Electric hubs? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Russell · 12-20-2004, 02:01 AM

Hey guys!

I'm about to make the swap to 4x4 here... Now, I am a bit concerned about the hubs on the front axle here... I have a set of wheels from a 2005 GMC 2500 HD (the alloy wheels) and really don't want to bore out the caps for the front hub. How (un)reliable are the electric hubs, and what would it take to install them? How much more than a 14 bolt FF hub would stick out?

Thanks!

Russ

**JIMs70GMC** · 12-20-2004, 07:57 AM

This is a new one for me, electric hubs??? Do you mean auto hubs?

**Stocker** · 12-20-2004, 12:14 PM

No, I think they use electric heaters to expand a gas or fluid, which engages the hubs. A buddy of mine says he had them (stock) on his '88 K20 and they could take several seconds to heat up enough to engage in cold weather... and in a creek crossing, they could cool off enough to disengage! Hearing that, they would not be my first choice...

**JIMs70GMC** · 12-20-2004, 12:45 PM

Sounds like the CAD, center axle disconnect?

Mudder · 12-20-2004, 12:51 PM

I've never heard of em, but then theres lots of new stuff out there I don't know about.

**Stocker** · 12-20-2004, 12:59 PM

Quote:

Originally Posted by JIMs70GMC

Sounds like the CAD, center axle disconnect?

Hmmm, could be, obviously I'm not familiar with this application and may have heard wrong...

In that case, are the hubs always engaged?

1969 GMC · 12-20-2004, 01:32 PM

Russ,

what front axle are you using? Maybe that could help us out a little more.

Russell · 12-20-2004, 02:52 PM

Dana 44 from a 3/4 ton 78

By electric I mean the setup that heats up the axle to engage the lockers. I do live in an area that gets extremely cold (colder than -40 F) so that may be a problem....

I just wanted to avoid having to get the cap bored out to fit the axle's hub through it :p I guess I can if I have to

**JIMs70GMC** · 12-20-2004, 09:26 PM

post a pic. That should be an external hub design "big". Unless of course it's from a full time 4wd truck then it should have drive flanges nothing to lock.

DirtyLarry · 12-20-2004, 09:49 PM

You guys are getting different systems confused.

Hopefully, this will help….

Pre-1981 - trucks had manual locking hubs unless equipped with a NP203 fulltime tranfercase. Then no hubs at all…only a silver cap covering the hub bearings.

1981-1987 - C/K (1987-1991 R/V old body style) models had either manual locking hubs or automatic locking hubs.

1988-1994 GMT400 - newer body style IFS trucks had a thermal electric front-axle disconnect. (not locking hubs but the same principle…. The thermal disconnect, separates the axle(s) from the ring gear) Basically, when the tcase lever is moved a button is grounded and the front axle disconnect heats up a solid substance and turn it to a gas allowing a shift fork to move and connect with the front axle shaft engaging 4wd.

1995- present GMT400 and GMT800 – had fully electric front axle disconnect….no chemistry trickery with gases here….The electric motor to allows the shift fork to engage the front axle(s). Not very reliable I must add.

This is not the same as electric shift transfercase! Which, are even less reliable.

**JIMs70GMC** · 12-21-2004, 07:19 AM

That sums it up, I'll never buying anything newer than a 72!
Russell, your stuck with your big hubs.

Russell · 12-23-2004, 02:00 AM

Hmm, I guess I'll just run a set of steels until I figure out what I am gonna do with the wheel caps then

12-20-2004, 02:01 AM	#1
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	Electric hubs? Hey guys! I'm about to make the swap to 4x4 here... Now, I am a bit concerned about the hubs on the front axle here... I have a set of wheels from a 2005 GMC 2500 HD (the alloy wheels) and really don't want to bore out the caps for the front hub. How (un)reliable are the electric hubs, and what would it take to install them? How much more than a 14 bolt FF hub would stick out? Thanks! Russ __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

12-20-2004, 07:57 AM	#2
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	This is a new one for me, electric hubs??? Do you mean auto hubs? __________________ 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

12-20-2004, 12:14 PM	#3
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,806	No, I think they use electric heaters to expand a gas or fluid, which engages the hubs. A buddy of mine says he had them (stock) on his '88 K20 and they could take several seconds to heat up enough to engage in cold weather... and in a creek crossing, they could cool off enough to disengage! Hearing that, they would not be my first choice... __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

12-20-2004, 12:45 PM	#4
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Sounds like the CAD, center axle disconnect? __________________ 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

12-20-2004, 01:32 PM	#7
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	Russ, what front axle are you using? Maybe that could help us out a little more. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

12-20-2004, 12:51 PM	#5
Mudder Registered User Join Date: Feb 2001 Location: East Central, MO Posts: 11,336	I've never heard of em, but then theres lots of new stuff out there I don't know about.

12-20-2004, 02:52 PM	#8
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	Dana 44 from a 3/4 ton 78 By electric I mean the setup that heats up the axle to engage the lockers. I do live in an area that gets extremely cold (colder than -40 F) so that may be a problem.... I just wanted to avoid having to get the cap bored out to fit the axle's hub through it :p I guess I can if I have to __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

12-20-2004, 09:26 PM	#9
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	post a pic. That should be an external hub design "big". Unless of course it's from a full time 4wd truck then it should have drive flanges nothing to lock. __________________ 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

12-20-2004, 09:49 PM	#10
DirtyLarry Windy Corner of a Dirty Street Join Date: Jun 2003 Location: Pueblo West, Colorado Posts: 2,926	You guys are getting different systems confused. Hopefully, this will help…. Pre-1981 - trucks had manual locking hubs unless equipped with a NP203 fulltime tranfercase. Then no hubs at all…only a silver cap covering the hub bearings. 1981-1987 - C/K (1987-1991 R/V old body style) models had either manual locking hubs or automatic locking hubs. 1988-1994 GMT400 - newer body style IFS trucks had a thermal electric front-axle disconnect. (not locking hubs but the same principle…. The thermal disconnect, separates the axle(s) from the ring gear) Basically, when the tcase lever is moved a button is grounded and the front axle disconnect heats up a solid substance and turn it to a gas allowing a shift fork to move and connect with the front axle shaft engaging 4wd. 1995- present GMT400 and GMT800 – had fully electric front axle disconnect….no chemistry trickery with gases here….The electric motor to allows the shift fork to engage the front axle(s). Not very reliable I must add. This is not the same as electric shift transfercase! Which, are even less reliable. __________________ Current vehicle collection: 1978 Chevrolet K10, 8.1L, NV4500, NP205 1989 Chevrolet Suburban, 8.1L, NV4500, NP241 1993 Chevrolet C1500 Sportside, TBI 7.4L, 4L60E 2001 Chevrolet K2500HD, Ext Cab, SWB, 8.1L, ZF 6 speed 2014 Chevrolet Impala LTZ 3.6L Vortec 8.1L because life is too short to tolerate underpowered vehicles Instagram

12-21-2004, 07:19 AM	#11
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	That sums it up, I'll never buying anything newer than a 72! Russell, your stuck with your big hubs. __________________ 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

12-23-2004, 02:00 AM	#12
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	Hmm, I guess I'll just run a set of steels until I figure out what I am gonna do with the wheel caps then __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)



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