Proper backspacing for Method Racing 305 wheels

[Yeller]

Bronco BP to bronco BP means your not changing bolt pattern.

 

[tommyg]

Bronco BP to bronco BP means your not changing bolt pattern.

ahh...makes total sense. Thanks!

 

[Yeller]

ahh...makes total sense. Thanks!

I should have elaborated…. They make those to change bolt pattern as well. Go from 5x5.5 to 5x5, 5x4-3/4, 5x4-1/2. Rarely do you see them change lug count from 5 to 6 or 5 to 8, there are lugs competing for space.

 

[TX73Bronco]

Love to know what you ended up going with for spacers. I am getting the method 305s also for my 73.

 

[Shimmy]

Thanks for the recommendation...sorry if it's a dumb question, but what does bronco bp to bronco bp mean? I checked out the website and it looks as though they are very customizable down to the exact mm. Can you share what size you are using? I suppose the best would be to try on the wheels first and decide from there. These are the specs I took for the NV wheels...

i ordered 38mm spacers ~1.5"

when bora makes yours spacers they'll come with a wheel centric lip to fit perfectly in the 108mm bore of the method wheels. this is important because now the spacer studs aren't relying solely on they own shear strength to hold the wheel in place.

 

[jamesroney]

One of the other members posted up a site a while back that offers all sorts of wheel adapters, not wheel spacers. Similar but technically different. Might have been @jamesroney or @Yeller
Try searching for wheel adapters, even if keeping the same bolt pattern, I think wheel adapters are what you're after.

Sorry for the late reply. But any time I see the topic of wheel spacers...I usually run away screaming with my fingers in my ears.

Mostly because I always end up hurting someone's feelings...so don't take it personal.

The industry has adapted the name of "wheel adapter" versus "wheel spacer" as a means to differentiate between the two methods of spacing out the wheels. It's just a name. You could have just as easily called the first type "Fred" and the second type "Barney." As long as everybody understands that "Fred" goes with "Wilma" (...and Barney goes with Betty), then it all makes sense, and everybody is happy. Of course the first guy that comes along who never watched the Flintstones thinks you are all a bunch of idiots.

For many years, back in the 1970's I used to despise wheel spacers. Wheel spacers combined with uni-lug ET mags resulted in all kinds of bad things. Oddball mixed depth shank lugs, pulled threads, busted studs, wobbled out holes...just ugly. About 30 years ago, somebody invented the low cost CNC machining center, and started making lug pattern adapters out of 6061T6 aluminum, with machined conical seats, lug centric, and with an additional set of press in studs to allow the use of GM wheels on Ford cars. (solving the infamous 5x4.5 vs 5x4.75 argument) This changed everything. 5 lug Wheel adapters could be mounted properly, secured, and they were awesome. But they could only be made about 1-1/4 inch thick. Steel adapters could be made thinner, but you would have to use shorter lug nuts, and cut off the excess studs. (and pay more money) But whatever. Great solution to let you swap around your GM / Mopar / AMC / Ford wheels around. I don't know how many tires were destroyed by fenders in the 80's. But it was a lot.

But what if you wanted to use that same safe, reliable, economical and available solution as a wheel spacer? Easy enough. You can go from 5x5.5 to the same pattern 5x5.5 and as long as you need at least 1.25 inches of thickness...you can buy the wheel adapter. (yeah, we all know it doesn't adapt anything to anything, and it's really just a spacer. But unless you want a giant washer with 5 holes drilled in it, and 3 inch long lug studs...let's just agree to name it a wheel adapter.) Sometime in about 2007, some genius at Daimler Chrysler thought it would be a good idea to change the back spacing and bolt pattern of the Jeep Wrangler from 5x4.5 to 5x5 and increased the backspace from 4.5 to 6.25 inch. This puts the wheel hub and king pin inside the wheel, and solves lots of cost-cutting initiatives. So if you want to jun Jeep JK wheels on your older TJ or YJ...you just need a wheel adapter. There's probably more of those spacers now than Jeeps.

