J20 axle questions

[Kaiserjeeps]

I am considering a front and rear 3:73 J20 axle set for my 71 J4000. A Dana 60 and a Dana 44. 8 lug. The dana 60 would be full float with two wheel bearings per side right? Is the diff centered or offset? 12 inch brakes? Or 11?
While not a big deal, will the spring pads be in the right spot for a 71 spring pack?

The dana 44 front would be disc correct? Or drum? I figure I would need the master cylinder and proportioning valve for good stopping function. Is this axle a passenger side drop?
I don't know the year of the J20.
Any do's or don't's would be appreciated.

My 71 currently has 5 lug Dana 44's. I bought a 5 lug rear Dana 60 that is an IH axle so I was able to buy new drums for it. I would rather have 8 lug axles. Especially from another Jeep.

Am I forgetting anything other than needing 8 lug wheels?

[joe]

D44/D60 combo from a FSJ will have some specific differences depending on the year J-20 they came from. Pre-80 D60's pumpkin will be offset to pass side. 80+ will be centered. Front D44 pumpkin will be on pass side pre-80. Offset on 80+.
Disc front brakes only became std on Wags in 74, but on 74-75 J-trucks/Cheros they were still optional and not std equip till 76.

[Kaiserjeeps]

Well I called and it is a 1974 and has disc brakes. There is someone ahead of me and if he does not buy them I probably will.
I would assume the suspension or the spring pads are in a different spot on the Dana 60 housing. I will know by Thursday.
Thanks Joe.

[FleetFox]

I can't speak to the 5 lug d60s but I did swap a 1979 j20 D60 onto my project. It had a D61 from a Dodge on it when I got it . The front was the original d44 j10 axle according to the BOM code with 8 lug disc hubs swapped on. I believe the spring plates in the rear were the same for 1/2 ton and 3/4, but the U bolts were different for the bigger axle tubes. Slight offset to the pass side for the D60 as mentioned.

There are a number of pics in my build thread if you are looking for visuals.

Fleet Fox

[Kaiserjeeps]

Thanks Fleetfox. I will go see your axle pictures. So I was a day late and the guy ahead of me bought them. So I missed out. The price was sure right at 350 for both. I will keep looking. It's not a super high priority but putting stout axles like that under my 71 J4000 seems like a good thing to do. Never hesitate when something like that comes along.

[FleetFox]

https://www.fsjnetwork.com/forum/viewtopic.php?f=10&t=16965

[Kaiserjeeps]

That axle is perfect under there. Thanks for the visual! Um are those 2x4's OEM jeep? They just reek ford to me...

[threepiece]

There is a significant difference in the front spring spacing between the two trucks. They are not interchangeable without modification. There may also be steering linkage issues with an axle swap like this.

[Kaiserjeeps]

I missed out on the axles so the whole deal is kaput. But I am learning about this "new" stuff.
There is a chance I will be parting with my two J trucks. I have a potential lead on another M715. And I will see if it goes anywhere. I miss my old beauty. Now I want a non stock truck. Thanks for replying.

[Carnuck]

I put a 4 speed ‘77 J20 D60 rear in my ‘73 J4000 and I was going to weld spring pads on the matching front to go in but I rolled it on my driveway avoiding someone’s loose horse running around in the dark (downhill, switchback on gravel with no street lights) You need a pre ‘80 rear to clear the Early gas tank. Found out when I put my J10 axle back in the ‘77.

[Kaiserjeeps]

Well I found a solution. I bought a rolling shell 68 M715. It came with a 96 Dodge rear dana 70 with powr-loc extra in the bed for only a 100 bucks more.
I just road tripped again for a 83 Chevy K 30 Dana 60 front. The most ideal front end verses a Dodge dana 60 (to narrow at 67.5) and a Ford dana 60 (weak knuckles, incompatible parts, and drivers drop) so I am set.

I think I am going to part with the 71 J4000. So the axle inquiries and answers while educational and helpful, I don't think I'm going to build that truck. It has a IH 5 lug dana 60 rear axle with 12 inch brakes you can still get parts for. I bought all new drums and shoes for it. It's in the bed and there is a dana 44 under the truck now.

Anyway, thanks for the info. It's still good to know.

[Carnuck]

I might have to put my spare 6 lug rear axle in one of my Jtrucks to match the motor I have to put in. Anyone on my FB page can see the one currently under my Forward Control truck. (AKA GMC nameplate on a diesel 1994 Isuzu NPR rollback towtruck)

[Kaiserjeeps]

Sound like good jeep fun Carnuck. I know someone in Post Falls with 6 or so FC's. If you need parts or something, I could ask him... He is also always looking for them. I helped him acquire 3 of them just by driving around and seeing them and letting him know where they were.