Are ADD hubs pretty much just manual hubs that are always locked?

GradSR5 · 11-11-2005, 03:17 PM

From what I've read, I can't really tell the difference between ADD hubs and manual hubs that are always locked. With ADD the drivetrain is always spinning, isn't that the same as manual hubs that are in the locked position?

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colsoncj · 11-11-2005, 03:20 PM

ADD trucks are equipped with flanges.... Check out this thread, it might help:

http://www.yotatech.com/showthread.php?t=70868

Basically a flange acts as a solid connection between the CV shaft and a wheel, opposed to a selectable connection like a hub.

6lug · 11-11-2005, 03:30 PM

Yes, the add flanges are like a locked hub. However, with a hub, you can unlock it to keep the drivetrain from moving.

GradSR5 · 11-11-2005, 03:41 PM

damn so those "add hubs" are kind of misrepresented if you ask me, i mean they arent really autolocking at all, theyre just always locked

AxleIke · 11-11-2005, 03:43 PM

you got it

runethechamp · 11-11-2005, 04:03 PM

The ADD is autolocking.

Cebby · 11-11-2005, 04:26 PM

There's a little more to it than that, but first I'd like to commend GradSR5 on searching and asking an intelligent question. Bravo!!

In addition to the drive flanges, the other components in the ADD system include an actuator on the long side of the front diff assembly that uses vacuum to disconnect the axle shaft from the diff. The rigs that came with manual hubs from the factory, don't have this actuator and all the related stuff, so they are a simpler more reliable system (by fewer parts). When I regeared, I just used an older non-ADD style front pig so I eliminated all the ADD stuff on mine with no ill-effects. I had replaced the flanges with manual hubs previously.

And no, ADD is not Autolocking. That is something different completely.

Flygtenstein · 11-11-2005, 04:43 PM

Take a look at one.

There are NO moving pieces, locking parts or ANYTHING LIKE THAT in an ADD drive flange.

ldivinag · 11-11-2005, 05:54 PM

Quote:

Originally Posted by runethechamp

The ADD is autolocking.

no, ADD ARE LOCKED by definition. since the flange connects the hub to the axleshaft.

toyota did come out with auto locking hubs. and from all reports i read, they would unlock at the worse moment...

ADD is not even part of the hubs. or visa versa.

it's the machanism that connects the driver's axleshaft to the differential.

ADD=auto disconnecting differential...

JamesD · 11-11-2005, 06:30 PM

Quote:

Originally Posted by GradSR5

From what I've read, I can't really tell the difference between ADD hubs and manual hubs that are always locked. With ADD the drivetrain is always spinning, isn't that the same as manual hubs that are in the locked position?

Your best bet is to convert to manual hubs. Use the search it has been done many times. It would probably save you a couple of dollars in gas too. Manual hubs are easy to rebuild and put less strain on the front drive system. If you are super lazy then stick with the Auto/ADD

James

runethechamp · 11-11-2005, 07:48 PM

Quote:

Originally Posted by ldivinag

no, ADD ARE LOCKED by definition. since the flange connects the hub to the axleshaft.

toyota did come out with auto locking hubs. and from all reports i read, they would unlock at the worse moment...

ADD is not even part of the hubs. or visa versa.

it's the machanism that connects the driver's axleshaft to the differential.

ADD=auto disconnecting differential...

Just read my post again. I said the ADD is auto locking. I never mentioned the hubs/flanges. The AUTOmatic Disconnecting Differential sleeve connects the axle automatically when you shift into 4wd.

bob200587 · 11-11-2005, 08:10 PM

worse than the ADD is the AUTO hubs. They were on my 4runner for all its life up until about 1 1/2 years ago. Its fun goin through mud with 4wd engaged and wondering why you're stuck. Def. go with manual hubs if you plan on changing. My best investment yet.

6lug · 11-11-2005, 09:00 PM

Quote:

Originally Posted by Cebby

There's a little more to it than that, but first I'd like to commend 6lug on searching and asking an intelligent question. Bravo!!

