Axle FAQ's

What axles were used on my 5/6?

The Dana Model 25 was initially used as the front axle, however according to Willys service news of Nov. 1960, the Dana Model 27 axle entered production with serial # 57548 - 121248. Both axles were a closed knuckle design so they did not have as tight a turning radius as the later open knuckle Dana 30. Rear axle differential on all was an offset, to the right, Dana 44 with ten or 19 spline two-piece axles used, until 1970 when they became a 30-spline one-piece flanged axle shaft.

In 1972 the axles became a centered differential 30-spline flanged rear axle.

Dana 44 Rear Axle Spline Count Chart:

The spline count refers to the number of splines that the axle shaft has on the differential end.

Tube diameters:
D44 tapered 2 1/2 in
D44 flanged 2 3/4
D25 & D27 2 1/4
D30 2 1/2

What are the differences between a Dana 25 and Dana 27 Front Axle?

While the ring gear in the 25 is larger it is considered inferior due to the fact that the gear is located on the carrier with 8- 3/8" bolts versus (ten) on the 27, and the center section on the 27 is built heavier to reduce stress, and the flanges on the center section where the tubes attach are heavier.

What lube should I use on my Dana 25 axle?

Answer: Manual suggests 90wt gear oil, I believe the consensus of the list on this awhile back was to use Mobil One lube grease. You won't have to worry about spots on your garage floor and water will no longer be an issue. You can spackle most of it in when you have the knuckle apart, the fill the rest of the way when assembled. Make sure you remove any burrs on the knuckle cup...they will tear the new felt gasket and cause fluid/grease leakage. I use high temperature wheel bearing grease in my Dana 25 front knuckles. The property you are looking for in the lubricant is a stringy texture that sticks to metal even under high temperatures. I don't know of many people still using 80-90w gear oil in their front knuckles due mainly to leaks. I still run 140W gear oil in mine. It lasts a year or so before enough of it leaks out to matter, but I have fairly new seals. I think a lot of it depends on whether you have freewheeling hubs. With freewheeling hubs you can put in whatever's convenient since the knuckles don't turn that much. I don't have freewheeling hubs, so I use gear oil because I have heard that you can get cavitation with grease. They say it all spins to the outside from centrifugal force and the CV fails from lack of lubrication. There is clearly a good deal of disagreement on this among Jeep owners and mechanics. For a while I subscribed to the mil-veh list where the consensus seemed to favor 140W gear oil. But there certainly are many who use grease. I was thinking that chassis grease or wheel bearing grease just wouldn't splash around in there as the designers wished. Thick stuff just would get slung to the outside and kingpin bearings, etc. would suffer. Something oily is necessary like SAE 90 or 140. Possibly track roller grease like is used in Caterpillar rollers might be thin enough. My GPW just has chassis grease in it and I am afraid of what I might find when I pull it apart. These things were designed in the days when nobody cared if they dripped a little. When they quit dripping it was time to fill them up again. I generally stick with the original manufactures recommendations, or something close if it is available. When I rebuilt the front end of my wagon I used a 600W oil. It was used in Model A rear ends. It does flow and will drip but it won't get thrown out of the way. No problems in the winter either. Seemed to be the best of both worlds. I use Molybond and have done so for many years. It's terrible stuff to handle because it sticks to anything and has such a high graphite content, but it won't leak out, won't get affected with water, won't "spin off" and stays consistent during heat. I use Molybond in my steering boxes, steering knuckles, tie rods, bell cranks, drag links, and on all springs grease points. It's also great on things like the pivot points for the clutch mechanisms and brake pedal grease points. It *cannot* be used anywhere near brake linings. When you wish to use it in your steering knuckles or steering boxes, I recommend that you just pump it in until it's full. Then during normal driving (and when you put the Jeep away) just hop under the axle or the hood and wipe away the excess with a rag soaked in kero. Eventually, it will stop pushing out the extra grease and you won't have to do it anymore.

