"David" <someone@from.dk> wrote in message
news:447de2a8$0$60781$157c6196@dreader1.cybercity.dk...[color=blue]
> [email]davemcc@shaw.ca[/email] wrote:[color=green]
>> To the experienced, this will seem a bit odd, but I'm a bit new to the
>> 4x4 thing and I've been given conflicting information about this so I'm
>> looking for experienced advice..... ;-)
>>
>> I have a 1990 Toyota truck 4x4 5-speed 22RE engine.
>>
>> Can I shift into LOW (4-wheel) range and drive the truck without
>> locking the front hubs without doing any damage? This might be when I
>> want the very slow speed but don't need the actual drive from the front
>> wheels. I know I won't be in actual 4-wheel drive, but what I want is
>> the low speed that LOW range gives me.
>>
>> Also, do I need to take the hubs off LOCK if I shift out of 4-wheel
>> drive in the cab, if it's just for a short distance?
>>
>> I guess the question is if you shift into 4-wheel drive do you always
>> have to trot outside and lock the hubs and vice-versa? Is there a
>> potential for drive-train damage here if you do the wrong thing?
>>
>> Dave
>>[/color]
>
> I can think of two minor issues when driving in "L2".
>
>
AFAIK there is no kind of automatic synchronization (synchromesh) between
> the front axle and the output of the low-gearbox. This means that if the
> car is put in H4 while it is moving, a rotating axle meet a stationary
> axle.. So if the front hubs are not locked, you should only change to H4
> when the car is at stand-still.
> Of course, when the hubs are locked, the rotation of the front and rear
> axles will always be directly or indirectly synchronized, which is why the
> H2<->H4 transition can be made at any (practical) speed.
>
> The other point is a bit more subtle: When in L4 you have an additional
> 2:1 gear - this halves the speed-of-revolution, but doubles the torque.
> This is not a problem when the front hubs are locked in, as the doubled
> torque is distributed across two set of axles. Of course, when the front
> hubs are not locked, in the rear axle experiences the doubled torque. I
> don't know for a fact if this is a problem, but I would be careful when
> driving in "L2" (i.e. no off-roading or trailer-pulling).
>[/color]
The gear ratio in LO Range is the same whether the front hubs are locked or
not. There is no problem at all, if one wants lo speed, high torque, and 2WD
with only the rear wheels getting power.
My Jeep has the ability to engage 2LO in FWD only, the OP wants his 2LO to
be RWD. No problem at all. Offroading and trailer pulling is the most common
time when 2LO will be desired. No problem.