Whats the diff between dana 30 and 35?

I went and bought some used tires and rims from a guy with a yj. When I picked them up he was showing me his jeep and offered me his old stock axles front dana 30 and rear dana 35. I've got a 30 right now in my cherokee. Is it worth puting the 35 in my jeep? Are any of the parts interchangable? I do have plans on chromoly shafts and a detroit locker. whould this handle 33s pretty good?

a Dana 30 is a front axle. A Dana 35 is a rear axle (unless you are talking about Ford axles, which you aren't). The parts are not interchangeable.

Edit: unless you mean interchangeable between the Dana 35's, then yes they are. Not sure what you are asking.

I just figured that out, i was told the rear was a 30. probably why I couldn't find info on rear 30s lol. I guess the axle I picked up will just be used for spare parts. I'm used to the deisel stuff, axles aren't generally a problem. This is my first jeep and the little axles are kinda scary.

The carrier is the only thing that is similar between the two axles, as said the 30 is a front and the 35 is a rear.

Lunch box lockers will interchange between the two axles as both are 27 spline and the carriers have the same inside dimensions.

Worth noting is that the carrier itself will not interchange as far as I know.

d35s suck, don't put any money into yours, there are inexpensive ways to dump it rather than polishing a turd. 30 fronts are OK as long as you're nice to them and/or build them right and stick to reasonable tire sizes.

Plus they're from a Yj so the front is a VACD and they're setup for leaf springs. Basically useless.

That's a good point... both SUA leaf spring setup with a different perch width from an XJ.

Parts only, unless you own a welder, and you'd be insane to go to all that trouble for a d30 (and retarded to do it with a d35) instead of pulling one out of the dozen XJs sitting at the local pull a part.

rage_blue said:

I went and bought some used tires and rims from a guy with a yj. When I picked them up he was showing me his jeep and offered me his old stock axles front dana 30 and rear dana 35. I've got a 30 right now in my cherokee. Is it worth puting the 35 in my jeep? Are any of the parts interchangable? I do have plans on chromoly shafts and a detroit locker. whould this handle 33s pretty good?

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The primary difference between the various Dana axles, at their core? Ring gear sizes. As the model number gets bigger, so does the ring gear.

MOST Dana axles can be found in either a front or rear setup, with fronts "dropping" to either side, depending on application. Short listing of CURRENT Dana axles:

Dana 28 - typically found only in IFS under the Ford Ranger or Bronco II
Dana 30 - Typically found in front applications, SLA or IFS.
Dana 35 - Typically found in rear SLA under Jeep vehicles, sometimes SLA or IFS for Explorer front.
Dana 44 - Workhorse axle for light trucks and some cars. Has been found in IFS, IRS, and SLA - common front axle under 1/2 and 3/4-ton trucks or rear axle under 1/2-ton trucks, mid- or full-size SUVs, and some compact trucks.
Dana 50 - Probably 75% of these are IFS, but Ford had them done for front axles under 3/4-ton trucks. Sometimes found under 1/2 and 1-ton trucks - invariably front.
Dana 60/61 - Most commonly rear, some front. Always SLA, to my knowledge. The Dana 61 has a somewhat larger ring gear offset, which allows for "shallower" (numerically lower) ring & pinion ratios, as a boost to fuel economy.
Dana 70 - Largest axle found under the FRONT of light trucks, typically ONLY under 1-ton "heavy-duty" trucks. Beyond that, you're getting into the "heavy" world. Always SLA. Rear versions often full-floating.
Dana 80 - Biggest axle Dana makes for Class 1/2/3 light trucks, always rear (to my knowledge,) always full-floating (to my knowledge.) May convert between SRW/DRW upon availability of parts (outer hubs - although DRW WMS-WMS is rather shorter than SRW.)

NOTES:
- Dana axles may be found in C-clip versions up through the D44 rear. Most through the D44 are semi-float, D60/D70 goes either way (D60 about 50/50, D70 probably about 15/85, between SF and FF.)
- A "C" appended to the model number does not mean "C-clip," it means "custom." This indicates that the axle wasn't supplied as an assembly to the vehicle builder, merely as a housing.

