3/4 ton to dually conversion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Tx Firefighter · 10-06-2004, 08:38 PM

I'd like to hear from guys that have swapped 3/4 tons over to dual wheels.

I know in the rear, you can just put the dual wheels on a single wheel truck. Do you have to change wheel studs?

Didn't dually wheels change sometime to larger wheel stud holes?

In the front, I've read the spindles are the same. Are the rotors the same too, or different? I know Dodge trucks use a spacer deal that bolts onto the 3/4 ton front rotor to space the wheel out further so a dually offset wheel will work. But after unbolting the spacer, the rotor is the same 3/4 to 1 ton. Is GM like this too?

1969 GMC · 10-06-2004, 08:41 PM

GM does use a spacer but IDK if the rotor is the same. Should be, but not sure. It is this way on 2 and 4 wheel drive trucks.

Robert1970C20rstbukt · 10-06-2004, 09:25 PM

I wanted to do this too, but my truck has drums in the front. I'd have to swap 'em to discs right?

Longhorn Man · 10-06-2004, 09:42 PM

The drum beake dualies had different drums. Kinda hard to explain...but it had the section that spaces it out all as one piece. not just a spacer.

Robert1970C20rstbukt · 10-06-2004, 09:53 PM

Damn, I figured it would work out that way. I have all the stuff to swap over to disc brakes, so the dually wheels should just bolt right onto those right?

Tx Firefighter · 10-06-2004, 09:56 PM

That's what I'm trying to find out.

I did a search and it seems that the 3/4 ton spindles and calipers are the same as 1 ton. I can't determine if the dually uses a huge offset rotor, or if it uses a 3/4 rotor with a big spacer hub bolted to it.

I have a 72 3/4 ton disc brake truck to use at least the spindles and calipers, it's the rotors I need to know about.

*1972C10* · 10-06-2004, 10:25 PM

Its really simple Beat longer studs in the rear and put dookie rotors on the front. I converted one over a few years back.

1969 GMC · 10-06-2004, 10:27 PM

Quote:

Originally Posted by 1972C10

Its really simple Beat longer studs in the rear and put dookie rotors on the front. I converted one over a few years back.

dookie rotors?

the stock studs may be long enough too.

*1972C10* · 10-06-2004, 10:35 PM

Yeah man around these parts we call duallys dookies. You cant put the plate on outside of the wheel with stock studs.

72 CustomCamper · 10-06-2004, 10:44 PM

Hey Tx Firefighter, it's a shame that you're half was across the US. I have everything here in Va that you would need to do the swap. I have a 78 dually that I parted out. Still have the drive train...

Chuck

Tx Firefighter · 10-06-2004, 10:53 PM

Quote:

Originally Posted by 72 CustomCamper

Hey Tx Firefighter, it's a shame that you're half was across the US. I have everything here in Va that you would need to do the swap. I have a 78 dually that I parted out. Still have the drive train...

Chuck

You have front rotors?

I can imagine they would cost as much to ship here as new ones would cost at the parts store. I've not lifted any in a few years, but I seem to remember them being very heavy.

68w/sbc406 · 10-06-2004, 10:59 PM

i just paid 21 bucks to have some shipped from ECE wherever they are located to portland or. 2WD
EDIT: they are in fresno California

72 CustomCamper · 10-06-2004, 11:06 PM

Yeah, still have the front cross member attached to the frame too. It's still sitting on the tires for the moment...

Chuck

**kwmech** · 10-06-2004, 11:08 PM

I am speaking of factory parts here--- the spindles are different between the 3/4 and 1 ton. The dually spindle takes a different caliper for a wider[thicker] rotor and thus needs the 1 ton dually spindle for the caliper mount. They do however use the same bearings and seals, ball joints also [ if i remember right ]

longhorn71 · 10-06-2004, 11:18 PM

I tried to put dual wheels on a 3/4 t rear end but the drums are different and would not allow the inside wheel to slide over the drum with a 16 " wheel. With the factory 18"wheels they were big enough to go around the drum but the tires are not made for those rims anymore. The brake drums on the factory dual wheel trucks have a longer cone shape to them.If you need a pic of the brake drum, I have one from 3/4t and a 1t. The one ton axle housing is narrower on the 1 t because of them having inboard brakes.

Tx Firefighter · 10-06-2004, 11:22 PM

Please post what pics you have.

I did a search here and some guys said they would just slide onto the 3/4 ton rear.

The search also said the spindles were the same too.