Has anybody had the problem of breaking the knuckle to hub bolts on a Dana 25?

Studs will just keep you from having to hold the bolt head when tightening - desirable if you remove the spindle w/o disassembling the knuckle. I'm not sure of the grade of the studs, but arbitrarily changing to grade 8 is not necessarily a good thing. Grade 8 allows for a higher torque/preload but are less tolerant of shock load. As I recall, there are locknuts on the studs which suggests to me that the designers figured that under certain conditions the tension in the stud went to zero. If that load case is true, grade 8 bolts may fail quicker than the lower grade bolts/studs. I think the above is true, regardless of what application you are changing. Personally, if I do not know the likely load cases or previous grade, I use grade 5. I replaced mine with studs from Leon Rosser. The reason for the studs is that the original bolts tend to rip out of the knuckle when oversize tires or power steering is installed. I've heard it can also happen w/ stock equipment. If the do rip out you can still do the fix by drilling out the knuckle holes and then putting in the studs. I already had mine apart so I went ahead and drilled 'em and put in the studs. (Figured I'd try to avoid taking them apart later) The studs I got from Rosser came in MOPAR parts bags. If you're interested you could at least save shipping by getting them through a local dealer. The bags had both an old and new part number on them. The old PN "930301 bolt" and the new PN = "J8124847" The install was pretty easy but I had access to drill press and arbor press which made short work of it. The only other thing that needed to be done is to grind off some of the stud heads in the 3 and 9 o'clock positions to get full turning radius back. I think I have a some pictures at home of the finished knuckle I could scan if you want. I also used bolts instead of studs on my king pins. On the knuckle lube I also went to various lists for help. I got every thing from straight gear oil to regular bearing grease and concoctions of them both. I ended up just pumping the knuckle full of high quality, high temp bearing grease. I figure it should work best and not leak as easily. The brake conversion article I have suggests changing pressing in new knuckle studs to a stronger variety, after I removed the knuckles last night I realized that mine had no studs but are threaded and used bolts instead! Is there an advantage to studs over some grade 8 bolts? The thing I don't like about studs in these applications is that the threads get gunked and rusted and wind up breaking like half of my kingpin studs. One other difference I noticed, my manual shows the kingpins being held in with bolts, I have studs (and plan to use bolts when it goes back together.

Re: knuckle stud replacement What size hole should I drill?

3/8" drill

Re: knuckle stud replacmenent Question 2:
Do I really have to use an Arbor Press or will these go in the way you can install wheel studs, by pulling them in with a nut?

Don't be afraid of this mod. It's really pretty simple and I'm pretty sure I could have done it w/ a 3/8 drill, a good 1/2 x6" bolt and a hammer (but the drill press and arbor press made it a piece of cake).

Re: Knuckle stud replacement Question 3:
How much grinding on the 3:00 & 9:00 studs?

You're basically just removing the threads. The cast iron of the knuckle is not very hard so the studs should drive in pretty easy. Make sure to remove any excess casting material on the inside of the knuckle so the studs will be able to sit flush on the surface. I think the hole towards the front of the knuckle needs the most work for clearance and most of them needed no work at all. Try to get it right the first time so you don't have to remove them over and over. Once the studs are in, trial fit the knuckles on the axle to see how much grinding you'll need to get back steering radius. Use a die grinder to work on the 3 & 9 o'clock studs. Again I think it's the ones to the front of the knuckle that get the most work and it isn't too much but you may feel it is when you do it. Don't worry if you lose a little steering radius cause you have to give some up for the larger tires anyway. Rather than use a nut to pull them in, I'd use a hammer and punch (or 1/2 x 6" bolt) and drive them in. Just keep them as straight as possible. Which brings us to the last tip. Have a rubber mallet handy when you go to put the spindles back on, the studs may need slight adjustments from the outside to get them back in line w/ the spindle holes. (Mine only need slight whacking w/ the rubber mallet. DON'T hit the studs w/ a regular hammer, it's just not worth it. Isn't it Merl who says "Never pound on the threaded end of anything"? Damn good advice. Editors note: I just omitted the studs at 3 and 9 o'clock on my knuckles. I still have a much sturdier set up and installed the spindle on the studs tightened them down a bit and then put the bolts in at 3 and 9. Less fear of stripping them out that way.