GLOSSARY:
- DRW - Dual Rear Wheels
- IFS - Independent Front Suspension
- IRS - Independent Rear Suspension (not those bastids in Washington, in this context!)
- SLA - Solid Live Axle
- SRW - Single Rear Wheels
- "non-float" - VERY old-style axle, where the inner & outer end of the shaft bore vehicle weight. Obsolescent.
- "semi-float" - The axle shaft bears a portion of the vehicle's weight, typically at the outer end. Lifting the vehicle is necessary to remove the shaft. Shaft retained by action of a bolted plate behind the wheel flange, acting against a pressed-on bearing. Shaft may break without losing the wheel!
- "full-float" - The axle shaft bears no portion of the vehicle's weight, it's done entirely by the housing. A full-float axle shaft may be removed with all four wheels on the ground, by unbolting the outer end and "bashing the shaft loose" (literally - you usually have to smack the drive flange with a BFH to "rebound" it loose!) FF axles are typically found under either 3/4-ton "heavy duty" trucks or 1-ton trucks, and DRWs are invariably run on FF axles.
- C-clip - a variation on a semi-floating axle, where the axle is retained with a C-shaped washer on the inner end of the shaft, within the differential housing, against a "button" machined into ("out of?") the inner shaft end. If this C-clip should come loose and fall out, your wheel can leave. If you snap the shaft in the middle, the wheel WILL leave! (For this reason, C-clip axles are generally not preferred for off-road work!) Many common "C-clip" axles may be retrofitted with "C-clip eliminator kits" (I refer you to Strange Engineering or Moser for more information) where the outer bearing is converted to a press-on. It should be noted that a C-clip axle uses the OD of the shaft as the inner bearing race for the wheel bearing - this makes inspection of the shaft MANDATORY when servicing the bearing!

There are a large number of factors that go into axle strength - the primary ones being:
- Ring Gear Diameter.
- Axle half-shaft OD (thinnest point)
- Inner spline count (more is better, generally, due to the distribution of shear force)
- Axle design (FF > SF > C-clip. A C-clip with an eliminator kit comes close to an SF axle in strength.)
- Materials used (big surprised - better grades of steel result in stronger parts! Use caution - if you do too good of a job improving, say, axle halfshaft strength; you run into having "moved" the weak spot of the axle to - say - the side gears. Or worse, the R&P itself! Then, you're in for a good deal more work when something breaks. Keep your "fuse" easy to fix...)

5-90, You never cease to amaze me with the incredibly detailed information you always have to offer.

I copy/paste/save every bit of your information into a notepad and save it in a "Jeep knowledge" folder. Never know when i'll need it.

5-90....Great post...good info!

A few nitpicks on that otherwise great pile of info:
- I don't think I've ever seen nor heard of a c-clip dana 70, nor a semifloat dana 70.
- c-clip is technically a subset of semifloat axles, not a separate design. The axleshaft is still semifloat either way, just the retention method is different.
- I *think* the e250 rear 60 is a semifloat c-clip rear since people say regular 60 lockers won't fit it or something, but not sure.
- there are some nifty axles that are sorta hybrids from the factory. For example, dana 60-1SUs are smooth housing so they don't catch on rocks as easily, have all 60 parts inside the differential, but are dana 70s from the tubes out - 3.5" tubes instead of 3", larger spindle bearings, spindles already bored large enough for 35 spline axle shafts, etc etc.

I'll use a c-clip axle for offroad without worrying too much under one condition - that it be strong enough to handle the tire size and power being applied. For example a chrysler 8.25 with 29 spline shafts, a ford 8.8, etc. C clips themselves very very very rarely fail, it's more the "if a shaft breaks your wheel is making a run for it" issue. So as long as you spec your shafts properly, you should be fine.

