Regearing and Traction-aid

OK while doing some mild wheeling in the Calico’s over New Years weekend my wife made the comment, “Why don’t you use the tax refund to do some work to the Jeep?” So that got me thinking. I have a Dana 30 upfront and Chrysler 8.25 in the rear, open/open, automatic-transmission, 235/75/15 tires on stock rims, OME 2.5’ lift. The only other lift mods I’m thinking of are coil spacers up front and longer shackles in the rear.

I was thinking of 31” All-Terrains, and am looking for suggestions/comments on re-gearing and adding a traction-aid.

The XJ is a DD and I frequently tow a tent trailer. Should I go with 4.10 or 4.56 gears? Or are the stock 3.55 gears adequate?

After doing some surfing on the web, it seems that my choices for a traction aid for the Chrysler rear end are limited to either a full locker or a limited slip differential. Am I correct?

With the automatic go 4:56 w/ 31's" 3:55's will dog especially going uphill. As for as traction goes I wouldn't bother with the limited slip. Detroits aren't bad for a DD as long as you don't gas it around corners.

I have a similar set up on my '98.... D30 up front with a TrueTrac and an 8.25 in the rear with an Auburn Limit Slip; combined with 4.56 gearing. I'm running 32's though, and it runs great! I too would vote 4.56's even though you have 31's. Who knows, you may upgrade tires in the future.... 4.56's will cover a wide range of larger tire sizes....

I hemmed and hawed about doing a locker in the rear. With my rig being my primary daily driver, along with all the rain and snow I have to deal with; I felt Limit Slips front and rear was the best safe solution for me. Your situation may vary, but be honest with yourself and don't get caught up in a "Locker is the only way to go" frenzy....it really does vary by individual situation. YOU decided which type of traction aided device is best for you....

Ivan

karstic said:

OK, my wife made the comment, “Why don’t you use the tax refund to do some work to the Jeep?”

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Your wife didn't really say that......... hopefully you taped the conversation for future reference.

Now, how big is this Jeep upgrade budget? Making some assumtions, adding a budget boost to the OME lift is a bandaid. Other's have tried this and wound up with a saggy setup. I would throw the OME stuff on the 4 Sale board and go up to at least 4" to run 31's (RE 3.5" will net you 4"). BFG AT's are a good choice for all around use and get respectable treadwear as well. Don't forget longer shocks too.

With the DD status, I would go selectable locker in the rear (not sure what the 8.25 options are, never payed much attention since I've never owned one) or a good limited slip such as a Detroit Truetrac or Auburn Pro-Series. I never notice my Auburn Pro on the street but it works nicely offroad (on slickrock it thinks it's a locker....ssssshhhh ) and I would run a Truetrac again in a heartbeat.

As for gears, do it once cause the odds are that you'll add more lift and tire later, so 4:56's will work with 31's-33's just fine. 4:10's will not...... ask me how I know?
Don't forget to factor in an SYE kit with the added lift and a longer HD driveshaft (Tom Wood's makes a nice combo setup)...............so about that recording of your wife's comment.........was $$$ ever discussed?

I wouldnt do 4.56's for 31's.I run 4.10's with 33's and I am exactly the same RPM's as stock.Ive never changed speedo gears and speedo is aslo right on!

Your wife didn't really say that......... hopefully you taped the conversation for future reference.

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Yes she did... She likes wheelin' as much as i do, she even wants here own Cherokee. We saw some XJ's from the Bakersfield Trailblazers run up at Calico and she got this glassy look in her eyes.

I would go selectable locker in the rear.

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Unfortunately a selectable locker is not an option (at least I haven't found a company that makes one for the Chrysler rear-end)

I'm getting yay's and nay's on the 4.10/4.56 question. So, what are the pro's/con's of each gearing?

I don't have the desire to go with much more of a lift than I already have, just enough to clear the 31" tires and I don't want to deal with SYE issues.

SUGGESTION: Why not stay with the stock gears and add a Lock-Rights to the front and rear? If 31's your staying with for a while then I wouldn't swap gears yet. Later if you want bigger tires change them then with the tires. Spend the rest on Rock rails, Winch, Stereo, whatever. I've got 5 inches of lift with 31's (stock gearing) with Lock-Rights and I get 14 to 16 mpg. But then you'll get someone on here to say Bullshit! So I guess it's up to you? Frankly Why make more work and money then need too.

karstic said:

......wife made the comment, “Why don’t you use the tax refund to do some work to the Jeep?” .....

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Dude, should you ever get sick or something, and DIE, tell your wife about me.
I'm 27 years old, socal blonde hair with dark blue eyes. Six-pack abs. Good job. You know the stuff. (801) 555-1234

Come on over to my place sometime and you can play on my swing. :hang:

I'm pretty sure there's an ARB for the chysler 8.25, 29-spline. If you have the 27-spline, you can always upgrade to the 29.

hondastomper said:

I'm pretty sure there's an ARB for the chysler 8.25, 29-spline. If you have the 27-spline, you can always upgrade to the 29.

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Hmmm how about a no slip for the rear? It's nice, but I will admit that it does take a little bit of getting used to it? And yes.. definately regear and for 31" go for 4.56

I am running 32'S with an auto and stock 3.55 gears with no problems. I also have a No Slip in the rear and do not notice it. My rig is also a daily driver and gets a lot of mileage. If you are near the Ventura area you are welcome to test drive it and get a feel for how the combo works. I guess the real question is how much $$$ are you going to have to play with. As for suggestions, the cost can vary significantly from the add a BB to lock and regear.

I'm running 31's with a Detroit in the front 30 and with a 5-speed. I have a friend with an auto and 4.10's and 31's. With the auto, 4.10's are fine with 31's, you don't feel it much. I'd go all the way to 4.56's with your auto. With a stick, 4.10's are pretty low with 31's, just about right IMO. With the front axle, you can put in any locker and you'll only feel it in 4WD, but it will affect your steering in 4WD. I love it though and steering it not that bad.

xj92 said:

I'm running 31's with a Detroit in the front 30 and with a 5-speed. I have a friend with an auto and 4.10's and 31's. With the auto, 4.10's are fine with 31's, you don't feel it much. I'd go all the way to 4.56's with your auto. With a stick, 4.10's are pretty low with 31's, just about right IMO. With the front axle, you can put in any locker and you'll only feel it in 4WD, but it will affect your steering in 4WD. I love it though and steering it not that bad.

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XJ92... if I had to do it again I'd put 4.56 for my 31's and stick. Btw, my XJ is a daily driver (about 120 miles a day).

Anyone care to give a rough estimate on how much it would cost? I figured $600-$800 in parts, but I have no idea on labor costs.

Since you plan on towing I'd go 4.56, between towing and the fact that in a few years you might want to bump up in size again (it happens...)

Kejtar said:

XJ92... if I had to do it again I'd put 4.56 for my 31's and stick. Btw, my XJ is a daily driver (about 120 miles a day).

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I just measured my tires again, and they're almost bald and are down to about 29 actual inches. So on a 31" tire that is actually 31", I'd probably get 4.56 too.