What is the difference between a floating and semi-floating axle?

Axles are classified by the way in which the half-shafts and wheel hubs are supported -- half-shafts are the two longitudinal members of the axle which 'meet' at the differential. In a semi-floating axle, each half-shaft is supported at its inner end by a bearing, which also carries the differential. At the outer end, there is a bearing between the shaft and the inside of the axle housing. This design is often used in passenger cars, as all the half-shafts have to sustain is the weight of the Jeep. In a three-quarter floating axle, there is also a hearing inside the axle housing which supports the diff, but the outer bearing is situated between the wheel hub and the axle housing, to support the weight of the vehicle when cornering. Here, the half-shaft is subjected to extra load only when cornering. In a fully floating axle, there are two bearings between each hub and the axle housing, and these carry both the weight of the vehicle and the extra stress imposed during cornering. The benefits... The wheel supports the full weight of the vehicle on bearing races. You can pull the axle without jacking up the vehicle. Just unbolt the hub and pull it out. You can drive on them in front-wheel-drive with no axles in the rear. A semi-floater has only one set of bearings instead of two and the bearings only support *most* of the weight; the rest is supported by the axle itself. Because of this the axle must be way thicker. The bearings also don't lock the wheel in place, so if you break an axle the wheel can come right off. This is why semi-floating axles have C-clips; to keep the axles from coming out and taking the wheel with it. And remember, to get at these C-clips you'd have to drain the diff and open it up. Full-floaters need no c-clips because the axles can't go anywhere; they're held in by being bolted to the wheel. In general, It's easier to work on a full-floater.

Q: Guys, I have been looking recently at putting the Warn full floater kit and maybe a locker in the rear of my 54 wagon. I was wondering if the D-44 in my wagon is the same as any other Dana 44 axle on the market? It may sound like a dumb Question, but I don't know if any changes were made over the years?

A: I just installed the Warn full floater kit and a Detroit locker in my 69 CJ-5 was cake to set up, it was the only option available to eliminate the tapered axle set up short of swapping out the whole axle housing. The only thing is if you've never set up a ring & pinion it might be best to have that done by someone that has. I suppose yours has the ten spline axles which they do not make a kit for, but they do have one for the 19 spline (which I happen to have a Trac-Loc carrier for) or if you go with the Detroit Locker opt for the 30 spline kit which is even stronger. You can get Warn's phone # from their website www.warn.com. Their customer service dept is very helpful & could Answer any Questions you might have. Oh & by the way if you have the 10" brakes the drums won't fit over the hubs unless you have the center hole machined out larger (I put an 11" kit on Mine which fit fine).

Which is the better rear axle? 2-piece, flanged or full float?

With a 2 piece it is possible to spin the hub loose from the shaft... not likely in normal everyday driving situations with stock or close to stock size tires. Once you add in oversize tires, harsh offroad driving, and or a locking differential then 1 piece is a must almost. Then the full floater goes a bit further then by taking the weight load off the axle shafts and puts it on the hub and adds the ability to still have mobility even with a broken axle shaft...... That's the short version of the story.

Will 25 gears work in a 27 and vice-versa?

No different bolt count and different diameter of gears.

What axle ratios came stock in my Jeep?

V6 came with 3.73 standard and 4.88 optional. F-head had 5.38 standard in those years, 4.27 optional.

How do I tell what ratio my axles have?

Jack up rear end, mark drive shaft with chalk, rotate tires 2 full turns while countings number of times the chalk rotates. Unless you have a locker of some sort.

Look for a tag on the differential that has numbers like 43-11, 43/11 = 3.90 Gears

Take the differential cover off and look at the ring gear, it will have the same numbers as the tag stamped on it.