So to match up front, I'm doing a 5 lug conversion up front so i can smack some z32 rotors and calipers on there as well. I feel like I've made enough progress on it that it's worth its own thread. My thinking was that I could either find a car with 5-lug hubs with the same bearing inner diameters to where it would slip right on to the Roadsters spindle with no or very minor modifications to the spindle. Or, I could find a hub with the same bearing outer diameters and just use the roadster bearings. After hours and hours of researching hubs, bearing diameters, bearing widths and so on, I came up with zero solutions that didn't require any machine work. The closest thing I found was some z31(first generation 300zx) hubs. The bearing outer diameters were within like 2mm of each other.
Apparently there are 3 different types of Z31 hubs. The '84s and '85s had a 4x114.3 pattern, The 86-89 N/A cars had 5x114.3 pattern with a 'bolt-on' brake rotor, and finally the 87-89 turbo cars had the 5x114.3 pattern with a 'slip-on' brake rotor. When Nissan went to the Z32, they ditched the tapered bearings and went to a roller bearing. The 87-89 turbo front hubs are very desirable, as they are a very simple swap to the s30 and s130 chassis allowing a z32 brake upgrade. Therefore, they are hard to find... therefore they are expensive. After many unsuccessful junkyard trips, I found a guy on craigslist in California who was parting out an 87 turbo. A quick phone call and $200 bucks had these hubs removed, cleaned, packed, and shipped...SCORE!
I banged the z31's bearings and seals out and tossed 'em. There was a machinist in the area that has done some work for me in the past, so I took the hubs and the outer Roadster bearing races to him, and had him bore the hubs out to fit the bearings. The 300zx's bearing seal fits over the outside of the hub, so this surface is machined concentric to the bearings (first photo below). He used this surface to mount it in the lathe. After boring the outer bearing diameter, he machined a little lip on the outside of the hub (second photo below) in order to mount that surface in the lathe in to bore the inner bearing diameter. Smart
This cost me $80 but i gave him $100 because i was so freaking happy he did such a good job.
Immediately after getting back, I knocked put the wheel bearings in. Heat the hubs with a propane torch, bearings in the freezer... they tapped right in. Before going down this road, I really studied pictures of both the z31 and roadster spindles, took measurements of the z31 hub and roadster spindle, and was really hoping this would work. When I fit the hub on the spindle, there was about 3/16" (.1875") of play.The spindle was too long, so when tightening the spindle nut, the outer wheel bearing would hit the start of the spindle taper before allowing the bearings to seat properly.
My 3 options were to either space the inner bearing, space the outer bearing, or machine the spindle (hell no). If I spaced the inner bearing, it would push the hub outwards. This seemed like it might push it out too far, and not allow the wheel seal to properly contact the shoulder of the spindle, so I decided to space out the outer bearing. I wanted a quick fix, so instead of fabricating a spacer, I checked out what McMaster-Carr had for an oddball size washer. McMaster>Washers>Sort outer diameter:1.850" Boom, done! McMaster part number 91074A140. This is a Nordlock NL30 washer for 1-1/8"(30mm) bolts. $20 bucks shipped for 2 sets. These things are a 2 part lock washer, the outer diameter is within 0.002" of the roadster wheel bearing, the inner diameter clears the roadster spindle, and when put together, had a thickness of .223 (a tad bit more than I needed, but not too much). I superglued the set together so they wouldn't rotate around and change thickness when hammering in the bearing, and fit them into the hub. One set just barely dropped in, but the hub was still HOT from hammering out the bearing. The other hub had been sitting, and was just warm, so it needed to be heated up again to get the washers and bearing back in.
I gave the hubs a couple coats of VHT 'cast iron' color spray paint, and smacked in the wheel seals $25. Because the wheel seals on the stock roadster hub are pressed into the same part as the wheel bearing, the stock roadster press in to the modified Z31 hub. Okay! Moment of truth!.....They FIT! The spindle nut can now be tightened, seating the bearings properly, the wheel seal sits right where it should on the shoulder of the spindle, and the existing cotter pin hole can be used for the castle nut. I lost them, but the dust caps can pop into the hub as well.
There it is, 5-lug hubs on a Roadster spindle. In summation, $200 for hubs from an 87-89 300zx turbo, $100 for machine work, $20 for washers, $25 for seals. I'm sure this can all be had/done for about $150 less, but I'm in it $345.
I picked up a set of 30mm aluminum Z32 calipers for $200 and drilled slotted rotors for $100. I will soon start designing the bracket to mount the z32 calipers to the roadster spindle, and estimate the fabrication to be about $100 for waterjet services. Including some nice brake lines and pads, I'm looking at about $900 for the 5-lug swap, with aluminum 4-piston brakes. I will keep y'all updated on how the brakes turn out, but feel free to check out my progress on the entire build over in the members ride section.
Cheers,
Wade
I just had never thought of using the NA hubs and brakes. Definitely more bang for the buck for sure!