CarSPIN Forums

Auto Talk => The Big Guys => Topic started by: Rupert on December 13, 2005, 03:40:57 AM

Title: Stupid question
Post by: Rupert on December 13, 2005, 03:40:57 AM
In my truck, which has power steering and auto-locking hubs, how can I tell when it's out of 4WD? The manual says to back the truck up for 15 feet (which I do, obviously). Problem is, I can't feel any difference between four-high and two-high in the steering. I've thought that there might be a gearing difference, where the rpms would be different at the same speed and gear depending on if it's in four-high or two wheel drive. Should that be the case?

On a totally unrelated note (:lol:), the manual says to not exceed 55mph in four-high. What happens if I do? (And is it because of a gearing limit, or something else?)

Thanks, oh people of more four-wheeling experience.
Title: Stupid question
Post by: giant_mtb on December 13, 2005, 04:59:53 AM
In order to tell if it's in 4WD or not, I'd say look at the 4WD gearshift...but that's just me.  :blink:  
Title: Stupid question
Post by: cawimmer430 on December 13, 2005, 07:12:06 AM
On our ex-1996 Mitsubishi Pajero SUV, the manual said not to shift into our out of 4WD at speed over 100 km/h (62 mph). I did it anyway a few times (at speeds of around 110 km/h) and nothing ever happened.

Does your truck have a display lamp? Our Mitsubishi had a little lamp which told you if the car was in 2WD (RWD), high range 4WD, 4WD with high range locked center differential and 4WD with low range locked center differential.  :lol:  B)  
Title: Stupid question
Post by: Raza on December 13, 2005, 08:39:33 AM
Now Psilos, there are no such thing as stupid questions.

But there are a lot of inquisitive idiots.
Title: Stupid question
Post by: 93JC on December 13, 2005, 10:03:37 AM
QuoteIn order to tell if it's in 4WD or not, I'd say look at the 4WD gearshift...but that's just me.  :blink:
Doesn't mean jack.

QuoteProblem is, I can't feel any difference between four-high and two-high in the steering. I've thought that there might be a gearing difference, where the rpms would be different at the same speed and gear depending on if it's in four-high or two wheel drive. Should that be the case?

You shouldn't be able to feel any difference in the steering, nor will your engine rev any differently than in 2WD (4 High is a 1:1 gear: your revs stay the same).

You should be able to feel the difference based on the general handling changes 4WD induces. The truck will seem far more surefooted (very little slip slidin' around compared to 4WD). You should be able to hear a slight droning noise from the front axle when you're in 4WD, which will go away in 2WD.

QuoteOn a totally unrelated note (:lol:), the manual says to not exceed 55mph in four-high. What happens if I do? (And is it because of a gearing limit, or something else?)

It should say not to shift in and out of 4 High over 55 mph. The reason for this being the sudden forces applied to the drivetrain could exceed the stresses the parts were designed for (i.e. there's a better chance you'll break something).

Title: Stupid question
Post by: giant_mtb on December 13, 2005, 01:23:41 PM
Quote
QuoteIn order to tell if it's in 4WD or not, I'd say look at the 4WD gearshift...but that's just me.  :blink:
Doesn't mean jack.
...and why not?  :blink:  Is that like saying just because the gear-shift is in D doesn't mean it's in Drive?
Title: Stupid question
Post by: Run Away on December 13, 2005, 02:32:32 PM
Rev the engine to redline in neutral, then drop the gearshift to D.

If 4WD is engaged, all four wheels will spin.
If it's not, only the rear wheels will spin.

It always works.
Title: Stupid question
Post by: ro51092 on December 13, 2005, 03:03:36 PM
That's gonna screw your tranny
Title: Stupid question
Post by: Rupert on December 13, 2005, 03:03:42 PM
93JC- But what if I shift out of 4WD on pavement? It won't be slippin and slidin then...

