Hey there, I have a 1991 Toyota Truck, 22re. To engage the 4wd on it, it has the hubs you have to get out and manually change on the front tires. Someone told me, if I need to change in an out of 2H and 4H more than a couple times a day, that I can leave the hubs on ‘lock’ between the two. So in theory, I can leave the tires set up for 4WD, but if I need to change in and out, I can just switch the crank back and forth in the driver’s area. Does anyone know if this is okay for the vehicle? I am new to this truck and trying to figure out if that’s alright.
Can’t speak to your truck, but that’s the way it works on my 70’s Ford 4WD truck w/manual locking hubs. When the hubs are disengaged in 2WD the only thing that rotates on the front are the wheels and the wheel bearings on the spindle. But when the hubs are engaged & the xfer case is in 2WD, as the front wheels turn they rotate the front axles and the front driveshaft, but that doesn’t do anything iother than rotate those parts b/c the front driveshaft isn’t connected to anything inside the xfer case. There’s two downsides : first the front axle-shafts and the front driveshaft bearings are being used, which will eventually cause wear, and second, you may notice a change in the feel of the steering and handling, as well as mpg. If you do this anyway, suggest to make all the affected bearings are well lubed. On my truck this includes the front axle shaft u-joints as well, which are a bit of a chore to lube.
Best to avoid the other “hybrid” configuration: i.e. xfer case in 4WD w/the hubs disengaged. On my truck anyway, that can cause problems with the locking hubs.
In addition to causing expensive damage, keeping an old-style 4WD vehicle in 4WD mode can lead to serious safety issues.
In case the OP is not aware of it, his 4WD should only be engaged when he is off-roading or driving in deep snow, and should be disengaged when he reaches “clear” or almost clear pavement.
agree with VDCdriver. or sand on the beach. some older 4wd"s you had to reverse a few feet to make sure it was disengaged. not sure on your vehicle. you can check your owner’s manual. if you do not have one, I am sure you can find it online
That’s not the question, I think. The OP is wondering if they can leave the hubs engaged with the truck in 2WD. I think that’s OK, it just keeps the front axle rotating, slightly reducing mpgs and causing some extra wear, like @George_San_Jose1 said.
When driving my Jeep, I lock the hubs right after I exit the highway so 4WD is ready when I need it. There is no harm in letting the front axles rotate while in 2WD. It would be foolish to wait until the truck is stuck to get out and lock the hubs.
You won’t notice any difference in fuel economy while off-road driving, this is not like a highway trip.
Yes, OK to keep them locked and switch between 4 and 2 wheel drive; and NOT OK to be on pavement in 4 wheel drive. (I had a 1979 Toyota 4X4 and remember.)
Agree with George. The locking hubs are only to ready the 4WD to be engaged with the lever inside the truck that operates the transfer case to select 2WD or 4WD.
With the hubs unlocked, it disconnects the drive shafts to help fuel mileage so it is OK to leave them locked in wintery or off-road conditions so you are ready to shift into 4WD when needed.
I knew a young woman who was permanently hobbled when her Jeep was in a single-car accident. IDK but have wondered if 4X4 on pavement was a factor. Tensions build up in the drive train and can be released by one tire suddenly driving forward at greater speed than the rest. Scary handling.
I have seen a number of SUVs arrive at the shop with the 4WD lock engaged because the driver didn’t know how to switch it off or why the vehicle “hopped” while making sharp turns. Nobody got hurt.
You can leave the hubs locked and put the transfer case in 2WD without any ill effects save for a small fuel economy penalty and some extra wear. For example if you’re driving through snow covered roads in 4WD (hubs locked, transfer case in 4 Hi) and you get to the plowed road, you can certainly just shift the transfer case into 2 Hi and keep going, you don’t have to get out and unlock the hubs every time you shift into 4WD and/or back to 2WD.
On this Toyota truck it will. Most newer 4wd systems it won’t.
I HATED manually locking hubs. First automatic locking hugs I had were on my 84 GMC pickup. Locking the hubs all winter long do any harm it will decrease gas mileage. And sometimes if you leave them locked for extended periods it becomes hard to unlock them.
Most 4wd’s, even the new ones, it can do damage if you drive in 4wd on pavement. All wheel drive systems, you can operate those on pavement. This Toyota doesn’t have AWD, nor do any vehicles with manually locking hubs (that I’m aware of). The difference between AWD and true 4WD is the transfer case. AWD transfer cases (or differentials) have clutches that allow slippage. 4wd transfer cases do not. The front and rear axles are going to turn at the same speed no matter what in a 4wd, therein lies the issue with operation on pavement.
But as for locking the hubs on pavement, it’s not an issue if you don’t put the transfer case in 4wd. I wouldn’t want to leave the hubs locked all the time, though. Not going to break anything, but you’ll get a little unnecessary wear and reduced gas mileage.
4wd vs all wheel drive vs full time 4wd, the lines are kind of blurred recently and the terms interchanged. I guess “full time 4wd” is technically the same as “all wheel drive”? I’d have to Google it to know, myself.
Some 4WD xfer cases include a fore/aft differential. An actual differential, with ring/pinion/case etc. If your vehicle has that type, then you can drive on paved surfaces in 4WD mode. Those types of xfer cases usually use a chain, which I expect is their weakest link. I’d still call those “4WD” vehicles, rather than “AWD”. To me anyway “AWD” means there some sort of clutch or viscous coupling (rather than a true differential) to address the fore/aft problem.
Thank you everyone for the responses about being able to keep the hubs locked, but the transfer case being able to transfer in and out of 4WD. I appreciate the responses and discussion.