I don't know what to think.

longhorn71 · 10-06-2004, 11:29 PM

Quote:

Originally Posted by Robert1970C20rstbukt

I wanted to do this too, but my truck has drums in the front. I'd have to swap 'em to discs right?

No, you do not have to swap to discs. The 1t has the same brake drums as the 3/4t but has a spacer either riveted or bolted to it. To compinsate for the offset of the 1t wheel, but the disc brakes are safer and provide more stopping force.

Robert1970C20rstbukt · 10-06-2004, 11:53 PM

Ok thanks for the info. So I just need to get some front spacers right?

longhorn71 · 10-07-2004, 12:04 AM

Quote:

Originally Posted by Robert1970C20rstbukt

Ok thanks for the info. So I just need to get some front spacers right?

I think so. I have a set of spacers but I need to look at it in the morning . I posted some pictures of My Own Junkyard.the truck was in one of those pictures.It is a 67 GMC 1t(blue).

longhorn71 · 10-07-2004, 12:06 AM

Quote:

Originally Posted by Tx Firefighter

Please post what pics you have.

I did a search here and some guys said they would just slide onto the 3/4 ton rear.

The search also said the spindles were the same too.

I don't know what to think.

I'll post one tomorrow as it is too dark to take pictures right now.

**JIMs70GMC** · 10-07-2004, 05:13 AM

I'll see if I can get pics of the 72 C30 I'm going to buy. Where can you buy dually rims? and could someone explain the terminology.

matt67350 · 10-07-2004, 09:10 AM

I need to take the wheels off the 72, you can get a good look at the rotors then.

mcmlxix · 10-07-2004, 10:52 AM

I just drove home a 72 C/30 Dually with camper. I'll see if I can get some pics today as well...

**PICKMUP** · 10-07-2004, 12:37 PM

This is a 72 3/4T Dana 60 rear that is converted to duals. It running in the truck when I got it. Appears to have added: big studs & lugs and a spacer.

Robert1970C20rstbukt · 10-07-2004, 06:45 PM

Yep, those studs and the lugs are way bigger that the ones on my truck. The drum almost looks the same though.

Longhorn71,

OK, I saw that blue 1 ton truck that you told me about. If you have both spacers hold on to 'em for me. EDIT: And if the jr west coast mirrors on that truck are in good shape I'd be interested in a set.

10-06-2004, 08:38 PM	#1
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	3/4 ton to dually conversion I'd like to hear from guys that have swapped 3/4 tons over to dual wheels. I know in the rear, you can just put the dual wheels on a single wheel truck. Do you have to change wheel studs? Didn't dually wheels change sometime to larger wheel stud holes? In the front, I've read the spindles are the same. Are the rotors the same too, or different? I know Dodge trucks use a spacer deal that bolts onto the 3/4 ton front rotor to space the wheel out further so a dually offset wheel will work. But after unbolting the spacer, the rotor is the same 3/4 to 1 ton. Is GM like this too?

10-06-2004, 08:41 PM	#2
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	GM does use a spacer but IDK if the rotor is the same. Should be, but not sure. It is this way on 2 and 4 wheel drive trucks. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

10-06-2004, 09:25 PM	#3
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	I wanted to do this too, but my truck has drums in the front. I'd have to swap 'em to discs right? __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

10-06-2004, 09:53 PM	#5
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	Damn, I figured it would work out that way. I have all the stuff to swap over to disc brakes, so the dually wheels should just bolt right onto those right? __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

10-06-2004, 09:56 PM	#6
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	That's what I'm trying to find out. I did a search and it seems that the 3/4 ton spindles and calipers are the same as 1 ton. I can't determine if the dually uses a huge offset rotor, or if it uses a 3/4 rotor with a big spacer hub bolted to it. I have a 72 3/4 ton disc brake truck to use at least the spindles and calipers, it's the rotors I need to know about. __________________ I'm on the Instagram- @Gearhead_Kevin

10-06-2004, 09:42 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	The drum beake dualies had different drums. Kinda hard to explain...but it had the section that spaces it out all as one piece. not just a spacer.

10-06-2004, 10:25 PM	#7
1972C10 Account Suspended Join Date: Dec 2003 Location: Texas Posts: 2,686	Its really simple Beat longer studs in the rear and put dookie rotors on the front. I converted one over a few years back.

10-06-2004, 10:35 PM	#9
1972C10 Account Suspended Join Date: Dec 2003 Location: Texas Posts: 2,686	Yeah man around these parts we call duallys dookies. You cant put the plate on outside of the wheel with stock studs.

