New Axle Disconnect?

[rbattelle]

The Sept. /Oct. issue of Truck Trend makes a strange claim about the front axle on '03 HD 4wd. They say axle disconnect has been eliminated, so that:



"the front end is always turning and engaging front drive is easier. Fewer moving parts simplify servicing, and the aftermarket is no doubt working on a manual locking hub conversion already".



This seems to be a contradiction: if axle disconnect is gone, and the front axle shafts are permanently connected to the wheels (i. e. always turning), then why would you need hub locks?

 

[Sageair]

I believe what they meant is that some body will come up with a manual locking hub so that you can completetly disconnect the drivtrain from the rotating wheels to reduce wear and improve milage. If there is one thing I wish my 2001 had it would be locking hubs.

 

[nickleinonen]

doesn't the little jeep tj use that kind of system?

 

[David Muench]

Yes, since '97 on the wranglers and since '98 (I think) on the Cherokees. It's a nice reliability improvement, but it may kill the idea of 2-low kits.

 

[nickleinonen]

true the 2 low won't work then [unless you put in hubs up front] but how many actually use 2 low? isn't 1's low enough, considering 3. 73 is the new highest rear gearing [not 3. 55 as 2002]?

 

[David Muench]

I use it a lot on my 2001, for maneuvering trailers into tight spots. It's really effective when combined with a front reciever hitch. I may not miss it as much going to an automatic though, hard to say. .



(And my 2001 has 4. 10's)

 

[raiste]

Originally posted by nickleinonen

doesn't the little jeep tj use that kind of system?

The 2002 trucks built after about Jan. have this "feature" as well. I don't mind it in mine. Keeps most of the front end lubed up all the time.

 

[DDahl]

The lack of an axle disconnect brings us all back to the very bad days of Dodge (when they were driving themselves out of the truck business). I had a friend who bought a power wagon RAM 250 4X4 and the front axle was a semi-float with no disconnects. No one but Dodge was dumb enough to do that at the time. The semi-float axle prevented the use of hubs. This made the Dodge a WWII class rig (everything spins) without the option of hubs. I hope DC managment is not in the process of becomming totally non-competitive in the heavy duty pickup business.



Let's see: No crew cab (ignoring sales trends), very restricted engine access for styling reasons (stupid), a totally non-competitive 4 speed automatic transmission (unbelievable), and not including serious improvements like: variable geometry turbos (great low-rpm torque -- i. e. as on the new ISBe), a tip forward hood (for easy access), or more important -- dual torque curve engines that would produce 700+ ft lbs in the two highest gears (like real trucks -- when the existing drivetrain could stand it easily) to make the gen 3 into a towing monster. The DC Germans don't appear to be very interested in the heavy duty pickup business!!

 

[David Muench]

That's not fair at all to compare the new no-disconnect system to the Power Wagons. I had a '79. The PW had a full time 4wd t-case (HI, LOCK, NEUTRAL, and LOW if I remember), and bearings that weren't the most efficient. The new Ram's will have very efficient bearings, and it won't be running power through the front driveshaft in 2wd.



It's proven itself in the Jeeps (though serious wheelers convert to hublocks), and while it's not the best solution (hublocks), it's certainly an improvement over the old disconnect system (weak and prone to freezing up). I've also had a Jeep TJ and my wife had a Jeep YJ. . Both ended up being converted to hublocks, but before that the disconnect in the YJ was a real pain. My 2001. 5 Ram has the disconnect too, and thankfully it hasn't acted up yet. . But I don't offroad it.



The only real disadvantage I see to the new non-disconnect system is we won't be able to do simple 2wd-low kits by just fiddling with the vacuum lines. . Either need to convert to hublocks or install a modified shift fork in the tcase.

 

[DIESELMAN]

Regarding the ratio change... .



Unless you change tires, the Rear end ratios were changed to keep the overall ratio with same transmission's similar to the '02 and before, ie.



6 Spd at 800 RPM, 1st gear, Old 265-75R16 /w :3. 54 = 3. 7MPH, the new 265-70R17 /w :3. 73 = 3. 6MPH



Or the other end of it



6 Spd at 2200 RPM, 6th gear, Old 265-75R16 /w :3. 54 = 80. 3MPH, the new 265-70R17 /w :3. 73 = 75. 9MPH



About a 100RPM difference runnin' legal down the freeway.



:4. 10's are cranking 2400 RPM at 75MPH.



Man, I sure know how to waste my time waiting for my new truck!

