Overland MJ am I nuts.

Waytec

Adventurer
So here is what I have dug up. 4:56s will give me lots of torque. witch I love in my XJ on the trails. but the top end is not there. I need 110km/h to 130km/h with no issues and not be a hog on fuel. So with 4:10s with 33s will get me back to almost stock gear ratios.
I am getting stocked about this one agene. I just need to get the XJ engine swapped and moving then I can start on his one.
 

JCMatthews

Tour Guide
I ran the 4.56 33X10.50 combo on my XJ that I sold last week. I got in the high teens for fuel mileage, and ran at about 2350 rpm at 65. It had the AX15. I would not have gone with anything higher in the axles. It was great at all speeds.
 
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Waytec

Adventurer
How was it at 75 mi/h. That converts over to 120km/h and that is what the average on the roads her in Alberta are. Cops don't tent to bother you until the 130 to 140 mark.
 

BEVAN

Adventurer
I'm hoping to find a 4Cyl 96+xj at the boneyard so I can pull the axles (4:10's)and do the upgrade for $ 150.00- if I wasnt so cheap id pick up some 4.56's .
 

Root Moose

Expedition Leader
How was it at 75 mi/h. That converts over to 120km/h and that is what the average on the roads her in Alberta are. Cops don't tent to bother you until the 130 to 140 mark.

Yep, same here in Ontario.

Have you done the maths on the RPM at speed? With a heavy, tall, big tired truck you don't want to be under geared. This is why everyone is saying 4.56. If you are thinking that 4.10s will save fuel then don't. The engine will be lugging on hills and you'll have your foot in it and you'll burn more fuel. You want to have a little more gear to compensate for the extra weight of the Jeep itself and the rolling inertia of the big tahrs.

I used this calculator to compare the stock setup to 33s/4.56:

http://www.grimmjeeper.com/gears.html

I didn't know what transmission you had so I threw in AX5 for the 2.5.... may be incorrect. Also said factory gears were 3.55 which may not be right.

OEM Speeds at 65 and 75 mi/h: 2431 and 2805

4.56 Speeds at 65 and 75 mi/h: 2565 and 2960

4.56 w/ AX-15 at 65 and 75 mi/h: 2384 and 2751

4.56 w/ AW4 at 65 and 57 mi/h: 2263 and 2612

Really, do the 4.56s. We are talking about 100-150 RPM. The 4.56 gets more multiplication when in low range. If you have a AX5 now it will just be a matter of time till you upgrade it to something else as they don't seem to like to live behind built Jeeps.

Now, if you have a set of factory 4.10 axles lying around that is a different scenario.

 

cocco78

Adventurer
I love MJ's... Only problem is the cab is a bit cramped, but its relatively comfortable. I have an 88 that i'm building strictly for a wheeling rig... If I found a nice one I could see putting a flippac on it and going around the country with it...

spyu55.jpg
 

Root Moose

Expedition Leader
Yeah, I'm going to do a Flippac eventally. I compared to a fourwheelcamper but the weight makes the truck nonviable as a race car trailer towing machine if I go with a slide in. It bumps the weight up enough that I'd need annual inspections to be legal and I'm not interested in that.
 

JCMatthews

Tour Guide
How was it at 75 mi/h. That converts over to 120km/h and that is what the average on the roads her in Alberta are. Cops don't tent to bother you until the 130 to 140 mark.

I'm not sure. I sold the Jeep and can't tell you. I had the AX15 five speed and the transmition gears were quite tall. All I know is that it was not bad at all. It was probably really close to 3000. I never wanted to drive my lifted Jeep that fast anyway It never really liked to go more than 70 mph from the time I bought it @ 22,000 miles. However, when I needed to pass someone it never hesitated going 85 mph, and then I'd slow back down.
 
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chp-sk8

Adventurer
My MJ

hey guys...it is awsome to see the interest in the MJ's. Finished mine about 3 years ago:sombrero:. Here is the run down of what has been done.

1989 mj rust free cali rig.
ax15 tranny, on a terra low 4to1 transfer
Front and rear dana44's, built with cromo axels, ARB's, 4.56 gears
Currey steering linkage, and disconnects
Custon longarm kit (did 815 on the RTI):coffeedrink:
Custom bumper front and rear
Full armor underneith front to rear
belly Rock lights, and hella drivers
Long Bed bobbed to short bed specs
Interior cage
Interior is Mint (With stock buckets)
Jeep Recon Green Paint, Cage is paint matched too
Bushwacker cutout fender flares
Drive line is all fresh...or was I have 30k on it now
Eng turned 200k on my last outing

I drove this daily for 13 months and pulled several 1k trip out of it without a hitch. Freeway at 75 all day....great rig!

I would love to post pics but I cant from here...I am Deployed in A-stan right now. I can send them to someone if they could post them for me that would be great. here is my email-- ( deepblue828@hotmail.com )

I was thinking of selling a few months ago, but It is parked in my shop next to my 53 Willy's Pick-up....they need the company:D

Thanks guys
 

MuckSavage

Adventurer
I recall reading an issue of 4wd & Sport Utility some time ago where there was one of their exploration articles (you know the ones where they state historic facts & give GPS coords) Well there was a beautiful black MJ, appeared to be very well tricked out. They didn't give much info on the rig, but it was a beaut!
 

Root Moose

Expedition Leader
Good job! Race you!?

Went to strip one of my YJ carcasses this weekend for my next project. Need a frame for my "good" YJ. Flipped it over and started wailing on the frame with the bodyman's hammer. It's soft in all the classic YJ soft frame spots. Guess I better call the wrecker since that is all I had that carcass for.

Looks like I'm starting the MJ in the next week or two. :D
 

OverlandZJ

Expedition Leader
Your gonna get a big jump on me. Bought an abandoned project minus... most of it. Southern truck with no rust.

It's 12hrs from me in Ga, it'll be a bit before i get down there to pick it up.
 

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