10-06-2004, 10:44 PM	#10
72 CustomCamper huh ??? Join Date: Nov 2002 Location: Fredericksburg,Va. Posts: 3,369	Hey Tx Firefighter, it's a shame that you're half was across the US. I have everything here in Va that you would need to do the swap. I have a 78 dually that I parted out. Still have the drive train... Chuck __________________ 90 Blazer Silverado 350w/ 700R4 and 32" Kelly's "I am a bomb technician. If you see me running try to keep up!"

10-06-2004, 10:59 PM	#12
68w/sbc406 Got Light Emitting Diode? Join Date: Apr 2004 Location: Newberg, OR Posts: 2,485	i just paid 21 bucks to have some shipped from ECE wherever they are located to portland or. 2WD EDIT: they are in fresno California __________________ 1968 1/2 ton 2wd lwb 6 lug disc and bags up front. Next c notch and rear bags '02 Chevy Silverado LT ext cab short bed 2WD 5/7 drop on 22's(the family car) 1993 Cherokee work ride/weekend wheeler Last edited by 68w/sbc406; 10-06-2004 at 11:03 PM.

10-06-2004, 11:06 PM	#13
72 CustomCamper huh ??? Join Date: Nov 2002 Location: Fredericksburg,Va. Posts: 3,369	Yeah, still have the front cross member attached to the frame too. It's still sitting on the tires for the moment... Chuck __________________ 90 Blazer Silverado 350w/ 700R4 and 32" Kelly's "I am a bomb technician. If you see me running try to keep up!"

10-06-2004, 11:08 PM	#14
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,389	I am speaking of factory parts here--- the spindles are different between the 3/4 and 1 ton. The dually spindle takes a different caliper for a wider[thicker] rotor and thus needs the 1 ton dually spindle for the caliper mount. They do however use the same bearings and seals, ball joints also [ if i remember right ]

10-06-2004, 11:18 PM	#15
longhorn71 Senior Member Join Date: Sep 2004 Location: CANADA Posts: 1,681	I tried to put dual wheels on a 3/4 t rear end but the drums are different and would not allow the inside wheel to slide over the drum with a 16 " wheel. With the factory 18"wheels they were big enough to go around the drum but the tires are not made for those rims anymore. The brake drums on the factory dual wheel trucks have a longer cone shape to them.If you need a pic of the brake drum, I have one from 3/4t and a 1t. The one ton axle housing is narrower on the 1 t because of them having inboard brakes. Last edited by longhorn71; 10-06-2004 at 11:21 PM.

10-06-2004, 11:22 PM	#16
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Please post what pics you have. I did a search here and some guys said they would just slide onto the 3/4 ton rear. The search also said the spindles were the same too. I don't know what to think.

10-06-2004, 11:53 PM	#18
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	Ok thanks for the info. So I just need to get some front spacers right? __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck



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10-07-2004, 05:13 AM	#21
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	I'll see if I can get pics of the 72 C30 I'm going to buy. Where can you buy dually rims? and could someone explain the terminology. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm Last edited by JIMs70GMC; 10-07-2004 at 06:48 PM.

10-07-2004, 09:10 AM	#22
matt67350 Registered User Join Date: May 2001 Location: Benbrook, TX Posts: 1,060	I need to take the wheels off the 72, you can get a good look at the rotors then. __________________ 69 swb stepside, rebuild and upgrade in progress

10-07-2004, 10:52 AM	#23
mcmlxix Collector of Projects Join Date: Apr 2003 Location: Las Vegas Posts: 3,106	I just drove home a 72 C/30 Dually with camper. I'll see if I can get some pics today as well... __________________ Rich 1972 K5 Blazer CST Click HERE D60 BIG BRAKE UPGRADE Click HERE

10-07-2004, 12:37 PM	#24
PICKMUP "Trucks with Class" Join Date: Jul 2000 Location: OLYMPIA, WA, USA Posts: 8,169	This is a 72 3/4T Dana 60 rear that is converted to duals. It running in the truck when I got it. Appears to have added: big studs & lugs and a spacer. Attached Images __________________ Email: frankeham@comcast.net Phone: 360-956-7170

10-07-2004, 06:45 PM	#25
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	Yep, those studs and the lugs are way bigger that the ones on my truck. The drum almost looks the same though. Longhorn71, OK, I saw that blue 1 ton truck that you told me about. If you have both spacers hold on to 'em for me. EDIT: And if the jr west coast mirrors on that truck are in good shape I'd be interested in a set. __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck Last edited by Robert1970C20rstbukt; 10-07-2004 at 10:55 PM.

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