4x4 Free-Wheeling Front End?

...Howdy!

...Not too sure where to post this question...so started this thread?

...I have been away from 4x4s for about 30-40 years..( yes..I am an old-fart )...but looking to get a new 4x4 Tacoma...

...In past had a 4x4 Suburban..and an old-style Land-Rover....( NOT these yuppiefied suv pieces of shit today...but the gnarly original with the big-ass tire on the hood, tropical roof, 9 leaf-springs on front wheels..10 springs on back, etc )...Amazing OR...but beat ya to death on paved road!...LOL!....

...Anyway, with a 4x4, when ya are in 2wd, all that good stuff is still spinning up front, causing drag and wear...and killin mpg.....

...So...there was/is a company named WARN, that sold a free-wheeling hub that you attached to the front wheels that had a selector handle....OFF when toolin around in 2wd....and ya stopped and turned handle to Engage the gears again for 4wd....Essentially what it did was disconnect the wheel from the front shaft...allowing it to spin freely like a regular 2wd vehicle......

...Asked the guys at service, and they said Toyota stopped offering this back in the 90s...as the newer 4x4s were better engineered. But it still seems to me those all that spinning-goodies up front when in 2wd will still wear and drag....so the mpg will go down...and you will need to do major work on the front-end sooner?

...Am I anywhere near correct about this now?...or does it still matter?...Thanks!

 

Pretty sure modern hubs already disconnect from the driveline when not in 4x4. Someone can correct me if i'm wrong.

 

I don't think there's anything in our hubs that disconnect. Our CV's are always spinning with the wheels.

 

...Well...OK...less than 15 minutes and we gotz 2 opposite replies!.......Thanks!

 

CV's are always spinning.

 

The front CV's always spin. The passenger side front diff has an actuator that disconnects that CV internally from the diff itself, This allows the front driveshaft (from the tcase to front diff) and front diff itself to freespin or not spin at all. this is called toyota ADD (automatic differential disconnect).

While it might be nice to have good ole manual hubs, MPG gains would be minimal.

 

...Thanks for the clarification...and that would explain WHY Toyota could stop offering the manual hubs as an option..

..but not too clear on why mpg would be minimal?...I mean, if front drive-shaft, front-diff, and two front axles are turning with the wheels, or more accurately, being turned by the wheels instead of driven by t/case.....wouldn't that create a lot more drag that would potentially suck up MPGs?

...Oh, yeah....also forgot to mention that if you DID put on manual-hubs...most likely you would also nullify your warranty?!...DOH!

 

It would only void the parts that the modification affected. For instance, IF you put on manual hubs, and then lets say your seat adjuster broke, that would stay under warranty.

http://www.consumer.ftc.gov/articles/0138-auto-warranties-routine-maintenance

 

I'm fairly sure the drive shaft does not turn when in 2wd. Its an open front. Unlock one wheel with add and it free spins through spiders only.

 

Reach under your truck and twist the front driveshaft and see.

 

Waldo, the 4x4's are way different now. Back in the 80's most cars were rear wheel drive. Today almost everything is front wheel. They had 25 years from 1990-2015 to get the cv joints right and use the front and rear wheel drive on the same vehicle. The wheel bearings and hubs have nothing to do with the rotors anymore. I wish there were grease zerks on all the front suspension, but it all seems to work... There are a ton of these trucks with 200k+ and still running strong.

 

Because the parts that do spin constantly in our 4x4 systems are relatively low rpms and low rotational mass.

 

Manual or automatic free wheeling hubs went the way of the Dodo bird many years ago. Very few stock 4x4's use the system except in heaver trucks. I to am old school [very old school] most all 4x4's either had lockout hubs or provisions to add them. Back in the 50's when most every thing had a solid front axle and the lubricants were not the greatest they took a toll on mpg and wear [My 1st 4x4 was a 58 B120 international] got 10 mpg loaded, empty, fast,slow 2wheel or 4 wheel drive didn't matter gas was $0.28 a gallon the 2nd gen Tacoma's while the 4x4 might take a very small hit on mpg the wear is no more than the rear drive and a hell of an improvement over wading through mud up to your ass crack to lock in your hubs.

 

...Well, OK then.....Thanks for the further clarifications!...It all makes a lot more sense now....

..and, yeah...things are way different now than back in the 80s.......4x4s have vastly improved...

...sadly...I have not!.....LOL!.....................Cheers!............B...............

 

I would be willing to bet the ability to unlock the front hubs would gain 1-2 MPG. My last vehicle, an 03 Nissan Pathfinder, had a similar 4x4 system to the Taco. Part-time, shift on the fly with low range. Even had an actual shift lever. One of the most popular and widely debated modifications was to replace the stock hubs with Warns or Milemarkers. Netted most everyone 2 extra MPG's. Never actually did the mod myself... my wheels had too small of a center bore to fit the new hub.

 

1-2mpg sounds about right....2mpg on the very high side. Just look at the EPA ratings. 4x4 and prerunner get the same highway milage.... most people can get ~ 1mpg more in the prerunner vs the 4x4 in real world use... but alot of that could come from the extra weight of the tcase, front diff, and cv's as well as the extra parasitic drag from running in 2wd through the transfer case. The parasitic drag on the front is not a whole hell of a lot.

 

Shoot, I would do it for 1 MPG! lol

 

IF we had hubs that we could put on to make them manual.... the cost you would spend on such hubs could not be recouped for probably 100k miles.

 

If locking front bugs were possible, it would be a simple way to get 2 Low. I know, I know.... there's a mod for that. But I'd rather turn a wrench than cut wires.

 

http://www.tacomaworld.com/threads/511528/