Here we go, the Jana 87 is a reality. Shown pictured is a D60 35 spline spool modified to hold a D80 5.13* ring gear in D70 housing. The D80 is rated at 10,000 ft-lbs momentary output torque where as the D70 is 8,000 Ft-lbs
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From doing research, and experience with my other Jana Hybrids I can assure you the following. This will work in smooth bottom 70s, 70 HD and all the rest. We will be able to take a The 40 spline Dana 60 ARB (RD167) 4.10 & DN Locker, do minimal machine work to it and run 80 gears on it.
The path of least resistance here is using the High speed 4.10 & DN carries so that only re drilling the bolt holes is necessary, however in most cases a D60 or D70 4.56 & up carrier can be utilized with some machine work on the bearing shoulder. This conversion is easiest with 70HD carriers but all carriers can have the bearing shoulders machined to work.
Now let the Jana 87 Rockwell outer hybrids begin!
*Pattern looks pretty good for a used gear with 300,000 miles on it.

If you found this thread you'll also be interested in our full product line of Differential Hybrids;

HOW TO INSTALL:
D70s into D60s, Jana 76:http://pirate4x4.com/forum/showthread.php?t=946421
D50 into D44s, Jana 54:http://pirate4x4.com/forum/showthread.php?t=948996
New 8.9" JKs into 44s Jana K4:http://pirate4x4.com/forum/showthread.php?t=957491
Holding it all together; Jana Cover Girdles http://pirate4x4.com/forum/showthread.php?t=948996

This is a D60 spool, re-drilled and a concentric register ring pressed on for the Jana 76 application. When I was working on the Jana 87 I just did not want to heft a full heavy carrier in and out until I found the right shim, bearing & offset combination, so I machined it to work with the 80 ring gear.
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The spool is now machined so it will work as a light weight installation tool along with a stack of shims & dummy bearings for All combinations, of 4.10 & DN, 4.56 & UP Dana 60, 70 & 80! If you set up more than one of these a month, it's the biggest back & muscle saver you will ever use, I was nearly able to install an 80 ring gear in a housing one handed. After getting the shims stacks figured out for proper ring gear set up using the dummy carrier, you can then quickly get a locker in by comparing and adjusting shims to the same dimensions from the dummy carrier. Its easy with a height gauge on a good flat surface but can be done with calipers, a strait edge, and some math as well by comparing the distance of the ring gear flange to each bearing outer race and adjusting shims till the dimensions match.
I got my height gauge from eBay very reasonably priced.
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Fawesome!

J. J.

Jesus, this is awesome,
I just aquired a dana 60/dana70 combo.
Got mega beef?

So I was wondering what I was going to do for a cover as putting the D60 covers on the Jana76 required stretching it about 3/8" of an inch. I picked up a Rough Stuff cover and low and behold it fit. Like whoa that's cool. It fit because the D70 housing cover gasket surface is farther back from the center line of the axle than a D60. So then I tried a stock 60 cover and discovered it fit as well, and there was plenty of housing to be trimmed away for ground clearance. Now I've seen many D60s shaved to nearly the edge of the bottom cover bolt, mine included, and they have survived just fine. So looking at the casting on the D70 I see no reason it can't be shaved down so that you have within an 1/8" the same ground clearance as a shaved 60.
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The pics show a stock 60 cover with a conservative shave and the out line left for removal on the 70. The notch I put in this housing is a little generous so the next one will have even more meat left on the bottom to work with.
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Wow, just wow. :eek:

I have a question about the D60 spool, would you run it? The D80 bolt pattern seems awful close to the edge, do you think it would crack from the hole out to the edge? I'm not haten, just thinking because I have a 70 spool I'd want to reuse when doing this conversion (I reallize my 70 bolt pattern and flange would be bigger than the 60).

Also, would you do the slug/redrill work on customers diffs/spools?

Also would you say that this will be as strong or stronger than a 14bolt front?

