Free wheeling hubs?

Before you respond, if you are at all considering responding with anything along the lines of "it cant be done", please dont respond, that answer is not helpful in the least.

What I have been looking at are the service manuals for 2000, 2004, and 2005 tacoma 4x4's. What is very clear is that the general design and configuration of the front hubs and related components havent changed in any dramatic fashion. In fact going just by the pictures, it practically looks like you could just bolt a set of 2000 hubs onto a 2005+.

Up to 2000, there were two configurations available from factory; ADD and free wheeling hubs. In 2001, without changing anything else, the free running hub option was no longer available. Now in these models, from 2001 through 2004, you could install the 2000 free running hubs simply by bolting them on.

Though the service manuals show the 1st gen ADD hubs to look the same as 2nd gen, there is a difference in the part numbers. Looking at 43502-04130 for 2nd gen, 43502-04040 1st gen w/ADD, 43502-04030 1st gen without ADD.

Now I have seen several components that Toyota uses on various vehicles with different part numbers, actually be compatible with each other. Different, but compatible. Or different and *mostly* compatible. There are, for example, differences in the front wheel ABS sensors between 1st and 2nd gen, so something like this may be the real difference.

I guess what I am looking for, is anyone who has worked extensively with the front hubs on both 1st and 2ng gen, to give a description on how similar or different the hubs actually are. Ideally, I would hope them to be similar enough to be bolt-on replacements, and even if the speed sensors arent compatible, I could work with that and rig up something to deal with it.

Has anyone actually attempted a 1st free wheeling hub to 2nd gen upgrade?

 

My only question is why? You won't gain anything. This question had been asked several times-search.

 

Honestly, I don't know why you'd want them. In all actuality, they suck. I've done lots of wheeling in old 4x4s and you always end up getting sunk in a mudhole or snowdrift and have to get out and dig down in the mud or snow to lock them in. With the automatic hubs, just flip a switch and off you go. Plus if you do any deep water crossing, be prepared to take the hubs apart and re-pack them with bearing grease each time. If I could, I'd convert my old Bronco and Jeep to automatic hubs. I am pretty sure on the Tacoma when it is in 2WD the front end drive components are all disengaged so your front wheels free-wheel anyway. But I am not for certain, still learning about these newer 4x4 setups. If you do decide to do a conversion, I would like to see a thread about it, sure everyone else would too.

 

Actually they don't suck, they work just fine. If and when you plan on wheeling, one would simply lock them, go off and run in 2wd, then when more traction is needed simply shift the transfercase into 4hi or 4 lo depending on the situation, then when the traction is no longer needed or paved roads are driven on just shift back to 2HI. I do this all the time, infact the front hubs can be left locked if the transfercase has a lever to manually take it into and out of 4WD, granted my Truck is a 1999 where everything is manual, I guess it's older technology but it gets the job done.

 

I would love manual hubs on my 2011. Then again, I'd also love manual steering and manual t case lol I wouldn't do the swap "on purpose," but if (when) my front wheel bearings go I definitely would. Maybe if you could swap the wheel bearings and cv axles it would work. I believe the way our trucks are set up is the front wheels are locked to the cv axles and the front driveshaft unlocks from the front axle and the t case. Atleast that's what it looks like to me. Keep us posted if you figure somethin else!

 

Right, some of you have got the idea.
There are definitely at least THREE reasons I can think of to do this modification;

1) Available 2wd-low range.
2) reduced wear on front end parts that now will not be moving,
3) reduced fuel consumption due to reduced friction in front end components.

I'm almost tempted to just buy a freewheeling 2000 hub to find out how different or similar they are, they're under $140.


And as has been mentioned, this isn't something that you would lock/unlock every time you go into or out of 4wd. The ADD would remain in the system, so if you're anticipating potential sticky situation, one could simply lock the hubs in advance. If you live where there is snow, locked for winter, unlocked for summer.

-- of course, you could also go with auto-lockers, though they can be a bit temperamental.

 

I've never been stuck in a mudhole in my life, and don't plan to ever try it. As for snow... 2wd won't get you far enough to bury your front hubs.