GMTB- Even with the idiot light, and the labeled gearshifter, 4WD doesn't disengage until you follow the proper procedure. (In my truck, and most, I think, that's backing up for a few feet). That means that the 4WD light can be off, and the lever out of 4WD (in fact, the light goes off when the lever is moved out of 4WD), but the truck can still be in 4WD. I think it'd be nice if the light didn't go off until it was outa 4WD, but no such luck.

Run Away- See, I like my transmission. If I were gonna (try to) burn out, I'd put it in D, put my left foot on the brake, rev with the right, then release the brake. :lol:
Title: Stupid question
Post by: giant_mtb on December 13, 2005, 03:05:58 PM
Hmmm I've never heard of having to travel in R to make sure that you're out of 4WD...  :blink:  :ph34r:  :P  
Title: Stupid question
Post by: Run Away on December 13, 2005, 03:07:43 PM
QuoteThat's gonna screw your tranny
Have you tried it?

How do you know?
Title: Stupid question
Post by: El Barto on December 13, 2005, 04:02:17 PM
Quote
QuoteThat's gonna screw your tranny
Have you tried it?

How do you know?
I think he should try it and find out.   :P   And record what it does then post the vid here.   :P  
Title: Stupid question
Post by: Tom on December 13, 2005, 04:37:34 PM
QuoteRun Away- See, I like my transmission. If I were gonna (try to) burn out, I'd put it in D, put my left foot on the brake, rev with the right, then release the brake. :lol:
I don't think that is bad at all. It's just brake torqueing.  People do it all the time with no problems.   A neutral drop is far worse.  
Title: Stupid question
Post by: Tom on December 13, 2005, 04:39:27 PM
Quote
Quote
QuoteThat's gonna screw your tranny
Have you tried it?

How do you know?
I think he should try it and find out.   :P   And record what it does then post the vid here.   :P
I'm sure that's not good, but I really doubt that would break/burn out a tranny unless done a lot.  Hell, I accidentally put my car in park while moving 20mph the other day and it's good as new :)  
Title: Stupid question
Post by: Rupert on December 13, 2005, 04:52:55 PM
GMTB- It's not to make sure it's out, it's to get it out of 4WD in the first place. I'm really just asking how I can make sure it's out.

Tom- Yeah, that's what it's called... Brake Torqueing. I was saying that, if I wanted to spin tires, that's what I'd do.

I don't think one or two neutral drops will fuck the tranny right then, but it's needless wear and tear.
Title: Stupid question
Post by: Tom on December 13, 2005, 05:06:17 PM
QuoteTom- Yeah, that's what it's called... Brake Torqueing. I was saying that, if I wanted to spin tires, that's what I'd do.
Ohhh, for some reason I though when you said "burn out" you mean if you were trying to burn out your tranny(for some reason).
Title: Stupid question
Post by: 93JC on December 13, 2005, 05:28:58 PM
Quote
Quote
QuoteIn order to tell if it's in 4WD or not, I'd say look at the 4WD gearshift...but that's just me.? :blink:
Doesn't mean jack.
...and why not?  :blink:  Is that like saying just because the gear-shift is in D doesn't mean it's in Drive?
Shifting the transfer case back to 2WD will unlock it from 4WD, but the vacuum actuator at the front axle still has to disengage the axle in order to return completely to 2WD.

If there's a malfunction in the vacuum actuator (not all that uncommon as far as 4WD problems go: usually the first thing to go wrong with any automatic 4WD system) you could shift the transfer case back and forth between 2WD and 4WD to your heart's content and it wouldn't do a damned thing.


(And, yes, if your automatic transmission's shifter is out of alignment you could potentially have it in another gear while indicated 'D'.)


If you really really really really really really cannot feel the difference between 2WD and 4WD (which I find incredibly hard to believe on dry pavement), try turning around in a circle. Your drivetrain will be screaming for mercy as the stresses build from having the transfer case locked in 4WD. You'll experience what is known as "binding", manifesting itself as "tire scrub" (the tires will break traction in order to complete the turn). It will fuck your truck up good if you pull a tight enough circle, but you'll know you're in 4WD.  :ph34r:
Title: Stupid question
Post by: Rupert on December 13, 2005, 05:34:28 PM
Even with open diffs?
Title: Stupid question
Post by: 93JC on December 13, 2005, 11:05:11 PM
Yeah.