Wow, just wow. :eek:

I have a question about the D60 spool, would you run it? The D80 bolt pattern seems awful close to the edge, do you think it would crack from the hole out to the edge? I'm not haten, just thinking because I have a 70 spool I'd want to reuse when doing this conversion (I reallize my 70 bolt pattern and flange would be bigger than the 60).

Also, would you do the slug/redrill work on customers diffs/spools?

IIRC is clamping force that holds the ring gear on, not the shear strength of the bolts.

Please correct me if I'm wrong - that is just what I thought on that...

D80 gears in a D70, whoa. Super cool - this would be badass in a front axle...

Wow, just wow. :eek:

I have a question about the D60 spool, would you run it? The D80 bolt pattern seems awful close to the edge, do you think it would crack from the hole out to the edge? I'm not haten, just thinking because I have a 70 spool I'd want to reuse when doing this conversion (I reallize my 70 bolt pattern and flange would be bigger than the 60).

Also, would you do the slug/redrill work on customers diffs/spools?

Correct, its the clamp load of the bolts creating a static friction drive, not the shear load on the bolts that drive the ring gear. think of it as a clutch with super springs (bolts) applying the pressure. So it would work even if the holes were slotted.
Yes we will do the slug re-drill work on your carriers. Spools are nice, just re drill in between the holes that are there. Figure approximate pricing as follows:
Redrill a 60 spool to 70/80 bolt pattern $70/80
Provide Concentric Ring gear register ring for 60 carriers $40.
Redrill & plug most lockers $150, Air lockers $200.

Also would you say that this will be as strong or stronger than a 14bolt front?

Good question, I am currently working on a Double ring gear load bolt installation kit. With the excess D80 ring gear that hangs over the edge of the smaller carriers there is room to install a pair of load bolts in the pinion snout that will ride on that excess ring gear surface. Although 14Bs and 70s use the same carrier bearings, the 14Bs are wider apart than the 70s thus reducing the effective loads on the bearing, with a load bolt system installed this will eliminate that factor.

would you be able to use the 37 spline dana 80 stuff in a jana 87.

sounds like a nice way to use factory 80 shafts and add more beef to a 70 while gaining the ground clearance over a stock 80.

this is a sweet mod! ive got a ford kingpin dana 70 front axle for sale if you want to build the ultimate front diff.. im located just north of washington in BC canada. pm for details.

would you be able to use the 37 spline dana 80 stuff in a jana 87.

sounds like a nice way to use factory 80 shafts and add more beef to a 70 while gaining the ground clearance over a stock 80.
Yes.

I just noticed that Yukon IS making 5.38s for D80. Prior to this 5.13s was as low as you can go.

I was wondering what modifications you had to make to the pinion bearings to set the depth correctly. I saw on your 76 that you machined the inner bearing race so that it would sit farther into the housing. Did you do that on the 87 as well? I was also trying to visualize where you are talking about putting load bolts on the ring gear but I can't seem to picture what you're saying in my head. Do you happen to have a picture of what your planning?

I was wondering what modifications you had to make to the pinion bearings to set the depth correctly. I saw on your 76 that you machined the inner bearing race so that it would sit farther into the housing. Did you do that on the 87 as well? I was also trying to visualize where you are talking about putting load bolts on the ring gear but I can't seem to picture what you're saying in my head. Do you happen to have a picture of what your planning?
for the Hd 70 you can either machine a bearing or use one that is the correct thickness. The one that is the correct thickness has a slightly lower load rating though. But its still higher that a 70 brg for load rating.
As for the load bolts, I haven't had time to perfect it yet, life and and my business keep getting in the way of R & D. But I figure if people can cut and weld all over the bottoms of these diffs to create shaved & coped housings, why not weld some bosses on the front of the pinion above and below the webbing for two load bolts. This link shows the single boss on an HO72 rear end, between a couple of ribs. http://www.google.com/imgres?imgurl=http://image60.webshots.com/660/6/90/70/2187690700068686984bypjlS_ph.jpg&imgrefurl=http://rides.webshots.com/photo/2187690700068686984bypjlS&usg=__nJoHoivUSHa764J-PuuRWiZ1BQI=&h=450&w=600&sz=61&hl=en&start=0&zoom=1&tbnid=M_fg7NiVXKxWIM:&tbnh=120&tbnw=180&ei=oaOYTaaiD6biiAK41pCdCQ&prev=/images%3Fq%3Dring%2Bgear%2Bload%2Bbolt%2Bho72%26hl %3Den%26sa%3DG%26biw%3D1152%26bih%3D709%26gbv%3D2% 26tbs%3Disch:1&itbs=1&iact=hc&vpx=712&vpy=385&dur=835&hovh=135&hovw=180&tx=120&ty=93&oei=oaOYTaaiD6biiAK41pCdCQ&page=1&ndsp=23&ved=1t:429,r:15,s:0 I will have to build a drill jig to properly locate the holes such that it will not be necessary to put the housing in a milling machine to do it. Then the jig & tooling could be rented out for anyone with a good hand drill and A welder for installation.

