Engaging 4WD.....how often should you do it?

[Brigadier]

In March I bought my first 4WD vehicle - 06 Colorado. My previous vehicle, 1990 Astro, was full time AWD.

I have been told you should shift your 4WD vehicle into 4-hi now and then to keep things lubricated. Is there any validity to this? I have been shifting it into 4WD about once a month, on a rainy day, while driving in the city so speed is not above 40 MPH, for a mile or two.

TIA.

 

[Schmoe]

I think it would depend on what kind of system you have. I have full time locking hubs and only activates inside the gear box, so I don't worry about it. If you have a external vacuum assist lock, not full time axles turning, like the newer fords have, I'd check it about once a month to make sure it actually works. Would suck if you need it and nothing happens.

 

[JTK]

Having owned several 4x4's with electronic shift on the fly actuators (and living in the rust-belt), I can attest that this is beneficial. The mechanical actuators that spline the front axle into one can get moisture in them and corrode in place if you don't use them.

What I used to do is engage 4x4 as I pulled out of my driveway, once my wheels were straight. Before I hit the turn ~100 yards away, I'd turn it off.

Locked up actuators were common on my 2002 Isuzu Rodeo.

 

[Bgallagher]

Originally Posted By: Schmoe
I think it would depend on what kind of system you have. I have full time locking hubs and only activates inside the gear box, so I don't worry about it. If you have a external vacuum assist lock, not full time axles turning, like the newer fords have, I'd check it about once a month to make sure it actually works. Would suck if you need it and nothing happens.


+1 I believe you have external vacuum. Worth putting it into high (and possibly low) once a month to make sure it works. Takes less then a minute and worth it!

 

[INDYMAC]

My 2000 Tundra owner's manual says to engage it at least once a month for 10 miles to lubricate and protect internal components. When it's not hunting season, I try to pick roads that are relatively straight if the surface is dry and limit my speed to 55MPH max. Dry roads can cause binding and possible damage while turning. If you drive on snow, mud, gravel or loose dirt roads, turning will not be a problem because the tires can slip instead of binding the gears while turning.

I'm not familiar with the Colorado system, but maybe the owner's manual will enlighten you. Do you have one?

 

[Brigadier]

Yes, I have the manual. It does not mention anything about shifting into 4WD occasionally for maintenance purposes.


Originally Posted By: INDYMAC
My 2000 Tundra owner's manual says to engage it at least once a month for 10 miles to lubricate and protect internal components. When it's not hunting season, I try to pick roads that are relatively straight if the surface is dry and limit my speed to 55MPH max. Dry roads can cause binding and possible damage while turning. If you drive on snow, mud, gravel or loose dirt roads, turning will not be a problem because the tires can slip instead of binding the gears while turning.

I'm not familiar with the Colorado system, but maybe the owner's manual will enlighten you. Do you have one?

 

[JHZR2]

I was under the impression that everything in the front diff turns unloaded in 2wd, do you're not going to have a dry and rusty front diff.

I always figure that a little load makes a little heat which is good. Front diff fluid is usually nasty.

 

[Bgallagher]

Originally Posted By: JHZR2
I was under the impression that everything in the front diff turns unloaded in 2wd, do you're not going to have a dry and rusty front diff.

I always figure that a little load makes a little heat which is good. Front diff fluid is usually nasty.


The diff and transfer case would be OK, it is the hubs that I am more concerned about. Unless they are perminantly engaged they would not get the same lubrication like the splash lubed diff

 

[JTK]

Originally Posted By: JHZR2
I was under the impression that everything in the front diff turns unloaded in 2wd, do you're not going to have a dry and rusty front diff.


That's true for your typical solid hub system that makes/breaks the front axle with a SOTF actuator. It's basically a mechanically actuated shift fork on one side of the front axle that slides a splined collar to make the hole thing live wheel/wheel.

 

[calvin1]

Almost nobody uses part-time hubs anymore. Ford does but only on the SD, not sure about Jeep. It's still a good idea to run the 4x4 every month or so to make sure the engagement pieces don't seize. However, that aside, rain covered blacktop is NOT slick enough for safe 4x4 operation. You need to find a gravel or dirt track you can use instead.

 

[Zaedock]

Originally Posted By: Bgallagher
The diff and transfer case would be OK, it is the hubs that I am more concerned about. Unless they are perminantly engaged they would not get the same lubrication like the splash lubed diff


Most 4WD vehicles these days run unit bearings. Even the older live spindle lockouts always have the grease circulating in the bearing when you move in the unlocked position.

 

[Astro14]

My Toyota OM says once per month for 10 miles. If I don't take the truck in the sand or off-raod that month, I do it at low speeds, on a straight road to minimise stress on the system when I do it.

In this system, the front driveshaft doesn't turn, though the front axles and hubs do, when in 2WD...so I think the only thing I am exercising by engaging 4WD is the transfer case and the front driveshaft...

On a newer truck like yours - I would do the same thing, unless the OM has specific guidance. Just enganging/disengaging the solenoids and gears helps keep them from sticking in the future, when you really need the 4WD...

 

[SwampSurvivor]

I was under the impression that you aren't supposed to run the lockouot hubs on the superduty always locked? I guess the differential wasn't made for the constant spinning?

I have solid front axle shafts (no lockouts; always engaged) and I go wheeling with the cherokee every few weeks. My 4wd gets used.

I'm not entirely sure I trust the electronic systems ...

 

[dave1251]

I do not have a recommendation. I will engage 4x4 system at least 3-4 times a year and will test it before I take my truck into a situation where 4x4 will be required.

 

[Shannow]

Originally Posted By: INDYMAC
My 2000 Tundra owner's manual says to engage it at least once a month for 10 miles to lubricate and protect internal components. When it's not hunting season, I try to pick roads that are relatively straight if the surface is dry and limit my speed to 55MPH max. Dry roads can cause binding and possible damage while turning. If you drive on snow, mud, gravel or loose dirt roads, turning will not be a problem because the tires can slip instead of binding the gears while turning.


Doing that, the system will "wind up", due to any variances in tyre diameters etc.etc., to the point that one of them will start to slip. This is the maximum torque that can be applied through the drivetrain.

Then add speed (55MPH), and torquex speed is power. You will have the equivalent power being circulated through the drive train as if you were doing a 55MPH indicated burnout. The engine only has to add enough power to overcome the frictional losses in the system.

As far as the diffs are concerned, that's a 12 minute burnout,at an indicated 55MPH.

 

[Shannow]

Originally Posted By: JHZR2
I was under the impression that everything in the front diff turns unloaded in 2wd, do you're not going to have a dry and rusty front diff.

I always figure that a little load makes a little heat which is good. Front diff fluid is usually nasty.


All of my 4WDs have had manual hubs. Thank goodness this is Oz.

With the manual hubs, nothing turns when in 2WD. Worried about brinelling etc, I run them "locked" a couple of days every few months, and in winter locked maybe for 3 months (saved us last year when we had to rescue daughter on a school excursion that got snowed in, I didn't have to go skating to lock them in).

Summer, I often leave the hubs unlocked, and just engage 4Hi on the transfer case to spin the diff.

80,000 km, and 9 years on, the M1 gear lube drained out looking like new.

Driving with the hubs locked (or with splines like are mostly used in the US/Japan these days), you are driving the drivetrain with the back side of the teeth, not the load side...it ain't natural.