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Nuts & Bolts - Which Front Locker Fits This Ford?

Trenton McGeeWriterTrenton McGeePhotographer

Exploring Lockers
I have a 2001 Ford Explorer Sport two-door. I bought this vehicle 10 years ago to just have a nice SUV that could do some minor four-wheeling, but today it has morphed into a fairly decent off-road machine.

I have problems finding anything for the Ford. It seems that nobody makes anything for it. I wanted to have a bit more safety in traction. I thought an easy solution would be to put a locker in the front. I already have a PowerTrax in the rear 8.8, but this is where it really gets murky. My 4Wheel Parts ordered an Eaton E-Locker for it, but it would not fit. Then I bought an Aussie Locker for the Dana 35 IFS, which is what I’m supposed to have. I had my mechanic do the swap with the caveat that if it didn’t fit it was my buck and not his. So I’m out $500 because that didn’t fit either.

Aussie Locker then informed me that my Ford could have two possible front diffs, the Dana 35 and a Dana “Super” 30. I can find no info on the Super 30. Is it a good differential? Apparently the Dana 30 is used in Jeeps, but there it’s a solid axle. One of the local driveline shops told me that if I had the Dana 30 that nothing would fit in it. Is it possible to swap out the Dana 30 for a Dana 35, and as long as I’m going there how about a Dana 44 IFS?
Al M.
Via nuts@4wheeloffroad.com

Like you, we found a lot of contradictory information about the axle in your Explorer, even among industry experts. Virtually all of the internet forums were completely wrong. In the end it was a Spicer application manual that helped clear the air. Special thanks to our buddies at Motive Gear (motivegear.com) and PowerTrax (powertrax.com) for helping us compile some of the following information.

Much of the confusion out there stems from the (false) assumption that Explorers, Rangers, and Sport Tracs were all equipped the same way. This is not the case. Your 2001 Explorer should have a Super Dana 30 (also called a Dana 30 IFS or a Dana 30CS) front differential and not a Dana 35. According to Spicer BOMs, the 2001, 2006, and 2007 Explorers should be equipped with a Super Dana 30, while 1999 and 2002-2008 Explorers should have Dana 35s. Meanwhile Rangers, which share the same basic front suspension design as your Explorer, should have had the Dana 35 from 1999 until 2008 (though there appears to be a hole for 2000 model year applications). Your particular application adds to the confusion because second-generation two-door Explorers only continued until 2003, while four-door models switched to the third generation in 2002. Why Ford switched from the Dana 35 to the Super Dana 30 and back (and then back again) is anyone’s guess, but the Spicer application guides were the most definitive sources of information we could find. This information would also explain why you’ve attempted to have two different Dana 35 differentials installed and they didn’t fit.

There are two ways to verify which axle is under your Explorer. The first and best method is to find the BOM tag located on the passenger-side axletube. You are looking for a seven-digit number with the last number separated by a dash (e.g., 610833-2). This number will properly identify which axle you have and lead you to its gear ratio and all of its service parts (bearings, differential cases, and so on) if you look up the BOM on Spicer’s website. The second is to look at the differential cover, as a Super Dana 30 and a Dana 35 cover are distinctly different. The Dana 30 cover will be retained by 10 bolts, while the IFS Dana 35 is retained by 12.

At any rate, all of the available information points to your Explorer having a Super Dana 30. Dana 30s and Dana 35s have been used for many, many years under Jeeps, so there is a lot of aftermarket support for the axle when it comes to ring-and-pinions. It is important to note that Super 30s have more in common with the front axles in JK Wranglers and WJ Grand Cherokees than the older CJ versions. There are some variations in the bearings used with both types of IFS axles, so be careful when ordering. This is another reason why it’s handy to have the BOM number from the axle.

As for adding a traction device, there was more conflicting information. While “normal” Dana 30s and Dana 35s have a wide range of options, on paper very few of them will work with your axle. The issue stems from how the axleshafts are retained in an IFS application as opposed to a live axle. The shafts in IFS applications use an internal snap ring (sometimes called a cir-clip) that compresses when the shaft slides through the side gear and then expands once it passes through the gear to hold the shaft in place. Live axleshafts are retained externally, outside of the differential, or they use C-clips that are very different from snap rings. In most IFS cases the side gear needs to have a groove machined in it in order to accept this snap ring, otherwise the axleshaft could slide right back out of the housing. Because of this difference, most of the traction devices available should not work in your Explorer’s axle. PowerTrax lists a Lock-Right specifically for the IFS Dana 35, while Aussie Locker (aussielocker.com) lists applications for both the Dana 35 and the Super 30 axles. Both of these are drop-in style lockers that reuse the differential case, and presumably they have provisions for retaining the axleshaft. Eaton (eaton.com) lists a Detroit Locker and an E-Locker for the IFS Dana 35 only, but Randy’s Ring & Pinion (ringpinion.com) claims that a Detroit Locker, E-Locker, and several other lockers will work in an IFS Super Dana 30 even though the different manufacturer application guides say otherwise. We even called Randy’s and asked to make sure the website was correct, as Randy’s site was the only ones that lists lockers other than the Aussie to fit an IFS Super Dana 30. We would lean toward trusting the locker manufacturer’s information over a distributor’s, but it’s ultimately your call.

Some people have reported successfully installing a few different driver-selectable lockers in both axles despite manufacturer literature, and this could be because IFS applications don’t introduce much axleshaft plunge (in-and-out movement) as the suspension cycles. And there’s always the option of having the side gears in a normal Dana 30 or Dana 35 traction device machined to accept the snap rings. Nevertheless, we would want to be absolutely sure that the shafts are being retained properly as it would suck to find out they aren’t when you’re out in the middle of nowhere by yourself.

As for swapping the differential, yes, you could swap the Dana 30 front differential assembly that you have for a Dana 35 IFS from a similar year Explorer or Ranger, and it should bolt right in. Some of the known weaknesses of the live-axle version of the Dana 35 don’t really apply to the IFS versions, and the ring gear of a Dana 35 is actually a little bit bigger than a Dana 30. In the end, though, you may want to examine just how badly you want a locker in the front of your Explorer, as a locker is going to place a lot more stress on other marginal components, like the CV shafts.