- another few significant design factors that improve axle strength:
-- snout/"pinion span" bearings like the GM 14 bolt has. There is a third pinion support bearing on the snout, so the pinion is spanned by two bearings rather than being cantilevered out past the inner bearing with the outer bearing sorta supporting it. This significantly improves strength by keeping the pinion from flexing, which keeps the mesh pattern under control instead of letting it walk out toward the tips of the teeth. The only reason most smaller axles don't have this is that there simply isn't space for one between the pinion head and the carrier unless the ring gear gets up into the 10-11" range.
-- thrust bearings or thrust bolts like some aftermarket axles have. These are like pinion snout bearings, but support the back of the ring gear flange as it spins so that the ring gear can't flex away from the pinion head. Not as cheap or easy to add since typically there are stiffening ribs and ring gear bolts in the way...
-- higher hypoid offsets result in a stronger axle as this requires more steeply spiraled gear teeth and therefore more teeth are in contact at a time. The tradeoff is that it means more shear forces on the lube, more heat, and more wasted power.

Oh... and here is a helpful table on what the carrier breaks are for a variety of axles, along with the deck heights, useful when trying to determine if a carrier is the one you need.

http://www.differentials.com/technical-help/carrier-breaks

kastein said:

A few nitpicks on that otherwise great pile of info:

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Givvus a break - I was workin' with notes!

kastein said:

- I don't think I've ever seen nor heard of a c-clip dana 70, nor a semifloat dana 70.

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I don't think I've heard of a C-clip D70 either, but I left SF open as a possibility (a slim one, but a possibility.)

kastein said:

- c-clip is technically a subset of semifloat axles, not a separate design. The axleshaft is still semifloat either way, just the retention method is different.

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Correct, but the C shouldn't be considered a "useful" design. The primary failure most for a C-clip seems to be the necked-down section under the "button" where the C-clip goes gets stretched until there's enough room for the C to fall out - then the wheel leaves.

kastein said:

- I *think* the e250 rear 60 is a semifloat c-clip rear since people say regular 60 lockers won't fit it or something, but not sure.
- there are some nifty axles that are sorta hybrids from the factory. For example, dana 60-1SUs are smooth housing so they don't catch on rocks as easily, have all 60 parts inside the differential, but are dana 70s from the tubes out - 3.5" tubes instead of 3", larger spindle bearings, spindles already bored large enough for 35 spline axle shafts, etc etc.

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True on the last - I was trying to keep it simple.

kastein said:

I'll use a c-clip axle for offroad without worrying too much under one condition - that it be strong enough to handle the tire size and power being applied. For example a chrysler 8.25 with 29 spline shafts, a ford 8.8, etc. C clips themselves very very very rarely fail, it's more the "if a shaft breaks your wheel is making a run for it" issue. So as long as you spec your shafts properly, you should be fine.

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As I said, the primary failure mode seems to be the necked-down section under the "button" stretching, which can allow the C to fall out. Then, you're hooped. Me? I'd rather go with a C elim kit, and get that mess right out of the system entirely.

kastein said:

- another few significant design factors that improve axle strength:
-- snout/"pinion span" bearings like the GM 14 bolt has. There is a third pinion support bearing on the snout, so the pinion is spanned by two bearings rather than being cantilevered out past the inner bearing with the outer bearing sorta supporting it. This significantly improves strength by keeping the pinion from flexing, which keeps the mesh pattern under control instead of letting it walk out toward the tips of the teeth. The only reason most smaller axles don't have this is that there simply isn't space for one between the pinion head and the carrier unless the ring gear gets up into the 10-11" range.

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True, because then the side force on the pinion shaft (more or less normal to the axis) is no longer a "lever" - it's pushing BETWEEN two bearings (and the pinion now usually runs on THREE bearings, vice two.) This isn't limited to the 14b SF or FF - the Ford 8" and 9" also ran it, as I recall, and it may have been on the heavier ChryCo axles as well. And, I think AAM uses it on their heavier axles.

kastein said:

-- thrust bearings or thrust bolts like some aftermarket axles have. These are like pinion snout bearings, but support the back of the ring gear flange as it spins so that the ring gear can't flex away from the pinion head. Not as cheap or easy to add since typically there are stiffening ribs and ring gear bolts in the way...