Actually, I didnt ask the question.

Cebby · 11-11-2005, 09:08 PM

Quote:

Originally Posted by 6lug

Actually, I didnt ask the question.

Oops! Sorry about that - fixed my post.

6lug · 11-11-2005, 09:27 PM

no worries

Flamedx4 · 11-12-2005, 11:43 AM

Sounds like some folks don't understand the 3 systems. (Three mentioned in this thread - there is also AWD - but lets leave that to the soccer moms...)

Manual hubs: When 4wd is engaged the front driveshaft drives the front diff and the front axle shafts turn. You manually engage and disengage the hubs by turning the lock ring on the hub by hand. Simplest and most reliable.

Auto hubs: When 4wd is engaged the front driveshaft drives the front diff and the front axle shafts turn. The axle torque to the cam mechanism inside the hubs themselves causes the hubs to engage to get the wheels to drive. To disengage it you put the transfer case back in 2wd and back up to get the hubs to disengage themselves. Note that in 4wd when you back up they must disengage then re-engage the other way - slamming back and forth (rocking) while stuck is a sure way to explode an auto hub. They are still quite simple but very weak and notoriously unreliable.

ADD: There are no 'hub' mechanisms. The "hub" is just a solid steel flange - so the axle shafts turn all the time with the tires. Instead, the front end engages into 4wd with the ADD mechanism - a vacuum operated axle disconnect which consists of a sliding splined sleeve on one front drive axle. In 2wd one drive axle is disconnected, owing to the action of the differential this 'unlocks' the front end. To engage 4wd, when the tcase is put in 4wd, vacuum is sent to the ADD mechanism, engaging the disconnected axle and now the front end works normally. To disengage, shift back into 2wd and vacuum will unlock that one axle allowing the front end to be non-driving again. The system is very strong and reliable - it's used in some form on nearly every 4wd made today. Once you get up to 35"+ tires and very severe 4wheeling you may find the strength limit. 99% of us could never break it. The vacuum switching valves and wiring are the only thing that are likely to need repair in time, but they are simple. Contrary to common conception, this system does not cost measureable fuel economy - the disconnected parts have so little resistance it makes no real difference.

Beach-Rat · 11-13-2005, 08:27 AM

What Flamedx4 said..

And.. I put manual hubs & locked the diff slider to engaged with a hose clamp on my '90.. worked like a manual system, trouble free after that..

Worked so well, I shoulda done it in '93 when I bought it.. would do my '96 if it had mounting holes on the stock hups.. whole nuther story..

bob200587 · 11-13-2005, 10:20 AM

I suppose technically you could keep the ADD and have manual hubs also.

Flamedx4 · 11-13-2005, 11:35 AM

Quote:

Originally Posted by bob200587

I suppose technically you could keep the ADD and have manual hubs also.

You bet. LOtsa people (including me) have done that. Best of both, you can lock the hubs beforehand and shift on the fly (nice in winter) or unlock for your day to day driving.

tc · 11-13-2005, 02:20 PM

But you didn't notice any gas mileage improvement?

Flamedx4 · 11-13-2005, 05:52 PM

Nope, none whatsover. Another way to consider it is if it really did cut gas mileage the factories probably would use it on everything - they need all the help with CAFE they can get. And it doesn't handle any different either, which I really thought it would. I have forgotten to unlock the hubs and driven for days - noticed nothing.

bob200587 · 11-13-2005, 05:59 PM

it vibrates on the highway more locked for me. thats about it.

tc · 11-13-2005, 07:10 PM

Wow - being on here may have actually SAVED me some money ... probably a first! LOL

Glenn · 11-13-2005, 09:28 PM

Quote:

Originally Posted by bob200587

it vibrates on the highway more locked for me. thats about it.

Your front driveshaft may be out of synch. Try rotating it ¼ turn. I used to have a front driveline vibration, and fixed it by turning it ¼ turn.

bob200587 · 11-13-2005, 09:49 PM

its no big, I only lock em up when I'm wheeling. so its not much of a problem.

