4WD prob

[Slacker1357]

I was always tryin to figure out why my 4wd won't work and I think my problem is bigger than a simple vaccuume prob or switch.

I have a feeling it might be a front wheel hub.
Monroe gave me a god aweful quote of $48_ something...
I went to Pep-boys and got a quote of around $200 something

Monroe also wanted to do all 4 ball-joints for around $800... F that
Pep-boys around $400. All in all... off-roading is expensive fun... that or driving around the pot hole ridden streets of Buffalo

I now know my trusty buddies at monroe have skipped dinner and are now raping me. I'll leave simple tire stuff and basic maintenance to them... but bigger sh*t?... I'll drive 3 mins down the road to someone else.

feel free to add anything or ask questions.

[j894]

the Front 4x4 system is pretty simple.
I don't know if it would be the hub assembly. All it does is mount to the steering knuckle, and the CV shaft goes through and is bolted to it.

It is most likely a broken actuator, vaccum line, or the motor in the transfer case.

When you put it in 4x4. Reach underneath the truck and try turning the front drive shaft does it turn?

[T Man]

yes, the hub isnt like the old style locking ones. Its more of a splined carrier bearing (for lack of a better example), if your bearing was that bad, your wheel would be parked beside your tripod truck

[Mikz86TA]

Im in the wrong business. hehehe I just found out my neighbor with a 97 Bravada he has had since new, paid $600 for the radiator to be replaced. Just a rad and coolant, no hoses or anything. I wouldve done it for much less.

[Jongo88]

Looks like about a $450 in the bank. He got ripped:mad:

[Blazer69]

exact example why i do all my own work....lol

[Tink]

Yikes! I don't have a shop do ANYTHING but Inspections. I actually remove my rims and tires and put them in the back of one of the pickups and drop them off the have new tires mounted and balanced.

Anyhow, what are the symptoms of your 4wd problems?

[Slacker1357]

I push the 4wd Hi button, hear a click from the button and it lights up... no front tires move. I had some mechanics shake some **** down and found that my ball-joints were going and something about a bearing and something about the front Hub assembly.

[Jay-Sliver]

Um..well..ur "front hub assembly" IS your wheel bearing, its not going to have anything to do with your front wheel drive not working. Ball joints, again, not an issue with the 4 wheel drive working. Most likely what has happened, is the actuator isnt..actuating..
Wait..do you have, or are you pushing the Auto 4WD Button? May be a stupid question, but..

[Jay-Sliver]

wait..nvm...i re-read and your saying your pushing your 4hi button..
ok, push it, leave ur door open, lean ur head out the door...when you push the button, you should hear the actuator...do ya hear it?

[C4Tom]

BUMP.... well Roger?? do your hear it?? LOL

I may be experiencing 4WD issues... I'm interested in seeing how this thread goes....

[Blazer69]

see i have the same problem...my actuator engages the transfer case abd the front driveshaft spins but no tire spin?????

[Slacker1357]

Im sorry guys/gals... I've been in Ft. Drum for the past 3 weeks. give me a day or two to check up on the 4wd again. But thanks you for checking in and helping me trouble shoot. I dont go out very often and I may be partying it up for a day or two... singles party including some people in the military... kind of a welcome back from a stressful AT...

I only hope for the best night :D

[C4Tom]

I noticed that none of the lights were on in the switch. So I pushed 2HI and the light only came on when the button was pressed, upon release no lights again. I pushed 4Hi, light on release light off.

Yesterday, I decided to go through all the gears to see if it was all fully working. I shifted to neutral and pushed 4LO, it clicked, clunked and lit up 4LO button light. I shifted into drive and felt a ton of LO gear torque.... muhwahahahaha... love torque!

I shifted back to neutral and pushed 2HI. I once again heard the click, clunk and the 2HI light came on. I shifted into drive and the light stayed on. I drove it today and the light is still on!

So, instead of a problem, did I have a glitch on the cpu? Cycling through the gears just allowed it to fix itself? Tink? Whatcha think??