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Fascinating! Examples? I can see how it would be useful, I can also see how there would be a number of things in the way (I'm chewing on a couple of ways to do the job right now, in fact, since you've mentioned it...

kastein said:

-- higher hypoid offsets result in a stronger axle as this requires more steeply spiraled gear teeth and therefore more teeth are in contact at a time. The tradeoff is that it means more shear forces on the lube, more heat, and more wasted power.

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True - which is why the Ford 9" was replaced by the 8.8" - the 9" had a hypoid offset of something like 2.375", while the 8.8" is something like 1.5". This is why the 9" was so strong - but also tended to "use" a lot of power to get moving.

I've been wanting to write a "Basic Axle Primer" for some time, I just haven't gotten 'round to it (too much other stuff going on around here...) But, thanks for catching me - that's why I try to always qualify what I say. I try for accuracy, but can't quite manage Gospel right off-the-cuff...

The only example I can think of off the top of my head is the true high 9 - a high pinion third member and ring/pinion setup for the ford 9" axle. http://truehi9.com/thrustblock2.html

I suppose one could add this kind of setup to a GM 14 bolt or other large axle (possibly Toy axles? haven't been inside those yet) but given the fact that 14 bolts are basically invincible already, I'm not sure I see the point unless you have a hell of a motor or some rather large tires.

5-90 said:

Correct, but the C shouldn't be considered a "useful" design. The primary failure most for a C-clip seems to be the necked-down section under the "button" where the C-clip goes gets stretched until there's enough room for the C to fall out - then the wheel leaves.

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I can't imagine a C-clip falling out but I could be wrong. When I removed the shafts from the C8.25, isn't the point of the center pin in the middle of the carrier designed to keep axleshafts seated outward so the C-clip won't fall out? The only way I can see the axle failing is if it snaps anywhere past the clip neck, or if the center pin falls out and the axleshafts get pushed in, thus unseating the clip. But if the center pin falls out, that'll be just one of the many other issues you'll have. Correct me if I'm wrong.

crimsondragon, you're 100% right and the whole issue is - will the shaft snap at the notch for the c clip?

5-90 thinks it might. I don't, and I've never seen one break there or heard of one breaking there (though I've only been wrenching on jeeps for 4-5 years now.) It'd take an obscene amount of side loading on the wheel to break that (I'm pretty sure the tire would debead, burst, etc well before the c clip button broke off), and there's no torque on that section of the shaft so it certainly won't twist off.

kastein said:

crimsondragon, you're 100% right and the whole issue is - will the shaft snap at the notch for the c clip?

5-90 thinks it might. I don't, and I've never seen one break there or heard of one breaking there (though I've only been wrenching on jeeps for 4-5 years now.) It'd take an obscene amount of side loading on the wheel to break that (I'm pretty sure the tire would debead, burst, etc well before the c clip button broke off), and there's no torque on that section of the shaft so it certainly won't twist off.

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It's the change in material section, coupled with the nice, square profile of the groove that does it. Putting a notch like that in anything is like putting down a dotted line saying "Tear Here." I've had a few shafts handed to me that had had the buttons fracture off - not a torque issue, this was mainly through excessive axial loading of the wheel assembly (pulling the wheel flange AWAY from the vehicle.)

The press-fit for the bearing on the true SF, using the full diameter of the shaft, is still stronger than the reduced section and square-profile groove of the C-clip.

I've been handed three or four halfshafts that have failed (street applications,) and either the neck-down had stretched sufficiently to allow the C-clip to be released from the counterbore in the side gear, or the button had simply torn off of the shaft - both of which resulted in a loose piece of metal or two roaming around in the differential housing, with expected results.

It is worth noting that a magnified examination of the fracture zone did NOT show a torsional failure, it was a straightforward fracture of the material without twisting, merely tensile stress.

I wouldn't say it's common enough to be a BIG problem - but it's not an additional potential failure I'd like to have to worry about on the trail. There's a reason that the big, heavy-duty axles don't have C-clip versions...

Maybe it's not a major issue (it's done primarily for ease of assembly - a cost-cutting measure,) but it entails a few things that I'd really rather not have to think about...