4X4 People, Please Help!

[peid]

Ok, let me set the stage as to what I have experienced during my 13,000 miles on my Tundra.

I have an 02 4X4, my first 4X4 ever and too be quite honest, I have NEEDED it once, played with it a lot but only once really needed it.

Like I said this is my first 4X4 and it says in the owners manual that you should occasionally engage the 4X4 to "lube" it up or whatever and keep it functional. So I engage it probably once a month on my straight trip to work on the highway for about 5 miles.

Here is what I experience.

Normal driving (without 4X4 engaged) I cruise/coast at 50mph, let go of the steering wheel and stomp on it. Straight as an arrow!

4X4 driving (with 4X4 engaged) I cruise/coast at 50mph, let go of the steering wheel and stomp on it. Damn near pulls me right into the right hand ditch! I can't go more than 1 second without having to grab the wheel.

Is this normal with a 4X4? Can some other people please try this? I think I am going to go and drive a new 03 this weekend and see if they do it also. If they do, I can live with it, but if they don't I will bring mine into the shop and have it looked at.

[dyogim]

I haven't experienced that yet but, then again I haven't done what you did. Next time I'm on the freeway, I'll see if it does it.

[tundra4towin]

50 mph on a DRY freeway in 4x4! Not for me!!!

The Tundra is not a "All wheel" or “Full time 4x4” drive system. I do not know what the owners manual says about this but I know from previous 4x4's that 4x4 on dry, paved or concrete roads is VERY hard on the entire drive line!

Why?
Because in traditional 4x4 systems the front and rear drive ratio’s are ever so slightly different. The front drive ratio is typically a bit higher so that the front wheels will turn a bit faster than the rear to aid steering in slick conditions. If you have ever had the “4x4 push” you know what I am talking about. When on slick surfaces if you let off the gas a bit and turn the steering wheel not a lot will happen, feather the throttle to apply a bit of torque to the front wheels and they will grab more than the rear. If the front gear ratio was the same, then the rear would continue to push the front forward and not allow it to grab and turn as well.

Another cause for concern is the center differential in the transfer case. On “All wheel” or “Full time 4x4” drive systems the center differential is OPEN so that the power transfer is a path of least resistance to the front and rear. This is just like the open rear differential on our trucks which will allow the wheel with the least amount of traction to get the most power (pretty sadistic if you ask me!). This Open differential is what will allow “Full time 4x4” systems to run at higher speeds with out damaging the drive line.
These open center differentials are what will turn a 4x4 into a 1 wheel drive wonder. Get one of the wheels completely loose and that is the one that will spin and the other 3 get no power at all.

The more sophisticated "All wheel" or “Full time 4x4” drive systems use some type of braking or “Power transfer” system to control which wheel(s) are getting the most power.

Traditionally, the best 4x4 systems have a selectable center differential that can be locked or unlocked. At the very least, it should be a limited slip unit.

As I said this is just general information about 4x4 systems.

As for specifics about the Tundra? Someone on this board drove home with only the front driveline hooked up (rear was removed due to damage) so I will guess that the Tundra has a locked or fixed center differential. My own 4x4’ing experiences point to this as well. Even if it is just a strong limited slip, driving 50 mph on a DRY freeway in 4x4 will stress your drive line in a Big way!!!
Maybe someone else on this board has some more specifics???

If the road is wet, Dirt, icy, snowy, any thing that will allow the front to “slip” a little is ok, but on a dry, high traction surface the locking center differential and slightly higher front drive ratio will cause serious stress on your drive line! The faster you go the higher that stress!

I agree that any 4x4 system should be run on occasion to "keep things lubed", however 20mph on a dirt road will do the same thing and not stress your drive line! Better yet, wait until it rains, find a big, dirty mud bog and have some fun!!!

[DevinSixtySeven]

don't engage your 4wd on dry pavement! at least wait til it rains, or find a dirt/gravel road or parking lot. certainly don't hit the skinny pedal in 4wd on dry pavement.

the pull youre experiencing may be nothing more than one tire (doesn't matter which one) being at a slightly different pressure than another tire. since on a high-traction surface (this even includes wet pavement, if you have good tires or even just siped mud tires) your differentials and transfer case are effectively "locked" (the ground provides the "locker" in this case), if the linear velocity of one tire is even slightly different from another due to a slight mismatch in tire pressure, it will cause a pull to one side or the other. awd vehicles with limited slip center diffs don't experience this due to the center diff...with a locked center, they'll experience the same sort of things we will in 4wd on pavement.

the other thing i can think of is the alignment on the front end, dj might have some input.

dunno if that's the exact explanation for the pull, but it sounds like your 4wd is engaging and disengaging properly (for now...like i said, not on pavement). go find you some trails and work that 4wd mechanism .

-sean

*edit* tundra4towin got it right on regarding the transfer case...ya musta been posting as i typed . tundra is effectively "locked center", it's just a regular t-case.

