I just picked up my 1997 Jimmy today. Paid $2,900.00 and it only has 52k miles on it! Anyways, I was reading the owners manual about 4WD and have a few questions. Do you go mudding in 4lo or 4hi? When its in 4lo, the RPM will go high but the truck doesnt move nearly as fast (you can tell its in 4wd). On 4hi, It doesnt really feel any different with RPM or speed, is this normal or should I jack it up to see if 4hi is working? Also, Will light mud fun,(no ponds or climbing lol) does it put a huge strain the the trans? Would you recommend changing the Tcase fluid since its 11 years old? If so, what would you recommend for it?

 

You would select 4WD high on snow and for easy to moderate off-road (dirt roads, easy trails). You would select it to have better use of traction (better than 2WD) to get going and to maintain forward movement with a reduced risk of slipping and spinning wheels.The added lateral stability of 4WD makes it less likely to slip sideways.

When "4-low" is selected the wheels create substantially more torque-at the same time the vehicle moves at substantially slower speeds

Important: "4-low" does not create more traction - it creates more torque and that can be detrimental when traction is marginal. Slipping tires are more likely in "low" than in "high"!
For that reason 4 low is not a good choice for snow!

Like in 4WD high you still may encounter slipping and spinning tires in 4WD low.Most automatic traction control systems will have a hard time to control that due to the high torque in 4 low. Only "professional" traction control(manual differential lockers)will prevent wheel slip in 4 low. Few have it stock (Jeep Rubicon and Mercedes G-Class) - on many it can be added as an aftermarket option (ARB, Detroit locker etc.)

 

Canyon/Colorado/H3 come with an electric rear locker

H3 Alpha apparently comes with a front e-locker as well.


4LO is an entirely different gear set. Basically only use it when you absolutely have to... I use it more often for precision slow movements because I can fine tune with the clutch, lol.

Otherwise, pretty much only when you're having trouble turning the tires, going up or down steep hills.

Again, only when offroading.

4HI is going to feel the same as 2HI because it's using the same gear ratio. All it's doing is engaging the front differential for offroad.

And if you have 4x4 system troubles, 4LO will actually be a 2LO.

Oh, and don't go fast in 4LO.

 

ok thanks! When I press the 4hi button, I hear the noise of the motor but there is no clunk noise like when i put it in 4lo. Is this normal?

 

Yes, that's normal...

The clunk when shifting into 4Lo is the other gear ratio being shifted into place.

 

Ok, I think Im having a problem with my blazer already, mabey Im just freaking out because its two days old. Heres the entire story, PLEASE let me know anything you know or what you think it might be so I can calm down......
I didnt really know what I was doing yesterday when I put it in 4lo. Somehow, when I put it in reverse there was a loud shrill like an electric motor and a very fast knocking noise(the knocking noise wasnt as loud as the shrill). I then put it in park and it stopped.
Today I went to go test 4wd on a flat muddy field. I put it in 4hi and everything worked great. I waited a few hours and then went back to the same muddy flate feild for some mild sliding around. When I was in 2wd, I slowed down on the road so I could turn into the field. When I made a left turn, I heard that shrill noise. It wasnt nearly as loud as yesterday and sounded like it came from the front of the truck. After that, I continued to coast through the field, when I started to slow down and spin(at very slow speed) I put it in 4hi. about 2 seconds after pressing the 4hi button, the truck made the jerk and popping noisethat 4lo makes. I then brought it to my house and cleaned it up. When I went driving on the road, i put it in 4hi again to see if that jerk would happen and it didnt, 4hi worked fine.

Now, The truck has 50k miles on it. its a 97 Jimmy. Today is the second day of owning it and I changed the trans and t-case fluid. What was the first noise I heard while doing 4lo in reverse? what was the second noise that I heard while turning in 2hi? What was the jerk/pop that I felt in 4hi? Do you think they could all tie in together into one problem? Could I be stuck in 4hi and thats what the turning noise was? I AM FREAKING OUT!!!!!!!!

 

First step to fixing your problem, take a breath. Second step, seek some proffesional help, there are people that can help you.

 

Im calm now because I took a drive and the transmission shifts smoothly in all gears and reverse is fine. What could these shrill noises be? Two different things?

 

For one, I believe there is a thread somewhere on here about proper engagement of 4 wheel drive, have you tried the search feature?https://blazerforum.com/m_59411/mpage_1/key_/tm.htmPersonally, I have mine stopped and in neutral to engage in 4 lo...it will clunk a little when engaging. If you have push button, you can go to 4 hi from 2 hi on the fly 60mph and under. check the link up there.
***EDIT*** I also believe there is a TSB about a front end noise when in 4wd also IIRC

 

I found an old owners manual and already read on how to engage it. I wont ever need 4lo, Just 4hi. Do you have any idea what that "electric motor shrill" could have been when making the turn in 2hi?
Im starting to think that the pop/jerk in 4hi was because i pressed the button while my back wheels were spinning and I think the front had traction so it popped me forward.