And no, in all Tacomas starting in 2001, the hubs remain fully engaged full time. There is only a shaft disconnect on the passenger side of the front differential.

 

As you pointed out, the ADD remains in the system.

To me, the main advantage of such a conversion would be that the front diff ADD actuator is a temperamental beast and is subject to failure. However, removing it would be a bit of a pain, as the 4WD control unit sends it electronic inputs - and expects outputs, and will throw a code and fail to engate the transfer case if it doesn't get what it's expecting.

Not to mention installing a custom cover to replace the existing actuator and slide fork that would always be in the "engaged" position.

As far as the gas mileage thing goes - you KNOW how much the manufacturers are pressured to get their mileage numbers up. If there were a meaningful gain to be had on the disconnecting hubs vs. the disconnecting front differential - doncha think they'd be on that like rats on a cheese?

So no, I don't think it can't be done. I just don't think you've yet come to a realistic assessment of the benefits vs. tradeoffs.

 

Disconnecting the ADD feed and running it through a switch would be an easier way to get 2Lo and I believe has been pioneered already.

Just offering a possible solution for one of the end results you were looking for.

 

I agree with this. I would like them for reliability reasons, but I also have a "manual" ADD system with a switch on the dash and a twin stick transfer case. The gas saving would be nil because all that rotates now is one axle shaft and the spider gears.

Yes, there are write-ups on this mod.

 

No, my assessment is perfect in every way, and in any case, I have no interest whatsoever in advice, that isnt the purpose of this thread, the purpose of this thread is to collect information regarding the feasibility of actually making such modifications.

I would like to point out that you have made an invalid assumption in your statement -- that the manufacturer must have considered fuel consumption and determined that ADD was optimal. You have made the assumption that there is nothing to consider besides fuel consumption. This is incorrect. ADD is far easier to operate than any kind of locking hubs, including automatic hubs. No hubs allow for a shift from 4wd to 2wd while in motion, and though automatic hubs do allow for 2--4 shift in motion, this is only at low speed. auto hubs require you to stop and reverse to disengage. Now consider how difficult it is just to get people not to drive full time in 4wd on dry pavement, do you expect a city poser's wife to not royally screw up a vehicle with locking hubs? ADD is a tradeoff against fuel consumption for ease of use.

The fuel consumption difference between locking hubs and ADD can be found by comparing the highway fuel consumption of a prerunner and otherwise identical 4x4, specifically, 3 mpg. Prerunner AC 2.7 is quoted at 24 mpg, 4x4 at 21. The minor weight difference of 235 pounds does not account for this.

As far as removal of the ADD, if this is something that appeals to you, it would be fairly trivial. In fact the ADD on my YJ broke, I slipped the collar over the shafts, cut a groove around the drive side shaft, and snapped on a snap ring to hold the collar from backing off. I removed the shift fork and reinstalled the remainder of the ADD without plugging in the wire. That vehicle now can only disconnect at the transfer case, but as a full time offroad plow truck, I have no need for 2wd on it.

 

This would not be necessary with free running hubs.

But again, I have no interest in advice. All I'm interested in is knowledge regarding feasibility.

 

Since you don't want advice, just go SAS and enjoy your free wheeling hubs.

 

Well obviously no point in seeking information here, nobody around but a bunch of children determined to degenerate every discussion into a dick measurment session.

 

So it might be necessary, or easier, to swap out the entire front diff with that of a 1st Gen but that could put you into the fabrication realm to get it mounted up.

 

$1,000 buys a lot of gas... That right there would take the fuel economy gains out of the equation for me unless my CV's were blown anyways and needed replacing (or did a lot of off roading and didn't want to rely on the ADD system but that again would make the mod for the sake of fuel savings moot).

 

It can not be done because CV on 1gen is 27 spline and one on 2gen is 30 spline. I can get you a picture how much difference in size there is so bolting 1gen hubs to 2gen is Impossible.
However. if you get LC spindles to work on 2gen then you can get manual hubs on 2gen.

 

BTW I want to go opposite way. I want AWD option on my truck. add as is currently is fine. What Double cab long bad needs is AWD so in winter its easier to plow and handle ice/snow/asphalt mixture.