I'd like to know more about what rear you're running and the disc brake setup you have.
CK5
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Paging dremu, lets discuss this:
- Thread starter thatK30guy
- Start date
Hey, I know that truck!
Executive summary: SRW 14BFF, with dually wheels, Caddy calipers on custom brackets. ~2003 GMC Express rotors.
Long answer: Oyyy. I'm gonna throw a bunch of info in here so that I don't have to type it again, and to share what I know about swapping SRW and DRW hubs. Prolly more here than you wanted, but someone'll ask and it'll save me retyping
The sixpack started out life as a C/20, so it's SRW. (But, being a sixpack, it's got the narrow spring spacing.)
I converted it to DRW, but I did NOT change the hubs, so it's the same WMS as a stock, SRW 14BFF. Between the tire width (235/85-16's) and the disc stuff, at the narrower WMS there was so little clearance I couldn't get my fingers in, so I kept the SRW hubs. I don't like the aesthetics of the real duallies, i.e. D70 rears, and those giant fiberglass fenders are magnets for fenceposts, and other cars in parking lots. I did tub the wheel wells in maybe 3-4" on each side, and put on some flares I had laying around, but at first glance it passes for an SRW truck. I remember 4x4High did a bit of a double take when he saw it the first time =))
The problem with changing the hubs that everyone ignores is that you then need to move the brake mounting flange. (Unless you can magically find drums and shoes that are exactly 2" shallower or deeper than your old ones!) If you're going from DRW to SRW, i.e. widening the WMS, I s'pose you could use spacers on long bolts to move the backing plate out ... but 2", that's scary! If you're going the other direction, from DRW to SRW, unless the SRW drums and shoes are exactly 2" shallower than the DRW, I don't see reusing that flange. Kert @ DIY4X, btw, can make you a new flange to weld on, but if you're going in, you'll hafta cut the old one off to slide the new one over the axle tube. Been there, done that.
[NB: If I HAD changed the hubs I'd have the narrow WMS of a C&C, 'cuz that's what a C&C is, is a SRW 14BFF with the dually hubs, and the brake flange shifted in.]
While I was in there I figured I'd convert to disc. At the time, nobody sold dually disc kits off the shelf; now I see that Blackbird's does, though they won't tell me what the rotors are from, and TSM lists a set, but they use rotor spacers
So I went through a listing of brake rotors looking for DRW vehicles and found that ca. 2003 Express vans had a dually rear that was close in diameter and mounting, and was thick enough to fit the 3/4-ton front / Caddy rear calipers we know and love.
After some fiddling, which I am not proud of and so will gloss over, I essentially ended up with a custom weld-on bracket kit. The calipers are the usual 76-78 Eldo.
Clearance is TIGHT inside the wheels; I'm using the stock 70's style dually wheels, which are what, 16x7, maybe, but of course crazy deep. The calipers are mounted as close in as they'll go (the advantage of a custom bracket!) and I still had to flapdisc the calipers pretty hard, like you would to put a 15" wheel onto a D60 front. IIRC the rotors could actually be a bit larger in diameter, or the "hat" could be smaller in diameter, which would allow the calipers to go in towards the axle a bit more. That is, it's the hat that's keeping the calipers out so far. (As I'm looking at the picture now I'm thinking I could have trimmed that inside metal lip on the pads
... there comes a point where it's just too much work... and this setup, well, is right about there.)And after all of that, I still ended up needing a bit more clearance on the lateral edges of the calipers, so I had Kert make me some wheel spacers. IIRC, they're 1/4", might be 5/16" or 3/16", I forget. That's the orange on the outside of the hub.
Umm ... that should answer all your questions. Other than the "Would you do it over again?" one you didn't ask =))
-- A
Let me read that again...
Ok, my biggest question is about using that setup on a D70HD.
Where would that put the clearance issues at if this were used on the wide 70?
Would 16.5" wheels clear everything a little better? I'm planning H1 wheels on a wide 70 and want to run disc brakes.
Where would that put the clearance issues at if this were used on the wide 70?
Would 16.5" wheels clear everything a little better? I'm planning H1 wheels on a wide 70 and want to run disc brakes.
thatK30guy said:
I *tole* you it was gonna be long
I *gather* that, spindles out, a D70 is the same as a 14BFF.
The axle width itself won't affect clearance; changing the WMS just shifts all the components (wheels, hubs, rotors, calipers) in or out. The clearance issues are a function of the wheel's distance from the hub (i.e. if there's a spacer involved), and the rotor/caliper.
Honestly, even though they're pricey, I'd get a kit, unless you can find someone who can identify the rotors used in the kits and get them separate. There just isn't the wealth of info on do-it-yourself dually disc conversions the way there is for the SRW axles.
I wouldn't recommend the Express rotors unless you absolutely can't find anything else, as they aren't sized quite right, and you'd still have to weld on the caliper brackets, which is just messy.
I would guess that H1 wheels are not as deep as dually wheels; the WMS on the dually wheel is actually OUTSIDE the tire lip, right, versus the HMMWV WMS is close to the lip, but on the inside, IIRC.
Point being that by virtue of that and theslightly larger size, you should be fine. But I'd still get a kit
-- A
Yuck. Blackbirds wants $580 for their D70 kit without calipers.
http://www.blackbirdscustomtrucks.com/index7.html#8dually
As you said, I would also like to know what rotors they use in this kit.
http://www.blackbirdscustomtrucks.com/index7.html#8dually
As you said, I would also like to know what rotors they use in this kit.
They won't tell you -- at least, they wouldn't tell me, and I actually bought one of their kits in the past.
And yeah, TSM gets $600 for theirs.
Anybody got a really good book of rotors and dimensions?
I still have my notes somewhere...-- A
lectric80
3/4 ton status
Thanks for that link, I wonder if I can clear 15" wheels with their kit for the 14ff? If I can, I can see another upgrade in my future before I swap in the 14.
You do know that DIY4X sells a disc conversion kit for the d70HD? It does clear H1 wheels
