see posted on the boards, some of that info may be wrong. Other please correct me where I'm wrong.
 

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Unbelievable post, Mongo. Thanks so much for going into all this detail. I am learning a ton here.
SO how does this power steering driven fan work? I mean electric fans turn on when the temperature reaches a certain number. The clutch fans slip more or less depending on how hot the fluid inside gets. How do our fans control the temperature?
And yeah, I checked the build sheet. It is a QT2 with 2 conventional axles. I really thought all hemis would have the QD2 system, but I guess not. At least I got the 3.73 gearing.
 

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Unbelievable post, Mongo. Thanks so much for going into all this detail. I am learning a ton here.
SO how does this power steering driven fan work? I mean electric fans turn on when the temperature reaches a certain number. The clutch fans slip more or less depending on how hot the fluid inside gets. How do our fans control the temperature?

Well, I think only the Hemi has an hydraulic fan, the V6 has an electric fan (as well as a smaller cooler system). The hydrualic fan has electric controlled valves in it (pretty sure, but not positive) and the PCM turns the hydraulic fan on and off by opening the valves to provide/cut-off hydrualic pressure from PS system.

NOT sure on what fans the 4.7L V8 has, I think its an engine driven fan with an auxilary electric to kick in and help when the low drag engine fan can't keep up under full load.

The clutch fan doesn't work like you're thinking. The hotter a fluid gets, the more viscous it gets and would allow more slip, NOT less. The real key to the viscous clutch fan is the thermal valve on the front of it, its a bi-metal spring connected to a valve, the warmer the air is that flows over the front of the viscous clutch, the more the bi-metal spring moves as it heats and thus moves the valve that controls the viscous fluid to make it slip less, NOT more. The air over the clutch gets cooler, it reacts to let the fan slip more and NOT suck away as much power from the motor.

Thats why the viscous clutches have such a funky big pie-plate face to them, they have to absorb the heat coming off the radiator to get them to change the amount of slip fast enough in reaction to the heat from the radiator.

And yeah, I checked the build sheet. It is a QT2 with 2 conventional axles. I really thought all hemis would have the QD2 system, but I guess not. At least I got the 3.73 gearing.
If it was me, I would just make doubly sure by physically confirming it, although I really doubt it would be different than the build sheet.

Do a search on the forum, there are several posts describing how to spot the differences, since the ELSD's are bigger than regular Diffs, the axle case has to be a little bigger, this results in them having extra bolts on the covers. NOT sure on the front, but the rear has 12 bolts instead of the normal 10 if you have an ELSD. I'd confirm that info, I'm going from memory.

You can also jack the car up and spin the wheels and see if they turn in opposite directions to confirm its an open diff. Since the ELSD can vary clutch friction, I'm NOT sure if they might NOT pass this test also, but I'd think they would have enough pre-load they wouldn't.

Although I'm sure the difference in protection is negligible if you do NOT use the friction modifier, arguably the fluid is more slipperly and better lubing, if you don't use it, even if only a tiny bit that doesn't make a difference. Really, it comes down to why spend $20 for the additive if you don't need it. If you have an ELSD, you'll burn up your clutches and it won't work right without the modifier, so no one get the impression NOT using friction modifier with an ELSD is a good idea, it isn't.
 

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And yeah, I checked the build sheet. It is a QT2 with 2 conventional axles. I really thought all hemis would have the QD2 system, but I guess not. At least I got the 3.73 gearing. [/QUOTE]

I believe that all QDII equipped Commanders have a little plaque on the shifter bezel that says "Quadradive II" as part of that option package. Welcome to the forum and I agree with you: this place rocks for learning about your Commander.
 

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I topped up a coupe times with Amsoil Power Steering Fluid (as recommended at their site for the Commander) and no troubles so far.
Yea, for myself, the fluid has got to meet or exceed the specific spec called for by the Manufacturer, unless I see solid evidence otherwise, I don't trust it.

The AMSOIL PS fluid does NOT list the MS-10838 as meeting or exceeding, so I don't use it. I go to the dealer and get the specific MS-10838.

I "suspect" the newer (and logically better) fluid is because of the Hydrualic Fan and if you don't have a Hydrualic Fan you don't need it, BUT, Chrysler does NOT recommend a different fluid for the NON-Hydrualic Fan Commanders, so I could be very wrong (and why I don't risk it myself, I use the Dealer fluid).

Although I have used AMSOIL to fill other systems, and do believe they do produce a superior fluid.

I'm taking a risk using their Synthetic ATF, it is NOT certified to meet ATF+4 specs and despite what they claim, they admitt in their FAQ that their Synthetic ATF does NOT meet every spec of ATF+4, or all the other fluids that have different specs, yet they claim it meets the spec for all of them.

AMSOIL's argument is that it meets or exceeds all specs, and the few specs that are a single specific number, its set at a center point between all the specs of the different fluids, where the slight difference won't be an appreciable effect and that their fluid will degrade much slower and stay closer to the spec than other fluids that will drop well below the spec during its life. i.e. it might NOT be the right viscosity when you first pour it in your trans, but in 10k miles it will be much closer to the spec viscosity than all the other fluids you use.

That plus some research into the history of Chrysler ATF+ versions*, several expert opinions and credible although antidotal attesting it works fine in ATF+4 applications, convinced me to try the AMSOIL Synthetic ATF and so far it seems good.

*After reading some history at the Allpar.com site, its seem pretty clear Chrysler keep improving their ATF+ spec because they had several problem trans that were cooking the fluid and producing a more durable fluid was more cost effective than coming up with a better trans. ATF+4 is the point where an oil company came up with a new technology additive package that stood up to way more abuse than the ones in the past and combined with Synthetic base stock, Chrysler finally had a fluid that actually kept those bad trans alive longer than the warranty, without a fluid change. (The A604/41TE in the Mini-Vans and some other vehicles).

Thus, its really NOT some magical formulation or some wild different specs of ATF+4 that makes it actually keep some of the problem trans alive, and the very valid warning that using any other fluid will garauntee death to the trans, its the fact the ATF+4 is many time more durable than other fluids is why its the only fluid for those problem trans.

The expert opinions and antidotal evidence also confirms this, the Redline, AMSOIL and Mobil1 Synthetic ATF's stating they can be used in ATF+4 applications are super durable fluids that will hold up in those ATF+4 applications, while other trans fluids are NOT. And that is the key behind the ATF+4 fluid and why the couple of oil company's claiming their fluid can be used for ATF+4 even though it doesn't exactly meet all the specs.
 

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And yeah, I checked the build sheet. It is a QT2 with 2 conventional axles. I really thought all hemis would have the QD2 system, but I guess not. At least I got the 3.73 gearing.
let the last 8 digits of VIN, will check tomorrow on the basis of Chrysler's completion and say that you should in bridges.
turns on in Russia easier if included in unit Limited, the QD2 is the standard ))))))
 
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