Along about 1988, the same chassis engineers that put IFS on the front of the GM K2500 figured out that there is an upper limit to the amount of weight that can be carried by a single 235/85/R16 tire. And that amount of weight didn't change if you put an emblem on the side of the truck that said "2500" or "3500." (It took Ford almost 9 more years to figure that out...) Sure, you could put a lot more weight on the BACK of the truck, but the front axle had the same GVW between the 3/4 ton and the 1 Ton. But those pesky Dual rear wheels used a different offset. And we only want one spare tire. So...the "factory" wheel adapter was born. The 1 ton IFS Chevy uses all 3/4 ton outers, with a bolt on wheel adapter. (and enormous brakes!) It's like the GM engineers were handed a JC Whitney catalog from the 70's. But whatever. It PROVED that wheel adapters were safe, effective, durable, and could be used on the front of heavy duty 4x4 applications in pickup trucks. (those same morons put IFS on the 6G Bronco, thus ensuring that Jeep will dominate the off-road market.)

Anyway, back to Broncos and the OP. @tommyg why do we think that the 57.5 inch wide WMS on a Bronco 9 inch rear axle is the same as the 60 inch WMS of the front dana 44 axle? My math says it's about 2.5 inches narrower. I spend a lot of time building custom rear axles for Early Broncos where I add 2 inches to the rear to match the front. So I'm puzzled about what you have. There's a lot of guys that run custom 31 spline axles and Explorer rear disc in their older 9 inch with a 2.5 brake offset...so they can pick up an extra 1/2 inch or so. But I don't know your configuration. But the factory widths are different front vs rear.

Gotta run...

 

[toddz69]

Anyway, back to Broncos and the OP. @tommyg why do we think that the 58 inch wide WMS on a Bronco 9 inch rear axle is the same as the 60.5 inch WMS of the front dana 44 axle? My math says it's about 2.5 inches narrower. I spend a lot of time building custom rear axles for Early Broncos where I add 2 inches to the rear to match the front. So I'm puzzled about what you have. There's a lot of guys that run custom 31 spline axles and Explorer rear disc in their older 9 inch with a 2.5 brake offset...so they can pick up an extra inch or so. But I don't know your configuration. But the factory widths are different front vs rear.

Gotta run...

Wait....so the Ford factory spec of EB 57.4" track width front and rear (with identical wheels and tires) has been a lie for 58 years?

Todd Z.

 

[jamesroney]

So the Ford factory spec of EB 57.4" track width front and rear (with identical wheels and tires) has been a lie for 58 years?

Todd Z.

Nope, not a lie. Just an error. A lie is an attempt to deceive. I see no deception here.

Might be correct for a drum brake D30? I don't know. I only know what my tape measure tells me on the disc brake 44, and the big bearing 9 inch.

I'll go take some measurements now, just to be 100%.

 

[toddz69]

Nope, not a lie. Just an error. A lie is an attempt to deceive. I see no deception here.

Might be correct for a drum brake D30? I don't know. I only know what my tape measure tells me on the disc brake 44, and the big bearing 9 inch.

I'll go take some measurements now, just to be 100%.

Very interesting - didn't know that detail. The K5 Blazers are about 2" wider in the front too, right?

Todd Z.

 

[jamesroney]

Very interesting - didn't know that detail. The K5 Blazers are about 2" wider in the front too, right?

Todd Z.

These pics are 5 minutes old. Best I can measure. Rear is a big bearing 9 inch from a 1970 Sport. 57-3/4 inch with drums. Maybe 57-5/8 without.
This Dana 44 has GM spindles with Bronco hubs and rotors. 60 inch.

I'm going to say that the Dana 30 is the same width as the D44, since it uses longer length inner axles (total of 46.5 versus 46.25) , and identical stubs. (9-23/32) (The extra 1/4 inch is at the carrier cross pin.)

Brake drums mess things up a little, because the factory ones are pretty thick, and outboard of the wheel flange. So they get added to the WMS. It is worth pointing out that the industry has adopted the WMS to *sometimes* ignore the thickness of the brake rotor hat or drum. So the WMS is measured to the axle flange face, which is NOT the Wheel Mounting Surface. (since the Wheel doesn't seat on the axle flange.) For the purpose of determining whether your front dana 44 is from an F150 or a Bronco, or trying to figure out which GM 14 bolt full float SRW axle you have it is an adequate reference. When you are specifying custom axles for your 35 spline 9 inch...WMS is worse than useless.

I want to say that the factory drum brake Dana 44 Early Bronco WMS sits right at 60.5. I don't know WHY I think that, but It's stuck in my head. Someday I will measure one again.