11-11-2005, 03:20 PM	#2 (permalink)
colsoncj Contributing Member Join Date: Jun 2004 Location: Monett, MO (Springfield) Posts: 2,533	ADD trucks are equipped with flanges.... Check out this thread, it might help: http://www.yotatech.com/showthread.php?t=70868 Basically a flange acts as a solid connection between the CV shaft and a wheel, opposed to a selectable connection like a hub. __________________ Cory Eastern OK, Western/Northern AR, Southeastern KS, or Southern MO area: OZARKS 4ROC Click Here 04 Dodge 2500 Cummins - DD/Tow Rig 02 Z06 Corvette - Weekender 94 FZJ80 - Wheelin Rig. Build in progress: http://ttora.com/forum/showthread.php?t=129727 72 Buick GS - i.e. the project that will never get done. Last edited by colsoncj; 11-11-2005 at 03:21 PM.

11-11-2005, 03:30 PM	#3 (permalink)
6lug Registered User Join Date: Sep 2005 Location: Sevierville, TN Posts: 292	Yes, the add flanges are like a locked hub. However, with a hub, you can unlock it to keep the drivetrain from moving. __________________ 1993 4Runner, V6, auto, 4.56's, custom rear bumper/tire carrier, Marlin's sliders, All Pro's rear spacers, Warn manual hubs, Surco rack (slightly customized), lights, on 31's, Lockright out back, Safari Snorkel. Now...1998 Jeep Cherokee, 4.0, AW4, 231, HPD30, C8.25, Skyjacker 4", 31" BFG ATs, custom frnt bumper/winch

11-11-2005, 03:41 PM	#4 (permalink)
GradSR5 Registered User Join Date: Oct 2005 Posts: 20	damn so those "add hubs" are kind of misrepresented if you ask me, i mean they arent really autolocking at all, theyre just always locked __________________ '92 4runner SR5 v6 3.0L 4x4 126k mi, 31" tires, stock other than that.

11-11-2005, 03:43 PM	#5 (permalink)
AxleIke Contributing Member Join Date: Apr 2004 Location: Boulder, Colorado Posts: 4,848	you got it __________________ 1987 Mutant 4runner. -Lifts and Tires look cool at the Mall, Lockers and Gears look cool on the trail.

11-11-2005, 04:03 PM	#6 (permalink)
runethechamp Registered User Join Date: Oct 2005 Location: Berkeley, CA Posts: 586	The ADD is autolocking. __________________ 94 4runner SR5, V6 3VZE, 5 speed Completely rebuilt engine with Toyota parts at 147k miles Downey Coils, Aisin manual hubs, Cowl Louver mod, Hella 500 fog lights Yeah, I know, not many cool mods here

11-11-2005, 04:26 PM	#7 (permalink)
Cebby Contributing Member Join Date: Sep 2002 Location: Pittsburgh, PA Posts: 11,246	There's a little more to it than that, but first I'd like to commend GradSR5 on searching and asking an intelligent question. Bravo!! In addition to the drive flanges, the other components in the ADD system include an actuator on the long side of the front diff assembly that uses vacuum to disconnect the axle shaft from the diff. The rigs that came with manual hubs from the factory, don't have this actuator and all the related stuff, so they are a simpler more reliable system (by fewer parts). When I regeared, I just used an older non-ADD style front pig so I eliminated all the ADD stuff on mine with no ill-effects. I had replaced the flanges with manual hubs previously. And no, ADD is not Autolocking. That is something different completely. __________________ UZswap.com A site dedicated to sharing info for swapping the Toyota/ Lexus UZ (V8) engines into Toyota Trucks and 4Runners. My 4Runner 1993 4Runner, 1UZ (V8) auto dual ultimate crawler, double locked, 35's on beadlocked SR5 alloys, low lift, hacked fenders, tubbed firewall, custom armor TOOLandFAB.com A discussion forum dedicated to tools, fabrication & workshops. See my JD2 Bender Hydro Conversion BUY THIS 2008 CALENDAR Last edited by Cebby; 11-11-2005 at 09:07 PM.

