So, you want to wear the big boy pants and run 40-inch meats on your Jeep? When you grow tired of blowing your Dana 60 (so much for “big enough”) and you put a Dana 80 back there, you’ve got a new problem: what about wheels?
If you’ve never seen an 80 with five-lug wheels, well, that’s because there aren’t any – you’ll need eight. What to do about the front axle, then? Feel like cramming a Dana 80 in there too, even if you don’t need it? Nope. Make a set of eight-lug hubs fit the Dana 60.
There are some swap parts that will eight-lug a Dana 60, but they don’t apply to many aftermarket fitments. For a shop dealing with lots of different rigs – some older than others – in crawler-happy San Diego, that’s a problem. After grenading two Dana 60s, the owner of a hard-bitten JK four-door upgraded to a full-float Dana 80 to support his... how shall we put it... indelicate attraction to rocks, and he wanted eight-lug wheels all around. The boys at Off-Road Warehouse in El Cajon decided to decipher an eight-lug option for the JK’s forward Dana 60 so the owner could use 40/13.5/17-inch Pro-Comp XTreme MTRs on eight-lug American Racing 17x9” wheels at all four corners.
The Problem
What you have here is a failure to communicate. Some parts you just can’t reach. It was the parts sandwich of rotor, hub, spindle and caliper/bracket that needed to click together for the Dana 60 on the front of this JK to wear eight-lug wheels, but off the shelf, it didn’t.
There was a lot of testing and retesting necessary to math out what combination of parts is going to work. The brake rotor-to-hub interface needs to: 1. support a rotor that fits over the hub; 2. align with the caliper and bracket assembly; 3. provide proper backspacing for wheel/tire fitment on both the Jeep and with the suspension; 4. it all needs to fit inside the wheel.
Knowing your axles helps. After testing the initial parts combo (when Jeramie Reed from ORW noted the hangup), it was discovered that the Teraflex rotor-to-hub interface was 10mm shy of kosher – the hub’s OD was too large for the Teraflex rotor’s ID. Too beaucoup, as they say.
This JK’s front Dana 60 was a Teraflex kit wearing Spyntech hubs and spindles, which is roughly a Dodge 8-on-6.5” architecture (as was the Dana 80 in the rear). While Teraflex has an eight-lug big-brake and rotor option for new Dana 60s, it doesn’t fit their earlier Teraflex Dana 60 axle/outer knuckle combo, thus the problem. Because the older Teraflex (and Spyntech) parts were going to be a part of this build, the Teraflex eight-lug conversion rotor became the designated square peg.
The Prescription
Jeramie (above), who’s ORW El Cajon’s four-by wrenching impresario, made attempts to use original-equipment rotors from Ford and Dodge (always looking for an off-the shelf combo, if it’s available) to solve the fitment. Though new Ford eight-lug rotors are 8-on-170mm, 1997/older Ford Super-Duty hubs are 8-on-6.5”, like the Dodge architecture that this Dana 60 is based upon. Unfortunately, neither the Dodge nor Ford rotors maintained the alignment necessary to avoid finding/fabricating a new caliper bracket, and the different rotors would either alter caliper and caliper-bracket placement or didn’t fit over the Teraflex outer knuckle. There was no guarantee that this wouldn’t cause wheel fitment issues in turn.
At this point, Jeramie went back to his original plan, which followed his rule of thumb to do as little fabrication as possible. Turning down the OD of the spec Teraflex outer knuckle by 5mm would allow it to fit behind the Teraflex eight-lug rotor. This was an ideal solution, as that rotor already aligned with all the other parts hanging off this Dana 60, and was designed to fit behind the American Racing 17x9” wheels.
“I wish there were off-the-shelf solutions for this sort of thing,” declared Jeramie, “But I don’t think Teraflex wanted to do the R&D on an application that might not sell a lot of parts for them. That’s cool – we can figure it out. It’s what we do.”
The Parts
More than a little product knowledge was required to envision this particular eight-lug swap for the Dana 60, in large part due to the slightly retro application and combination of several manufacturers’ products.
What “ought’a work” is often a short distance from what will, but the shortest path to done might require specialty skills, like a machine shop, or a Ford Super-Duty brake rotor. ORW’s shop was quick to order several factory eight-lug rotors to make the test fit.
Why the Spyntech spindle and hub kit? It’s essentially a Dana 60 hub that converts the unit bearing to a standard (and more durable, and more easily lubed) tapered bearing, while adding a manual hub (again, essentially an old Dodge 2500/3500 hub from 2000-’11). Some parts are worth keeping. Jeramie used Tackett Machine in El Cajon to make the Teraflex axle/outer knuckle fit in the Teraflex rotor, turning down the outer edge of the hub 5mm.
The Process
The actual assembly – once the need for trimming some metal from the hub was deciphered – went together like an axle should. The 35-spline stub shaft went in with fresh hub and axle seals (pretty standard for a heavily thrashed rock bus like this). The caliper bracket and mounting points were given a once-over with an abrasive disc, primarily due to the heavy amounts of grit and surface rust on the mating surfaces. Because the tapered-bearing Spyntech hub is shallower than the unit-bearing hub it replaces, the mounting bolts needed to lose a little of their length.
Copious thread-lock was used when the bolts went in, as well as to keep the spacers in place.
The replacement Spyntech spindle/hub prevented the OE Jeep JK ABS sensor cable from working, so a Dodge 2500 sender and sensor (with the sender snout rotated 90-degrees and a little grinding) were adapted to fit.
Jeramie recommended using the “red sticky” grease on a high-impact application like this Jeep – Winzer’s Big Red – and to pack the bearings as thoroughly as possible. If you pull your truck’s axles apart frequently, a pressure-packer like the one used at ORW makes short work of the process. Also, use the correct tool and correct torque for the locking spindle nuts after the bearings go on.
As this is a creative fitment that didn’t come with instructions, there were many stops for testing fitment – every stop possible, technically. Test wheels, test rotors, test caliper clearance, test brake lines and ABS lines, and test lock-to-lock.
It’s easy to put things together, but like your daddy said about your homework, “Just because all the questions are answered doesn’t mean you’re done. You’re done when it’s right.”
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