Does anyone know the dimensions for the center hub on the Dr Diff 5 x 4.5" axles? I was thinking about removing my spacers on the back of my Dart and noticed that my wheels don't sit flush on the flanges. They sit flush on my 1/4" spacers though! I am getting offset shackles installed and was hoping I could get more clearance from the fenders by removing the spacers. So, it seems like my options are to bore out my wheels or buy new wheels. Has anyone had problems with Enkei wheels as I like those too? Thanks for your help.
Dr Diff Axles and Wheel Centerbores
- Thread starter MuuMuu101
- Start date
-
I can pull the Dr diff axle register dimensions off my Dart tomorrow, I don't recall them being any bigger than the stock BBP axle register though.
The enkei center bores are usually 73.1mm, but they do have some wheels that are smaller. If they're not clearing the register on the rear axles yours might be smaller.
They center bores of the enkei's also taper down to a smaller wheel cap. I needed to have my enkei rpf1's bored out to fit on the front of my Duster. The 73mm is big enough, but since the disk hub goes completely through the center bore of the wheels I needed them to be 73mm all the way through, not half way and then taper down to the cap. Wasn't a big deal though, I think it was $40 a wheel to have them through-bored to 73mm and then I just had to come up with my own wheel cap.
The enkei center bores are usually 73.1mm, but they do have some wheels that are smaller. If they're not clearing the register on the rear axles yours might be smaller.
They center bores of the enkei's also taper down to a smaller wheel cap. I needed to have my enkei rpf1's bored out to fit on the front of my Duster. The 73mm is big enough, but since the disk hub goes completely through the center bore of the wheels I needed them to be 73mm all the way through, not half way and then taper down to the cap. Wasn't a big deal though, I think it was $40 a wheel to have them through-bored to 73mm and then I just had to come up with my own wheel cap.
The PF01, which I'm thinking about getting, has a 75mm center bore. Did you have that problem with the Dr Diff hubs up front? I thought those were Mustang patterns? My centerbore on my Mickey Thompson wheels are about 70mm. I don't care too much for a wheel cap too much.
https://www.summitracing.com/int/parts/enk-4608956635sp/overview/
https://www.summitracing.com/int/parts/enk-4608956635sp/overview/
69_340_GTS
Well-Known Member
Yeah the dr. diff front hubs have a 2.7" diameter. That's only like 68.5mm so it's smaller than the stock hubs but the issue is that the RPF1 center bore starts at 73mm but then tapers down to 64mm at the wheel cap. The problem is that the RPF1's are thinner at the mounting point than the hub is deep, so the hub has to pass completely through the wheel. So I needed to have the bores opened still.
Not sure about the PF01's, but just because the center bore starts at 75mm doesn't mean the wheel cap is 75mm. It shouldn't be an issue for the rears, but it might still be an issue in the front depending on how thick the rim is at the mounting surface and how deep the hub is.
I'll get the rear register measurement here shortly.
Duh. You know if I'd thought about it for like 2 seconds I would have realized that the register on the Dr. Diff axles can't be any larger in diameter than stock because the stock drums wouldn't fit. 
Anyway, the Dr. Diff 8 3/4 BBP axles have a center register of like 2.795", and it's about .5" tall. The stock BBP 8 3/4 axles actually have a register of ~2.825, and it's a little shorter at .48".
So the stock center register on the rear axles is like 71.7mm, the Dr. Diff register is like 71mm.
For the fronts, if I didn't explain it well enough here's a picture that shows what I'm talking about with the hub coming all the way through the rim
And here you can kind of see the machining on the centerbore I did compared to the original
Anyway, the Dr. Diff 8 3/4 BBP axles have a center register of like 2.795", and it's about .5" tall. The stock BBP 8 3/4 axles actually have a register of ~2.825, and it's a little shorter at .48".
So the stock center register on the rear axles is like 71.7mm, the Dr. Diff register is like 71mm.
For the fronts, if I didn't explain it well enough here's a picture that shows what I'm talking about with the hub coming all the way through the rim
And here you can kind of see the machining on the centerbore I did compared to the original
That's perfect to know. The PF01 in the rears seem like they'll fit fine. The centerbore of my current wheels are just 1 mm in diameter too small for the bbp axles , so that explains why they're not sitting right. The fronts with the PF01 may work out. If anything, I think I can get away with the taper if I just use the +5mm spacers I have.
-