Yes, the K5 blazer, and pretty much any wide frame, leaf sprung live front axle is wider in the front. Everybody thinks its for stability, or traction. But its basically to improve turning radius. It allows you to get a better steering angle. Anyone that has ever made a u-turn in an 86-97 F350 crew cab 4x4 knows this. The 1993+ GM K2500 Suburban with IFS is also about 71 WMS up front, and 67 WMS in the rear. You need 2 inch wheel adapters "fix" it. My 1953 Willys Pickup had very narrow frame up front, and a narrow track up front. Also a very wide rear track. So it's all over the place.

 

[toddz69]

Very interesting! Thanks for taking the time and effort to get those measurements. Andrew has told me the GM disc conversion does add some width to WMS measurements but it was not in the neighborhood of 2.5".

Todd Z.

 

[TX-ZACH]

I have been running these spacers for a few months now. Super happy with this 2" and top quality. https://www.amazon.com/gp/product/B07VCL13C9/?tag=classicbroncos-20

 

[ksagis]

Okay, I have to bite since this has been something I’ve been curious about. Gonna start a new thread instead of hijacking OPs thread.

(My rigs has Chevy brakes in front and Caddy brakes in back and has front WMS 59.75” and rear WMS 58.06”. Which is why I had posted to OP that brake mods can play into this equation. I had always attributed my WMS difference to brakes mods as a result of reading the same Ford literature as Todd mentioned.)

@tommyg, did TireRack drop off your early Xmas gift?

 

[Shimmy]

I have been running these spacers for a few months now. Super happy with this 2" and top quality. https://www.amazon.com/gp/product/B07VCL13C9/?tag=classicbroncos-20

lots of these on the market and i can't recommend this design. any spacer (certainly an adapter style) over 12mm should have a wheel centric lip. that is a lot of torque/load placed on just the bolts alone.

you may have luck running these but this is the type of spacer associated with wheels falling off and what gave spacers a bad rap in general. you also have the risk of potential vibrations of the wheels aren't torqued properly.

again, this may work for you but there are safer designed spacers on the market.

 

[jamesroney]

Very interesting! Thanks for taking the time and effort to get those measurements. Andrew has told me the GM disc conversion does add some width to WMS measurements but it was not in the neighborhood of 2.5".

Todd Z.

I am inclined to agree with Andrew, but the difference would be much closer to 0.2 inches. The difference in the outer stubs between GM and Ford is 9-15/16 vs 9-23/32 = 0.22 inch. Since the GM brake conversion uses the Ford Hub and Rotor it makes sense...because you can't fit the outer snap ring on the hub when you pair Ford stubs with GM spindles. It ends up about 0.2 short. So I'm going to say that the GM disc brake conversion is 0.22 inches wider per side than the Factory Ford one. I'm going to guess that it is pretty similar to the Drum Brake 44 since the cast iron drums are about 1/4 inch thick.

I could measure them against my stock U13 D30 front drums, but I'd have to pull a wheel. And I'm a little bit lazy. Besides, @ksagis started another thread, and that might be a better place to post the numbers.

 

[TX-ZACH]

lots of these on the market and i can't recommend this design. any spacer (certainly an adapter style) over 12mm should have a wheel centric lip. that is a lot of torque/load placed on just the bolts alone.

you may have luck running these but this is the type of spacer associated with wheels falling off and what gave spacers a bad rap in general. you also have the risk of potential vibrations of the wheels aren't torqued properly.

again, this may work for you but there are safer designed spacers on the market.

Question.. Are you the same guy on the FB groups barking at people for putting hood scoops on?

 

[toddz69]

Question.. Are you the same guy on the FB groups barking at people for putting hood scoops on?

No, that's @Dickie. He does the same thing in the BaT auctions.

Todd Z.

 

[Shimmy]

Question.. Are you the same guy on the FB groups barking at people for putting hood scoops on?

definitely not me.

regarding spacers, folks can run whatever they want. i'm just giving my 2cents and have experience with both types of spacers. you get what you pay for in that arena.
in your case, make sure you check on those periodically.

 

[tommyg]

Halfway through, haven't tested for rubbing yet but either way planning to get spacers. Definitely happy with the look of the new setup versus old...although if you like the old setup hit me up as they'll soon be for sale

 

[tommyg]

i ordered 38mm spacers ~1.5"

when bora makes yours spacers they'll come with a wheel centric lip to fit perfectly in the 108mm bore of the method wheels. this is important because now the spacer studs aren't relying solely on they own shear strength to hold the wheel in place.

Very helpful, thank you. I'll likely go with something closer to 1".