69 J4000 Axles??

[RamJetFSJ]

Ok, im looking at a 69 J4000 thats for sale in my area. Before I drive out to see it, I was going to try and get as much info as possible on the axles.

First of, what does the 4000 mean? Is that the weight rating or wheel base or what?

The IFSJA drive train database shows that it will have a 44 front. Can I use the parts off my 80 44 front to make it disc brakes?

It also shows the rear as either a full or semi floating 60. Are J4000 Z code trucks, or would I just have to check the vin to be sure?

Next what gears do these usually come with?

What about bolting them up to my 80 wag. Front springs should be in the same place right? The rear is differend so Id just have weld new spring pads on right?

Its an auto with the 350. The trans is a TH400, right? What would the transfer case be?

The front axle would be passenger side drop right? What would the rear be, center or passenger side?

And last, how much wider will the axles be than my NT wag? About 6"?

Any other info would help if it comes to mind too!

Thanks!

[Blackjack]

Ben,
The 4000 is just 3/4 ton designation Jeep used. There were different GVW ratings for the 4000 ranging from about 6000 to 8400 in the later J20.
Discs can not be retrofitted because the early D44s had closed knuckle front ends.
Check the VIN I think the 6th or 7th letter if it's a Z it's a 4800 or 8000 GVW truck with probably D60 FF rear axle.
Gears could be 4.10 or 3.92
Front end is spring over from the factory. Wag is spring under. Probably a fair amount of work to get it to work.
Transfer case should be a D20.
Rear diff should be a passenger side pumpkin. not sure about the width. I had a '71 J4800. they're a tough truck but I felt the closed knuckle front end with the long turning radius was a drawback.
If you want to buy it to strip parts for your wag you'd be better off to use a later model J20.
Just my $.02. ;)

[RamJetFSJ]

Thanks! I needed the $.02 worth on this one. Any suggestions on what year J20 to look for? I have a driver side drop right now on my wag. Did they make J20s with driver side?

Im going to do a SOA if I swap in the bigger axles anyway, so that actually good if its factory SOA.

How bout this idea: Swap in the drivetrain into my 73 wag parts car. Drop the J cab on and cut the bed down to fit the frame and make a short wheelbase J truck (it will be built for the dirt almost exclusively.)? Anybody done this or seen it done? Think it will be cool? Probably 8 or 9 inches lift from the stock 73, Ill use the better condition springs (but still way flexy), left over from my 80 wag. 36 or 37" tires, revolvers and tons of flex!

Are the closed knuckle fronts really that bad. Is there no way to put discs on them? What year Js didnt have closed knuckle fronts?

[River Beast]

Sounds like you gotta good plan... I wll let you know that there are differences in the J Truck frames and Wag/Chero frames... but mods should do the trick.

Good luck...

[RustyJeep]

The front spring perches are wider on the old J's. This is because they use side hung springs like the rear of old wags. This makes it a little more difficult. Also, at least on mine, the frone springs are just 2" wide, not 2.5" like on newer rigs. Spring eye bushings are different, too. Umm...after 74, they switched to open knuckle front axles, I believe.

[RamJetFSJ]

Thanks for the info Rusty. I think Ill have to think this trough a little more. I would like to put wider axles on my wag, but i would like to retain the driver side front drop and center rear. Id also like to go to a 60 in the rear, for strength and so I can put some disc brakes on it. Maybe ill start looking at some other rigs, like dodges and fords to find something that will work.

Thanks for the info!

[Gladi8r]

The J4000 simply means that the truck is a long wheel base(132") as opossed to the J2000(120"). J4000 is a generic name given to all long wheel base pickups of that era.

Not all J4000 are 3/4 ton. There is a model code in the VIN that will give you further info on the weight class of the vehicle.

3408W <-- J4500 <-- 5000 GVW
3408X <-- J4600 <-- 6000 GVW
3408Y <-- J4700 <-- 7000 GVW
3407Z <-- J4800 <-- 8000 GVW

The above are all 132" wheelbase J4000 pickups, the 120" are only available in 5000 and 6000 GVW and are 2406 W & X respectively. I have a TSM for the Gladiator pickups if you need any further info.

[ April 23, 2002: Message edited by: Gladi8r ]</p>

[Josh D]

I think the closed knuckle axles can be converted to disc brakes using a combo of chevy, ford and CJ parts. Two main reasons for not using this axle is turning radius and the small 260X steering u-joint (same as dana 27 and 30). Later open knuckle 44's use the 297X u-joint, much stronger if you plan on running big tires, low gears, and or a front locker. Use '74 and up years for axles to swap.

Josh