DO's & DONT's 4x4'ing

ultrasonic · 04-22-2005, 01:05 AM

OK I am pretty new to 4x4'ing with my 92' T100 4x4.

QUESTION:
I see when I look on my driver-side sun visor that I MUST lock my hubs when I put the truck into 4 wheel drive. I JUST saw this.

I always thought I could run in 4x4 mode without having them locked?! I've BEEN off roading lately and never locked them. If I dont lock the hubs will my front end just run with unlimited slip? You know the funny thing is that the sun visor also states that you can engage the 4x4 as long as your are doing less than 5 MPH so what am I missing?

Please tell me any Toyota tips that I should obide by with my 4x4 please.

reb · 04-22-2005, 03:32 PM

Without the hubs locked, your truck is not in 4WD mode. The wheels are not connected to the axle.

I think the warning is about running in 4WD, low range with the front axle not engaged and with the hubs unlocked. The concern is possibly applying too much torque to the rear drive components.

My experience has been that you can engage the 4WD at any reasonable low speed as long as the hubs are locked and you are not spinning a rear tire. I always back off the throttle when engaging the front end on the move. Don't try to go from high range to low range on the move, though.

Another suggestion, in case you are totally new to 4-wheeling--don't engage the 4WD on dry hard surfaces. It might be worth your while to browse through the truck division forum threads for general 4-wheeling tips.

ultrasonic · 04-23-2005, 02:03 AM

Yeah I knew that locked hubs "on-pavement" was bad because all the tires spin at slightly different speeds when your driving and making turns. One part that I dont get is when I have hubs locked and I am in the dirt, whats the difference? Sometimes the dirt road conditions change and I am on a patch (lets say) of good firm ground that will grip almost as good as street. Is this just as bad?

What I'm told with 4x4's, even being a new-be, is to stop the truck and engage the 4x4 in neutral. This (I am told) is just safe, good practice -right?

BTW I re-read the visor and it says that any Toyota truck with lockable hubs "must" have the hubs locked in either 4High or 4Low. I wish I could just engage it like the new ford pickups in 4x4 and have limited slip until I actually lock the hubs.

reb · 04-23-2005, 10:09 PM

You have to use your judgment about engaging the front end on hard packed dirt roads. If it is a short distance and you don't have to turn a lot, it is probably ok.

If your tires are all the same size, approximately the same inflation and none are spinning, when the hubs are locked the gears are all going at the same speed. There is no problem in engaging the 4WD on the move. Most 4-wheelers I know do it regularly with no problems. You must stop the truck to shift to low range, however.

If your hubs are not locked in 4High, you are in 2WD, but with the engine turning a bit more of the driveline. Until hubs became popular in the 60's, nearly all 4WDs operated that way. There is no harm to the truck driving it in 4WD mode with the hubs unlocked. However, as I pointed out earlier, operating in low range without the hubs locked can be hard on the drivetrain if you romp too hard on the throttle.

I don't understand how it is possible to have limited slip until the hubs are locked. Locking the hubs generally means connecting the front wheels to the front axle so they can be driven.

hilux5084 · 04-25-2005, 01:48 AM

The hubs lock the wheels to the diff and should be unlocked on sealed roads, the reason being that you then have an increase in the rolling resistance due to the differential action especialy while turning.

Joe

reb · 04-25-2005, 11:14 PM

[The hubs lock the wheels to the diff and should be unlocked on sealed roads, the reason being that you then have an increase in the rolling resistance due to the differential action especialy while turning.]

The only result is a possible slight decrease in gas mileage and maybe a bit more wear on the front drivetrain. There is no point in jumping out to disengage the hubs because you have come to a paved road. Over the life of the truck, you probably wouldn't be aware of any difference in wear if you left the hubs engaged all the time, as long as you follow the rule about engaging the front wheel drive on hard surfaces.

80toy · 04-26-2005, 01:15 AM

if you have manual locking hubs, you need to engage them at the wheel. you can tell by a turn style switch on the hub. my dad forgot to turn his once when he had the 4x4 engaged at the transfer caes (from the cab only) and the pressure in the axle and diff built up and started to back out the drain plug. he had to have his axle and hubs repacked. pain in the ass. if there are no switches on the hubs, then you have automatic hubs, and the only switches or levers you have to engage are in the cab. consult your owners manual if you have it and it will tell you.