That is, assuming you have part-time 4WD. I'm not too sure whether Troopers of that age did or not, but from your wording of your earlier posts I'm guessing so.
Title: Stupid question
Post by: Rupert on December 14, 2005, 02:33:15 AM
Interesting... I guess I'll go on the assumption that it's out after backing up 15 feet or so... (Until I can better tell the difference by feel).

And, yeah, I've got 4 High, 4 Low, and 2 High.

Oh, btw, is that sig quote from Achewood? Sounds like something Ray might say...
Title: Stupid question
Post by: SargeMonkey on December 14, 2005, 05:47:52 AM
With our truck you lock the hubs and shift the transfer case into low or high. No backing up. Origanaly these things had a chain system that kept it in 4WD full time, the guy who owned it before us added warn hubs and removed that chain thing.
Don't shift from high to low while moving, it very bad, also avoind pulling a stuck truck out of mud in High, it will blow your transfer case. My dad did it to a 80 blazer, sold it that way. Person didn't try to shift it into 4WD when he bought it.
Title: Stupid question
Post by: 93JC on December 14, 2005, 08:49:11 AM
QuoteOh, btw, is that sig quote from Achewood? Sounds like something Ray might say...
Trading Places. Eddie Murphy, shortly after having switched places with Aykroyd.  
Title: Stupid question
Post by: SVT666 on December 14, 2005, 01:58:16 PM
QuoteHmmm I've never heard of having to travel in R to make sure that you're out of 4WD...  :blink:  :ph34r:  :P
Virtually every 4x4 made before the mid 90's required you to back up a minimum of 10' to completely get out of 4x4.  If you didn't do it, then your drivetrain would be humming real loud at 55mph or higher.
Title: Stupid question
Post by: 93JC on December 14, 2005, 02:04:11 PM
My Jeep doesn't. :praise:
Title: Stupid question
Post by: Rupert on December 24, 2005, 04:24:58 AM
1993 is totally mid '90s ;) .
Title: Stupid question
Post by: 93JC on December 24, 2005, 10:56:33 AM
1995 is totally mid-'90s. 1993 is early-to-mid-'90s.

Not that it really matters: an '84 Cherokee didn't need to either.  ;)  :praise:
Title: Stupid question
Post by: Raza on December 24, 2005, 12:17:35 PM
Early:  1990-1993
Mid: 1994-1996
Late: 1997-1999

Kind of like the grading system.
Title: Stupid question
Post by: Rupert on December 24, 2005, 04:16:33 PM
Fa!
Title: Stupid question
Post by: Run Away on December 24, 2005, 06:30:44 PM
lalalala, lala la la?
Title: Stupid question
Post by: sparkplug on December 24, 2005, 09:34:20 PM
My dad had a 1995 Ford F150 4x4. He never read the owner's manual. I don't why but I know he never did like to read. His method of getting the truck out of 4X4 was to stick it in reverse and snatch it out of 4WD. I read the owner's where it said the change from 4wD to 2WD put it 2WD and change direction from forward to backward or backward to forward.

I am glad the new ones or different or I'd probably have to read the owners
manual again to him.

The question isn't a stupid question. If you try to turn a 4WD truck while it is engaged in 4x4 mode on the highway it will be tough to turn. It'll also have some vibration in the drivetrain but most of all it'll drive kind of funny uhoh, not funny haha.

Title: Stupid question
Post by: saxonyron on December 25, 2005, 11:17:30 PM
You would know it if you turned the wheel sharply at slow speeds.  If 4wd was still engaged, you'd hear your inside front wheel hopping or skidding.  Also, at speed going straight, you'd feel a drivetrain whine and/or drag.