Push button locking hubs

[JoeV]

I have a dualcab SR5 TD Hilux with the push button locking hubs. Ive had manual hubs in the past. My question is what happens if the solinoid goes and it can't be locked in, is there a manual way of locking the hubs or are you stuck in 2wd
Cheers

[muddy]

There is no manual override but I really wouldn't be too conserned but also fitting free wheeling hubs wont actually remove the system as it operates on the front diff and transfer case! Just check the breather line on the electric motor on the transfer from time to time as I have had these split on some before and water wrecks the motor but thats the only real issue I've seen.

[Peter @ Aawen4x4]

Are you sure that it's push button locking hubs, and not the ADD diff system. Most of the Hilux SR5's run an Automatic Disconnect Differential, ADD. This is electrically activated, and when you press the button to select 4WD, it activates a solenoid that drags a collar across inside the diff, and locks the passenger (??) side front axle into the diff. The Driver's side is always connected, and hence always turning (driven by the wheel on the road), but 'cos the diff is an open diff, and the passenger side axle isn't engaged, it won't drive, just freewheel.

If yours is the same as most SR5's, you don't have any freewheeling hubs at all, not auto or manual!! Many SR5 operators fit manual freewheeling hubs, 'cos the ADD is renowned for disconnecting when you least want it too!! By fitting freewheeling hubs, you can disable the ADD, and with a little spanner work, permanently fix the passenger axle into the diff just like every other diff, then you get about by using the hubs exactly like every other 4WD!!

Hubs unlocked to let you Free wheel when you are in 2WD; select low for backing the boat or trailer up the drive, but leave the hubs unlocked; lock the hubs once a week/month to slosh the oil around in the diff and keep things lubed, driving the car in 2WD for a couple of k's/hour's/day's; lock the hubs when you leave home heading off 4wheeling, letting the oil slosh around and everything warm up while you're driving there, then just pull the lever (or press the button) to select 4WD as and when you hit the dirt!! When you come home, select 2WD when you hit the bitumen, and when you get home you can crawl out of the car and set the hubs in free while you're down there!! If you're not crawling, you didn't 4by HARD enough!! ;D

[fromunder4x4]

if its a IFS hilux SR5 it will be the ADD system
I fitted free wheeling hubs to stop wear on the front shafts and CV boots
I think last time i priced them from toyota $300 a set to do the two shafts
$60 for after market bits but only lasted 10 000k's but now fitted after market boots and free wheeling hubs no sign of splitting because they are not turning the sharts any more only the wheels i think i have done about 40 000k's now

PS i remember seeing something about manual over ride on the front diff ADD system in one of my books will have to look it up and get back to you all
;D ;D ;D

[baby_troupe]

Yes there is a manual way to lock them in.

I have push button hubs in my import prado.

Remove the cover from the hub & the normal engage mechanism & manually twist the gear to the lock position.
Then put the cover back on.

Make sure you do both though & disconnect the switch so the working one does not disengage.

[BryanW]

I fitted free wheeling hubs to stop wear on the front shafts and CV boots
I think last time i priced them from toyota $300 a set to do the two shafts
$60 for after market bits but only lasted 10 000k's but now fitted after market boots and free wheeling hubs no sign of splitting because they are not turning the sharts any more only the wheels i think i have done about 40 000k's now

Sorry guys I'm not sure I understand too well. In a lux with ADD system does it basically have only one wheel connected to the differential? And then when you select 4H it locks the other one?

You also say there there is more wear with the ADD? Please explain. I really dont see why we need this new stuff, how lazy could anyone be to go lock the hubs, at least it works all the time.

Cheers

[Peter @ Aawen4x4]

With the ADD system, 1 side of the front axle is absolutely standard, same as any other 4by WITHOUT FREEWHEELING HUBS! (I think it's the passenger but can't remember xactly) So that means that side will turn whenever the front pass side wheel is ground driven as you drive along. Because open diffs will only ever turn the easiest wheel to turn, the one with NO traction, this effectively works backwards up towards the driveshaft and lets the passger side axle spin like buggry with the ground driven wheel, and spin the diff centre, but the planetary gears rotate as well, allowing the passing of NO driven force up the driveshaft or out the other side!

Most 4WD's without freewheeling hubs have BOTH axles engaged, and both axles will turn, impacting on steering, making the engine work harder to PUSH the extra weight, and costing more in terms of fuel usage and wear on components. The diff does the same as above though, allowing NO driven force to be pushed back up the shaft. Toyota with the ADD took the approach that 1 side turning would remove most (but not ALL) the steering impacts, lower the weight being pushed around, reduce the fuel cost and limit the wear by half, while still giving a strong and electrically operated switch for 4WD selection!

With ADD, when the 4WD button is pressed, there is a selector yoke and a collar that pushes the drivers side axle spline into its working position in the diff, making the diff identical to a working 4by with 4WD selected. That yoke has been known to have issues in its operation, and the impacts on fuel, wear, driving, steering are still there. A normal part time 4by avoids this by using freewheeling hubs set to FREE!

So, many people with ADD front axles, take the option of fitting REAL FREEWHEELING hubs, and then neither side wheel is connected to the axle when the hub is in the FREE position, so the axles don't turn and nothing inside the diff turns, wears, cost more to push, etc! It means that for the ADD to work, you still hafta get out and lock hubs though, so it is a bit of overkill. And 'cos you can unwittingly select 4WD and have the hubs free, it can be a pain! To solve that, most open the ADD selector, physically engage the yoke and collar by hand, and then lock them in that position by various means, another collar or locking ring, maybe a hose clamp usually works! They then disable the solenoid operation at the axle end, leaving the 4WD switch to engage the transfer case only! That means that the axles are identical to the normal part time 4by, and are inserted into the diff at all times; the freewheeling hubs do the work of isolatinf the wheels when in the free position; and when in the lock position, the axles turn, the driveshaft turns and when you select 4wd with the stubby lever, OR with the 4WD button, the transfer case diverts drive to the front!!

Does that make it any clearer?? It was/is an attempt by Toyota to give some of the advantages of having switchable 4WD from inside the cab whilst not having to get out and lock the hubs!! Auto locking hubs are another way, and were around before Toyota did ADD, but were renowned for spurious operation as and when they felt like it, giving rise to expensive repairs and hassles when trying to 4WD but the hubs kept releasing!! ADD didn't really live up to its advertising, and it too was a pain at times, hence there are very few ADD systems actually in operation on 4By's that are used often in 4WD circumstances!!

Have Fun!

[foxy]

So does anyone know which system Mazda and Mitsubishi use??

My Current model Bravo dually has to be stopped to lock the hubs electronically, once they are locked you can shift between 2wd and 4wd high on the fly.

My brothers Triton 4WD can be shifted from 2WD to 4WD on the fly using the transfer case lever up to 100kph, he has no independant hub locking button at all........

I don't go through the full on stuff offroad, but have done sections of the border track, some dodgy mud and bog holes, deep sand at Goolwa beach etc and the system on my Mazda has never disengaged or failed........though after reading this thread I am a little concerned!!! :-\