11-11-2005, 04:43 PM	#8 (permalink)
Flygtenstein Registered User Join Date: Sep 2002 Location: Fort Collins, CO Posts: 4,246	Take a look at one. There are NO moving pieces, locking parts or ANYTHING LIKE THAT in an ADD drive flange. __________________ Ease on down the road.

11-11-2005, 08:10 PM	#12 (permalink)
bob200587 Contributing Member Join Date: Feb 2005 Location: Nashville, TN Posts: 2,843	worse than the ADD is the AUTO hubs. They were on my 4runner for all its life up until about 1 1/2 years ago. Its fun goin through mud with 4wd engaged and wondering why you're stuck. Def. go with manual hubs if you plan on changing. My best investment yet. __________________ 87 4runner 4x4 SR5 22RE ARB Bull Bar, 31X10.50 Mastercraft M/T's, Stock 4.10 Gears, Flowmaster Muffler, LCE Header AISIN Manual Hubs, Marlin Crawler Sliders 190XXX miles

11-11-2005, 09:27 PM	#15 (permalink)
6lug Registered User Join Date: Sep 2005 Location: Sevierville, TN Posts: 292	no worries __________________ 1993 4Runner, V6, auto, 4.56's, custom rear bumper/tire carrier, Marlin's sliders, All Pro's rear spacers, Warn manual hubs, Surco rack (slightly customized), lights, on 31's, Lockright out back, Safari Snorkel. Now...1998 Jeep Cherokee, 4.0, AW4, 231, HPD30, C8.25, Skyjacker 4", 31" BFG ATs, custom frnt bumper/winch

11-12-2005, 11:43 AM	#16 (permalink)
Flamedx4 Registered User Join Date: May 2004 Location: 100 miles offshore as much as possible, & Springfield Oregon USA Posts: 3,285	Sounds like some folks don't understand the 3 systems. (Three mentioned in this thread - there is also AWD - but lets leave that to the soccer moms...) Manual hubs: When 4wd is engaged the front driveshaft drives the front diff and the front axle shafts turn. You manually engage and disengage the hubs by turning the lock ring on the hub by hand. Simplest and most reliable. Auto hubs: When 4wd is engaged the front driveshaft drives the front diff and the front axle shafts turn. The axle torque to the cam mechanism inside the hubs themselves causes the hubs to engage to get the wheels to drive. To disengage it you put the transfer case back in 2wd and back up to get the hubs to disengage themselves. Note that in 4wd when you back up they must disengage then re-engage the other way - slamming back and forth (rocking) while stuck is a sure way to explode an auto hub. They are still quite simple but very weak and notoriously unreliable. ADD: There are no 'hub' mechanisms. The "hub" is just a solid steel flange - so the axle shafts turn all the time with the tires. Instead, the front end engages into 4wd with the ADD mechanism - a vacuum operated axle disconnect which consists of a sliding splined sleeve on one front drive axle. In 2wd one drive axle is disconnected, owing to the action of the differential this 'unlocks' the front end. To engage 4wd, when the tcase is put in 4wd, vacuum is sent to the ADD mechanism, engaging the disconnected axle and now the front end works normally. To disengage, shift back into 2wd and vacuum will unlock that one axle allowing the front end to be non-driving again. The system is very strong and reliable - it's used in some form on nearly every 4wd made today. Once you get up to 35"+ tires and very severe 4wheeling you may find the strength limit. 99% of us could never break it. The vacuum switching valves and wiring are the only thing that are likely to need repair in time, but they are simple. Contrary to common conception, this system does not cost measureable fuel economy - the disconnected parts have so little resistance it makes no real difference. __________________ All my Yotas are gone. Stuff to sell: http://www.yotatech.com/showthread.p...39#post1009839 -Phil Last edited by Flamedx4; 11-12-2005 at 11:46 AM.