 

[DDahl]

I personally much prefer locking hubs too. However, if the 3Gs use the same approach as in the 2002s, we are talking about a semi-float front axle. This means that it must be converted (by the owner) to a full floating front axle ($$$) BEFORE hubs can be used. In other words the Dodge owner must spend big bucks just to bring the front axle up to a level that Ford super duties come with stock.



That strikes me as DC cost saving STUPIDITY!!! The same form of cost saving stupidity almost got them out of the pickup business years ago.

 

[David Muench]

How do you figure the 2002's use a semi float front axle? Granted, I have a 2001. 5 right now but AFAIK the only changes to the front axle were the elimination of the axle disconnect and the silly breather in the diff cover. To make a semifloater front axle, it'd require changes outboard of the knuckles.

 

[DDahl]

Unless your 2001. 5 is different from my 96, it has a semi floating axle. Pull off a front hub cap or wheel (as may be necessary). Now look at the wheel center if you see a piece of axle and a large nut sticking out, you are the proud owner of a semi floating front axle. In contrast look at the rear axle. It has a full floating hub with diff oil in it. The front end of my 96 (and for all I know all 2G trucks) rests its weight on the axle shaft itself (semi float) and not on an extension of the axle housing (full float design as used in current super duty fords and most all WWII 4x4 including the jeep). DC got away with the semi float design because they used an axle disconnect (because hubs cannot be used on a semi-float axle).

 

[CJ Lagos]

The front axles are most definately full-floating. Full floating simply means the weight is on the axle housing.



On our full-time front ends the weight is being placed onto the wheel bearing hub assembly that is bolted to the knuckle. The axle shaft is not carrying any of the vertical load. You can remove the axle shaft and still have the weight of the vehicle supported.



On a semi-floater, the wheel actually bolts to the axle shaft itself.



CJ

 

[David Muench]

Exactly what CJ said.



I've never actually seen a semi-floater front axle, but I have been told there are a few rare ones that do exist.



FWIW, the Jeep Dana 30 front axles are also full floaters, both with or without the disconnect. And they use the same type setup as the Ram, although smaller in all regards of course.

 

[DDahl]

That sounds like a full floating axle to me too. However, DC refers to the 44/60 front axles in its 96 factory shop manual (3-15) as follows: "The axles are equipped with semi-floating axle shafts, meaning that loads are supported by the hub bearings. "



Semantics aside, I am unaware of any way to add locking hubs to these axles without replacing a lot of parts. Do you know anyone who makes locking hubs for these front axles?

 

[David Muench]

Just looked at my 2001 shop manual as well, and the same phrasing is in there too. But it's got to be a misprint, as "semi floating axle" and "loads are supported by the hub bearings" are contradictory. It's definitely a full floater looking at the pictures, and is of the same type Jeep's been using on their Jeeps since at least the '84 Cherokee.



It does require replacing a lot of parts - specifically you need new outer axle shafts, spindles, hubs, and some hublocks. Dynatrac makes a kit that's expensive both because it's Dynatrac and because up till 2002 they had to include a specially machined inner axle shaft to replace the disconnect side (and seals and such). Theoretically you wouldn't need that on one of the new non-disco axles, and the kit should be cheaper. If it were Warn instead of Dynatrac, I'd think a non-disco kit would run about $1,000 given that their Jeep kits are about $800.



Not that I'm knocking Dynatrac at all, but their parts do carry a premium price.

 

[DIESELMAN]

Since the first race behind the nut/washer on all non free-wheeling hubs carries a sheer load, and that is one of three load bearing faces in the hub assembly, they are all technically sem-floating load bearing axles.



The majority of the sheer force is shared between the inner and outer spindle bearings, well in excess of load requirements.



You could still remove the outer axle shaft and reinstall a wheel and it will work but some of the load bearing capability is removed.



Free-wheeling hubs remove the connection and shock load transfer of the axle from the housing, and the outer axle bearing is not a primary load bearing structure, therefore these would be considered free floating and are just like a free-floating rear end. The outer axleshaft is allowed to slide in and out along the splines, and rotationaly to the degree of slop in the engagement gear, limited by the axleshaft bearing and seal.

 

[benhall]

For everyone that has the 2nd Gen 4X4, Dynatrac has a conversion for our Rams to convert them to manual locking hubs. Go to www.dynatrac.com and ask about there conversions for this. The are running from about $1500 for a basic conversion and all the way up to $2500 for new axle shats that are 35 spline, not 30. They all come with Warn locking hubs. I'm doing this when I leave Germany.

 

[tarussell]

I don't think that Dynatrac offers a provision for 2nd Gen. 's with A. B. S. The manual hubs would be great but I don't want to loose the anti-lock brakes.