[dyogim]

I've engaged my 4 wheel drive in dry pavement going straight only and have had no problems. But not freeway speeds on the freeway. Where I see causing problems on dry pavement is when you are turning. Which will cause the 4WD system to bind. After 3 years of doing this, konck on wood, not one problem.

However, Peid, I hope you are not engaging/disengaging the system past the recommended speeds. My suggestion, just make sure you are going straight and there are no turns.

[so40]

peid...

I also try to engage 4 wheel drive once a month to lubricate everything. I usually do this on a gravel road or a woods road. Every now and then I will have to do this on paved roads and I try to do it on a long straight stretch and I do not go very fast or make any turns.

I have not tried what you described in your post. I will try this in the future. However with a standard "open" front diff I would think you would experience a pull like this in 4 wheel drive. The right front is probably doing the pulling and the torque would cause the pull. I am no expert though and I may be wrong. Just about all of my 4 wheel driving is at slow speeds and I do not experience the pull you are describing.

As stated above the tire pressure could do this but it looks like it would do it all the time.

Keep us posted.

[peid]

That is why I precisely said "Let me set the stage" since I knew some would freak out about this.

I drive on a two lane road, not an Interstate or Freeway, but just a country road. Probably see two cars each day, this is not LA, but rather South Dakota!

It is a complete STRAIGHT shot to work on this road and when I get close to the next town I slow down and disengage the 4X4 so when I do need to turn it is only in 4X2.

Now that we have established that I am not turning even the slightest, let me address the "Mudding, Offroading Adventure!" Have you seen my truck? The most offroad it gets is when I miss my driveway and run over the grass! So now that is out of the question. The other is until the past two days, we haven't seen rain in at least 2-3 months, but the past two days we received over 6 inches of rain. My baby was nicely parked in the garage all cleaned up!

So here we are again at the straight, low speed, dry pavement 4X4 problem that I know a lot of people do and never had problems.

My tire pressures are checked weekly before I wash and my alignment is perfect in 4X2, that is why I think something is not right when I engaged the 4X4.

Also, this has been like this since day 1, so it wasn't caused by my dry pavement driving. I just didn't think anything of it before, but since buying it and driving others, they don't seem to do it. Others being Chevy, Ford etc.

Ok, proceed with how dumb my dry pavement driving is and hopefully somebody can tell me if theirs does this or not.

EDIT - Yes I also do stay below the posted 60mph on the visor.

[peid]

I failed to also mention it also does this on icy and snow covered roads, which can get quite interesting to say the least. Cruising down a snow packed road early in the morning and come to an unplowed road and give it some gas before I enter to gain momentum, pulls to the right.

[DevinSixtySeven]

ok, ya got me stumped then

[so40]

peid...

Are you near Watertown S.D.? I have a good friend I was in the service with for 4 years that is from Watertown.

I am going to try to duplicate your problem when I can, but I bet it is going to be a normal pull due to torque (in 4X4) at that speed on a paved road. I assume the steering easily corrects this when you grab the wheel?

I just never have a reason to be in 4 wheel drive at speeds over 30 or so.

[openspaces]

I' ve got an 02 and have experienced this in the tundra and my previous f150. HOwever it was on dirt/tractor paths. The tundra did it most noticably when I tried out 4lo and stomped it. The 98 F150 has also done this in 4hi on the road with snow. However both instances required a heavy right foot.

Others can try this in 4lo on dirt to experience the same condition, but I assume your 4hi on dry is a similar set-up. Just my observations.

Originally Posted by peid

I failed to also mention it also does this on icy and snow covered roads, which can get quite interesting to say the least. Cruising down a snow packed road early in the morning and come to an unplowed road and give it some gas before I enter to gain momentum, pulls to the right.

[peid]

I am about an hour and a half or so from Watertown, SD. Straight north on I29.

I live just outside of Sioux Falls.

I can correct this problem once I do grab the steering wheel but it still pulls even say with the cruise set, not just during hard accelerations. It feels like a strong wind from the drivers side pushing me to the right.

[tundra4towin]

I will second so40's thoughts on torque steer theory. If it only happens when you step on the gas. Front wheel drive cars will act a bit jumpy when you step on the gas so with a V8 on dry pavement it would probably be even more noticeable. I would imagine that the difference in final drive ratio between the front and rear wheels would add to the torque steer as well...
No personal experience though, just a theory...

[GreyTRD03]

I have to agree with tundra4towing, flexing the 4wd at highway speeds on dry pavement is not a good idea. I've owned 4wd trucks, 2 fords and now the tundra, for about 12 years. They all advise to regularly "exercise" the 4wd; ford specifically stated do this in low friction conditions, dirt, rain, etc.

I've never driven a 4wd past 35mph, and don't plan to, so can't say what my tundra does at 50mph. For those of you who said...I'll give it a shot and let you know...I'd be real careful. My brother, a chebbie transmission mechanic, agrees.

My tundra doesn't pull significantly to either side on acceleration in low or high 4wd at speeds below 30mph.