11-13-2005, 08:27 AM	#17 (permalink)
Beach-Rat Registered User Join Date: Jan 2003 Location: Northern VA Posts: 50	What Flamedx4 said.. And.. I put manual hubs & locked the diff slider to engaged with a hose clamp on my '90.. worked like a manual system, trouble free after that.. Worked so well, I shoulda done it in '93 when I bought it.. would do my '96 if it had mounting holes on the stock hups.. whole nuther story..

11-13-2005, 10:20 AM	#18 (permalink)
bob200587 Contributing Member Join Date: Feb 2005 Location: Nashville, TN Posts: 2,843	I suppose technically you could keep the ADD and have manual hubs also. __________________ 87 4runner 4x4 SR5 22RE ARB Bull Bar, 31X10.50 Mastercraft M/T's, Stock 4.10 Gears, Flowmaster Muffler, LCE Header AISIN Manual Hubs, Marlin Crawler Sliders 190XXX miles

11-13-2005, 02:20 PM	#20 (permalink)
tc Contributing Member Join Date: Nov 2005 Location: Longmont, CO Posts: 8,327	But you didn't notice any gas mileage improvement? __________________ Check out www.coTTORA.org to hook up with great Toyota 'wheelin' folks! Current - 93 4Runner: 3VZ 33"x10.50" no lift ARB F/R 96 Impala SS: My own personal cop car Previous - 89 2WD Pickup 22R, Fabtech "Ivan Dan" lift, 31x10.50, IASCA World Finals 4th Place Stop with the mods and get on the trail! Pix at www.4wheelingoh.shutterfly.com/action

11-13-2005, 05:52 PM	#21 (permalink)
Flamedx4 Registered User Join Date: May 2004 Location: 100 miles offshore as much as possible, & Springfield Oregon USA Posts: 3,285	Nope, none whatsover. Another way to consider it is if it really did cut gas mileage the factories probably would use it on everything - they need all the help with CAFE they can get. And it doesn't handle any different either, which I really thought it would. I have forgotten to unlock the hubs and driven for days - noticed nothing. __________________ All my Yotas are gone. Stuff to sell: http://www.yotatech.com/showthread.p...39#post1009839 -Phil

11-13-2005, 05:59 PM	#22 (permalink)
bob200587 Contributing Member Join Date: Feb 2005 Location: Nashville, TN Posts: 2,843	it vibrates on the highway more locked for me. thats about it. __________________ 87 4runner 4x4 SR5 22RE ARB Bull Bar, 31X10.50 Mastercraft M/T's, Stock 4.10 Gears, Flowmaster Muffler, LCE Header AISIN Manual Hubs, Marlin Crawler Sliders 190XXX miles

11-13-2005, 07:10 PM	#23 (permalink)
tc Contributing Member Join Date: Nov 2005 Location: Longmont, CO Posts: 8,327	Wow - being on here may have actually SAVED me some money ... probably a first! LOL __________________ Check out www.coTTORA.org to hook up with great Toyota 'wheelin' folks! Current - 93 4Runner: 3VZ 33"x10.50" no lift ARB F/R 96 Impala SS: My own personal cop car Previous - 89 2WD Pickup 22R, Fabtech "Ivan Dan" lift, 31x10.50, IASCA World Finals 4th Place Stop with the mods and get on the trail! Pix at www.4wheelingoh.shutterfly.com/action

11-13-2005, 09:49 PM	#25 (permalink)
bob200587 Contributing Member Join Date: Feb 2005 Location: Nashville, TN Posts: 2,843	its no big, I only lock em up when I'm wheeling. so its not much of a problem. __________________ 87 4runner 4x4 SR5 22RE ARB Bull Bar, 31X10.50 Mastercraft M/T's, Stock 4.10 Gears, Flowmaster Muffler, LCE Header AISIN Manual Hubs, Marlin Crawler Sliders 190XXX miles

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