Review of Bomb's Visco Lok Differential

[MtnOuty]

Northern Bomb Man wrote:

Quote:

The 4x4 on all outlanders uses an acuator motor and small diameter pin to engage 4x4. When you select 4x4 on your switch, the solinoid takes power from the battery and sends it to the act. motor. YOU DO NOT want to switch from 2x4 to 4x4 on the go, at a slow speed or anything but a complete stop! If you do this repeately, then you will sheer off the pin that engages 4x4 and be without 4x4 till you take the machine to a dealer ( act. motor costs about $684.00 CAN BTW!

This pretty much settles the question imo. Is there much chance of shearing when engaged properly, then going in and out of 4wd depending on conditions of engaging, then disenengaging under slippery conditions?

[outlandish]

To me it's not a big deal to stop and engage it. I can see if something ahead looks questionable and I stop and switch it in before diving into it. It's much easier to do it beforehand than to stop once stuck in 2 wd.

I know a lot of guys say "as long as your not on the gas" you can switch it but why take the chance?

[JimJa43]

Does
anyone have a breakdown picture of the Visco-Loc?Â* I'd like a good picture
of the internals.Â* Although this is described as a "pump," I'm
thinking this is not a pump in the conventional sense.
Â*
When
they say, "shear" for the silicone fluid, then one part of the
"pump" is mechanically connected to one wheel via the axle, and the
other part of the "pump" is connected to the other axle, or input shaft.Â* When
there is a speed difference between the two axles, the fluid makes a dramatic
and rapid change, getting very "thick."Â* This somehow, either
directly, or indirectly via a set of pistons (I believe this is how they said
it was done), pushes the clutch pack together, equalizing the torque between
the two front axles.Â* To say the torque is "transferred" to the
wheel with the least traction is somewhat of a misnomer, the torque is equal
between the two, increasing on both until the "resistance" on the
wheel with the most traction is overcome and the wheel moves.Â*Â*
Â*
I doubt
very seriously if a retro "kit" could be developed to lock the
differential.Â* A direct, and movable mechanical connection between the two
sides would need to be made (like a spline).Â* I would sure like that
ability however.
Â*
A more
likely possibility might be to change the diameter of the "pistons"
that push on the clutch pac, causing the same amount of pressure to exert a
greater force.Â* This would also result in a quicker engagement.Â* This
too would require an engineering fix since that would change the piston
movement distance.Â* Simple in theory, expensive in execution.

[Redrox]

3 years and 2500 miles on my 400. Made the transition from 2 to 4 too many times to count. Never had any problems-shear pin or otherwise. Again, just backed off on the throttle and actuated the switch, waited about a second a put the throttle to 'er again.

I did however try making the switch underload once when I inadveretantly got into some wet sand that surprised me. Engaged with a serious "kuchunk". Had me worried but never did lose any functionality.

I also got into the habit of making the change between low range and hi range on the fly, albeit at slow speeds. If you caught the revs just right it was a smooth transition. Got so good at it after a while that it became routine.

Benched the 400 now with 1 month left on the warranty. Just saddled up the 800. This thing is a beast! Having to relearn to ride with this kind of power at my thumb tip.

Redrox

[Newfie400XT]

Redrox can you give more info on changing from high to low on the fly, I would like to know how to do this properly and dont want to expiriment and damage anything. Can you go from high to low on the fly to.

As for the engaging and disengaging the 4 wheel drive, my dealer told me that as longas all four tires are spinning at the same speed it won't damage anything.

[OSOKILL]

Newfie400XT wrote:

Quote:

As for the engaging and disengaging the 4 wheel drive, my dealer told me that as longas all four tires are spinning at the same speed it won't damage anything.

Everyone else and I mean EVERYONE has said STOP before locking in the visco or you can mess it up ("grenade it"). so it prolly wouldnt hurt to kinda ignore what the one"dealer" said till we hear more from the other service managers we have here at AWF

[Newfie400XT]

Thanks for the advice, I've been hisitant while doing and still most of the time stop the change from 2 to 4. Only during low speed travel on roads and trails is when I changed on the fly. My dealer is new to selling ATV's so his advice might be a little off. I'llhave towait for confirmation before I do it again.

[Redrox]

Hey Newfie. I am not advocating switching back and forth between 4wd and 2wd on the fly as I would not want to feel the guilt if your machine did pile up. However I will continue with my own without any great concern.

As far a shifting from low range to high without coming to a complete stop. No secrets to this operation, just have to get a feel for the rpm. Saves a bit of time if you come out of a tight trail onto a smooth straight run and don't want to eat your buddies' dust.

I always come to a complete stop when going from high to low.

I am probably not the easiest guy on riggin' as I tend to ride 'em hard and put 'em away wet. However my 400 seemed to be up to the challenge. The new 800 still hasn't had a full workout as I am relearning to ride with all this power (have been upside down a couple of times).

[Newfie400XT]

Thanks Redrox, I'll try it at my own risk.

[canambob]

that was a great treatise on visco lok,
please do the same on 4wd and the switches and actuators
testings and usual customary failures, for this
seems to be a popular failure with high questions,
also where is a canam junk yard, i need the boot for the 4wd switch?
there ought to be a video on this repair, if i knew how or what i was doing, i'd make the repair on youtube?
and keep it simple??K.I.S.S!
my machine(2005, 400cc, OUTY ) first time out for this used machine, i thought i was beating IT! no no, it surely beat me, i'm so sore...

LOL