Front Locking Hubs

GA Pete.

I would've put it a little more simply like this:

Converting an AWD into a RWD vehicle with locking hubs on the front wheels can be done with a sound knowledge of mechanical engineering. You will not gain that engineering knowledge from visiting any generic engineering discussion forum. If this has already been successfully done on a Hummer you might find out the fine details at a Hummer discussion group. Regardless of which forum you find information on this conversion I recommend you find a local off road conversion shop to do the actual work. They will have the equipment and expertise to evaluate if your specific vehicle is a good candidate for this conversion.

GA on both counts so far. All locking hubs do is prevent wheel spin. The automatic system you have leaves the hubs unlocked (which is your stated goal) until you need the traction and then the hub automatically locks up (automotive engineers are such smart people!!). If you want better fuel economy, look to other things such as driving style, the bus or your bicycle. To improve your fuel economy significantly, it will cost you some serious dollars and at that time, maybe you should just invest in a newer more fuel efficinet vehicle.

Unless you have a RWD position on your transfer case lever (or solenoid's console switch) then you gain/save nothing at all.

As this is an AWD (ie permanent 4x4) vehicle it may not even have mode selection.

If you want to save gas then get a smaller car. If you want the ability to decide when 4x4 is working then get a another truck.

I drive a 4x4 Ford Ranger. It has manual free wheeling hubs but I leave them locked all the time so i can slip in and out of 4x4 without having to get out of the car. Also good for highway driving here where you transition from sealed to dirt to mud to sealed all the time. I need 4x4 to get into my garage when it is raining. Tiled floor gets slippery when wet. Again just pull back the lever and go. No need to get out of the car.

I have done fuel economy caparisons with hubs locked and unlocked and it doesn't change.

Of course if you enjoy some fishtailing, opposite lock action then I understand where you are coming from. Enough power there to have a hoot.

I have never worked on a Hummer but on a 80 series land cruiser all wheel drive it has a centre diff & when the front wheels spin without a load it doesn't get any drive on the back, you have to lock the centre diff to drive the front & back wheels constantly. I remember when we first bought the Toyota & got really stuck in some mud. The front wheels spun continuously & the back stopped turning until we locked the centre diff & forced both front & rear to drive at the same time.

I believe this is what would happen if you fitted manual locking hubs to the front of your vehicle & unlocked them, the front diff would spin & no drive on the rear unless you lock the centre diff.

As others have said there are possibly many problems you could cause by fitting manual hubs to your vehicle it might cause more problems than benefits. I think the all wheel drive is excellent as it makes for really good handling under power when avoiding other idiots on the road.

Hummers are notorious gas hogs as it is, I can't imagine why they would make them permanent AWD in the first place. What a revolting development that turned out to be.

I have a four wheel drive Kia Sportage. There came a time when I really needed that four wheel drive and by the way, the Kia isn't all that good getting over bumps in two wheel drive, they are fine on flat roads. The automatic four wheel drive wasn't setting and had to be pulled out. Found that the supply to the automatic hubs was gone, I don't think Kia's are very good design, they are a hassle even to changing spark plugs. At least I know I can change out the auto locking hubs for manual and the manual locking hubs only cost $135 and are easy to install.

AWD Hummer, with today's gas prices, I call that irresponsible designing.

It's true the H2 is a gas hog...but their "latest" innovation in AWD is *better* on fuel consumption.

There is a good write-up on the Hummer site describing how their version of AWD works.

Given the cost of a Hummer and necessary bank account to fuel it I would suggest just buying a Two wheel drive truck of your choice and save yourself a big headache. From what I have read, and seen at mud bogging Hummers do not "Customize" well other than appearance items. just my observations.

Thank you. Sort of restores me desire to get one.

If you have an auto locking drive system, and remove the self locking hubs, the transfer case will need to be placed in diff lock to prevent all drivivg torque from just turning the front driveshaft, and spinning at the disconnected front hubs. If your Hummer has wide tires on it, it may see some gas mileage improvemert with the hub conversion. Try looking for some Hummer specific web sites for more specific answers. The sensors for ABS and traction control are monitoring the speed of the front rotors, so these functions shold remain opperational. There are other things that you can do that will help mileage. Going to a taller tire should help. Actually, by going to a higher aspect ratio, can help in two ways. The tire will cover more ground per revolution. In addition, the narrowew tire shuold have a lowew rolling resistance. If you go from a 60 series to a 70 series, you should gain. If you do not work the truct to hard with towing, heavy loads or hilly driving, you could also go to a numericly higher number tire, like going from a 265, to a 275. Looking in your owner's manual and the Hummer sites for the tallest tire that will work on your truck. If you vary too far from OEM tire size, the vehicle's computer may need reprograming. These may also help you gain mileage. Good luck.

Probably, but if you are trying to save money on gas isn't this just a band aid solution that will cost a lot to implement but only save you a very small amount of money over time?

Have you considered switching to a more fuel efficient vehicle (if fuel cost is really your motivation in this case)?

Yes you can. It requires the replacement of the transfer case, transmission, and other components. Predator Motorsports can do the work, and slip in a Duramax engine at the same time which, depending upon state of tune, can change your fuel efficiency from incredibly awesomely awful to just horrible awful.

Installing locking hubs alone would gain you nothing. You can see the problem in this cutaway view of your transfer case. The front driveshaft and differential would always rotate, regardless of whether the transfer case is in AWD or 4 hi locked.

This can be done very EASILY. First of all the tcase front 60/40 planetary has to be removed and replaced with a special coupling. This change is a single part and all tcase functions remain the same with the exception being the AWD mode is now 2WD. Next the RamManInc.com builds the front locking hubs for the H2. I have performed this conversion on my H2 and it performs flawlessly! For more info I can be contacted at chivelry@aol.com