So this uses a Dana 80 pinion or not?

So this uses a Dana 80 pinion or not?

Yes this uses a Dana 80 ring & pinion.

And i thought the jana 76's were the hot ticket! Damn!

Well after exhaustive prototyping I have reached a solution that I like for Installing 80s into 70s. 1st off I'd like to repeat what I've said to a few inquiring customers. Yes this is theoretically possible in any 70 but unless you are starting with the 70HD or the Super 70, you will be forced to make compromises on bearing load capacity. and dropping 30 percent load capacity is not something I want to do. Especially after talking with one of the ARB techs that were at KOH this year. Seems several of the rigs running 500 Plus HP were wearing out the ring gear (left side looking in) carrier bearing in just one pre-running lap. One customer was putting so much thru the diff that he had to have the bearing changed out 3 times. Now I am talking about a D60 set up here, and a D60 uses the same carrier bearings as a D70 U. So I just want a solution that does not compromise, although some folks have said they would rather change out bearings once a year, than break ring & pinions twice a year.
So, in all the Jana hybrids I've used the following approach, move the pinion out approximately 1/4" , and move the ring gear over by selecting the correct series carrier and moving it yet approximately 1/8" over more to make room for the bigger gear sets. Well in the J87 moving the pinion out a 1/4" is not a problem but to get the ring gear where it needs to be you have to move it slightly over 5/16" of an inch. Now there are bearings, and spacers and collars that will allow you to do this, but you wind up with bearing load capacities that are equal to or slightly above a D60, but way under a D80. Also although its possible to move lockers and spools 5/16" over it is not possible to do it with an ARB because the narrow bearing race they use in the air cylinder assembly would no longer be held in by the Carrier bearing cap, after moving the carrier far enough over to work.

But don't fret and don't frown there is a way to do it and not loose any bearing capacity. Since Spicer made that ring gear pretty thick you/we can machine the 5/16" off the back of it and still have plenty of threads left over for proper ring gear bolt strength. See Picture, with thinned 5.13 ring gear on ARB HD70 (4.10 & up ) with HD bearing on left side.

Now the next trick is getting the pinion in with bearings that have sufficient capacity for reliability, The head pinion bearing is no problem in an HD or Super housing, but in a 70U you wind up with a pretty thin one. And in any 70 housing the tail bearing gets even smaller to fit the big 80 in there. So My recommendation is to have the pocket for the tail bearing machined out just an 1/8" larger and then you can use a tail bearing that actually has more load capacity than the stock D60/760 tail bearing, and this also allows the use of a seal that will fit the Pinion yoke without having to machine it down in size (Thanks JJ). Any good machine shop should be able to do this in 1-2 hours.

This is so bad-ass. You are a Genius, Carl.

I hope Carl won't get mad at me for saying this but he came up with another cool idea during one of our conversations. The extra space between the carrier shoulder and the OD of the ring gear means there is space for a load bolt to ride on the back of the ring gear if one were to build a jig, drill a hole in the housing, and weld the bung in place.

J. J.

any updates on this?? Have a 70U I was considering doing an 87 w/ but reading above makes me think shaving an 80 would be better. Or have you come up with anything new?