Jeep Commander Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
36 Posts
Discussion Starter #1
I got my build sheet. What is a 300mm rear axle (200mm front)? My JK has a Dana 44, lots of info on that out there. I try to search for the XK rear axle and there isn't much info out there.

Is it any good?

3.73 ratio isn't too bad.

Looks like I have QT-II, which should be just great for my needs though QD-II would have been nice.

How is the transmission cooler on these (I do have the tow package)? I know on my JK the cooler wasn't too good and it was wise to add a bigger one. Is that needed here, I do tow about 3500lbs once a month or so?
 

·
Super Moderator
Joined
·
14,914 Posts
You can tow 3500 lbs with no problem. Your Commander is rated to tow twice that amount.
 

·
Super Moderator
Joined
·
14,914 Posts
Your build sheet says you have a 300mm rear axle ?
 

·
Registered
Joined
·
36 Posts
Discussion Starter #4
It says 200mm front and 300mm rear axle. I can't find any Google reference to it. What rear end is normal?
 

·
Registered
Joined
·
36 Posts
Discussion Starter #5
DJAS 200MM Front Axle DMES 3.73 Rear Axle Ratio DRSS 300MM Rear Axle DS7S Conventional Differential Frt Axle DS8S Conventional Differential Rear Axle

Here is the text from the build sheet. Does this mean anything to anyone? What are these axles/differentials.
 

·
Registered
Joined
·
36 Posts
Discussion Starter #6
So, I found some reference to the 300mm and it is used on the grand Cherokee that doesn't have a solid rear axle. So, my build sheet is messed up.

What axle do I most likely have? It has 10 bolts.
 

·
Registered
Joined
·
88 Posts
We share the same chasis as the GC, exact same. We have the chrysler 8.25 rear axle. You have QTII so you have a 10bolt diff, where as on mine QDII I have a 12 bolt to accomodate the actuator inside the diff to lock it. We all have the same axle
 

·
Registered
Joined
·
36 Posts
Discussion Starter #8
I know the 8.25 is pretty decent axle, my cherokee had one but I guess I am a little surprised it is stout enough for the hemi. It must be tougher than I thought, although most XK's don't have really big tires. From what I know about the 8.25 its good up through 35's and most running 37's are okay.

I am really impressed with how smooth yet rugged the XK is.
 

·
Registered
Joined
·
88 Posts
Unless you have a superlift you cant run larger than 32s and then 34s maybe 35s would fit.. Im not sure how the 8.25 works with larger tires, but does great with me 31.5s. You wont believe how capable these xks are. If you plan on wheeling at all get a lift and aggressive tires and hang on!!!
 

·
Registered
Joined
·
36 Posts
Discussion Starter #10
I won't be wheeling too hard, at least not right now. I have a nice 4dr wrangler for that. I have just been wanting to get rid of my old ram truck but still have something to pull the trailer and fit all the kids. We will do some exploring when we go camping so it will see some dirt roads and minor offroading but the rockcrawling will be reserved for the JK.

Just got to get this XK figured out, there are more buttons on the steering wheel than in my entire JK.
 

·
Super Moderator
Joined
·
14,914 Posts

·
Premium Member
Joined
·
6,309 Posts
Our rear axles are very simailar to a "full floating" rear axle. Both ends of the axle shaft is splined. So you never have the full weight of the vehicle on the axle shaft itself. Our vehicles use hub/wheel bearing units on each end of the axle tubes that the weight of the vehicle is on. So basiclly your Commander can handle a lot bigger tire then you would ever be able to fit.
 

·
Registered
Joined
·
36 Posts
Discussion Starter #13
I don't remember that being the case with the 8.25 in my XJ. I do know the 8.25 is a good axle.

So, I was out crawling around on the garage floor and I confirmed that I do have a lift on my XK. Looks like a 2" spacer lift, couldn't see any markings to indicate which brand but they are poly spacers that are molded to orient the springs correctly. I suspected it did have a lift since it seemed to sit very level. Made the wife happy to hear since she was asking about one on the test drive.

We have the factory 18 wheels and 255/70r18's on it now. Not a fan of 18's and the lack of tire choices, plus the 18" tires are pricey. I think we are going to get some new wheels (17") hopefully before the snow comes since the current tires aren't in great shape. Now I need to decide if I want to go with the stock 245/65r17 or go with something a little bigger. Since I have the lift and will be going with a different offset wheel I guess I have more options. Have you all seen a big drop in gas mileage with bigger tires? I won't be going too aggressive on these tires (Falken Rocky Mountains) but I was hoping I could get half decent (for a jeep) mileage. Right now I am leaning towards going with the stock 245 size but the jeeper in me is saying go bigger.
 

·
Registered
Joined
·
88 Posts
Right now with my lift, full skids underneath, HEMI with CAI and heavy foot I get 12-13 city and 15-16 highway. Here is a thread on the other forum discussing mpgs http://www.theultimatejeep.com/showthread.php?1992-MPG-updates
You may have the daystar lift which I had before my OldManEmu..
I love the look of my 265/70/17 but I have stock wheels so spacers are needed, it gives the XK a nice broad stance. This is pretty much the largest tire you can go before major trimming is needed, a pinch weld mod will be needed with this size. Post some pics of your XK!!!
 

·
Registered
Joined
·
36 Posts
Discussion Starter #15
I will get some pics up this weekend. I haven't been getting home from work until almost dark and taking pictures of a black jeep in the dark with a camera phone doesn't net great results. I need to get it all waxed up.

On the first half a tank we have run, we are only seeing 10.9 on the onboard screen, no idea how accurate this is. I know on my JK it isn't too accurate. I would be happy to see 12-13 around town.

I plan on doing plugs soon which should help the hemi be happy and maybe help a little with the mileage. I also don't know if the jeep was flashed for the bigger tires. I also want to do a full work up on the fluids.
 

·
Registered
Joined
·
88 Posts
What fuel are you using?!? I was using 87 for awhile getting horrible mpg, 9.6!!! Its discussed in the link I just sent. I go with Sunoco 89 before now 91 cause of my tune. Also after I installed the CAI I saw a nice jump in mpg, something you might want to consider if you dont plan on going thru deep water and want to hear that HEMI!! If you dont have a tuner it probably hasnt been flashed but my EVIC was only off by .5 the most, I just calculated the miles til empty with the trip odo.
 

·
Registered
Joined
·
36 Posts
Discussion Starter #17
I am assuming it just has the low grade fuel right now, we haven't filled it up yet. I will try mid-grade the next time around and see if it makes a difference. I will also look into a CAI if they seem to work on this rig. I have had CAI on other vehicles and have never seen a difference in mpg or performance. My wife did just get back from taking the kids to the zoo and said it was now saying she was getting 12.5mpg in mixed highway and in town. That is better.

Do programmers seem to help the fuel economy? I don't know if I need more performance but the tow curve could be nice and if it gains a mpg or two that is nice
 

·
Registered
Joined
·
301 Posts
For some odd reason my mpg jumped from 13.8 to 14.7 in my 4.7 after I hit 80,000? My jeep loves me!


Sent from my Autoguide iPhone app
 

·
Registered
Joined
·
36 Posts
Discussion Starter #19
I made my first repair. The sunroof wasn't closing properly, the glass was lower on the front then the back. There are four little torks screws, you just loosen them up and adjust the window where it should be and tighten them down. One of them would tighten but wouldn't hold the window tight, like it was bottoming out. I added another washer to it and tightened it up and it looks great now. I noticed I had a leak the other day when I was washing it, I don't know if while washing it I was overwhelming the drain because the glass wasn't sealing, or if the drain is plugged. Either way, I am going to check the drains and make sure they are open. I can see where they terminate outside and I can totally see how the end could clog. I just wish you could reach the little suckers to cut the end off.
 
1 - 20 of 20 Posts
Top