[TreasonAgainstCaesar]

I shifted back to neutral and pushed 2HI. I once again heard the clicking, clunk and the 2LO light came on. I shifted into drive and the light stayed on. I drove it today and the light is still on!

Tom, check your story, I think you may have typo-ed some stuff there... 2HI, 2LO..... Did your 4HI work in the end?

[C4Tom]

Thank you... story corrected! :D I never thought to check 4HI... doh! I'll check that tomorrow. Oh yea... and what should I expect or see or hear when I push AUTO 4WD??

[TreasonAgainstCaesar]

Auto 4WD is for driving in conditions where you may need 4wd. Like if it was slushy out. The 4wd would kick itself in when it feels wheels start to slip. At least that's how I understand it. My blazer doesn't have it, but I'm not a big fan of the idea.

[Tink]

I push the 4wd Hi button, hear a click from the button and it lights up... no front tires move. I had some mechanics shake some **** down and found that my ball-joints were going and something about a bearing and something about the front Hub assembly.

Most likely it is something with the vacuum actuator. The transfer case is changing position, but the front axle is not engaging. Ususally though, it takes an extended time for the indicator lights to come on. Could also be the vacuum switch on the transfer case. OR, if someone monkeyed with something near your front axle, the cable may have been compromised.


Could have been a glich on yours, C4Tom... sending the encoder motor through the gear may have allowed it to 'find' its position. When an encoder motor goes bad, it won't tell the computer what position it is in and because the computer doesn't know, it will just move it to either extreme - 2Hi or 4LO. I would be curious to know if you do have 4Hi...

[Chazz44]

my blazer had a problem with the 4x4, and under the battery there is a vacuum. you said you don't think this is it, but it might be. My vacuum filled up with fluid and it rotted the rubber boot. I went to a chevy dealer and it was 103$$ brand new, but i got it from a junk yard for 15$$. Hope it works.

[Blazer69]

damn guess i need to pull my battery out then

[C4Tom]

Okay, I played with it again yesterday and it never lit the 4HI light. I can here it making a noise in the cab pushing each button. I can hear and feel it going tinto 4LO, I can hear/feel it coming back out of 4LO, but I can't tell you if it ever goes into 4HI. Is there a way for me to check this?

[Tink]

If you don't have 4HI, but you do have 4LO, that usually indicates encoder motor failure... the computer doesn't know exactly what position the case is in, so it just moves to either extreme - 2HI or 4LO.

I wrote/put together a post on common push button 4wd problems, diagnostic trouble codes and repair... check it out:
http://www.s10planet.com/forum/showthread.php?t=9749

[TreasonAgainstCaesar]

put it on a hoist and see if the front wheels spin when you put in drive. Or pull up to a curb/bumper block. and try and roll over it. It's much easier in 4wd than 2wd. But honestly, if the light is not on, I'm going to say it's not staying in 4wd.

[C4Tom]

Yea Tink... I printed out your whole article. It was awesome, great information and what prompted me to investigate. Thank you for taking the time to write that up!

Good idea, I will put it on jackstands and test it out. But I think Tink is right, I'm probably looking at getting a new encoder.

[Tink]

Thanks, with more 4wds here, thought it might be useful - plus I needed the info since now I have 2 push button 4wd blazers.

[TreasonAgainstCaesar]

Good idea, I will put it on jackstands and test it out. But I think Tink is right, I'm probably looking at getting a new encoder.

Ok, you do have 4 jackstands, right? I see a problem if you tried to only put the front end on the stands...

[C4Tom]

LOL Yup... it would be a bit hard to do, wouldn't it.

I have 4 jackstands and a 4x4 floor jack! I love that thing... it has an 24" lift and it's truly heavy duty! I use to put my Malibu drag car up on the stands to watch the drive train in action and store it that way in winter so the slicks didn't get flat spots. I believe that safety equipment should never be purchased at a discount house.

[Slacker1357]

"I paid 2.99 for something just like that. It must have cost ya $20"
"yeah"
*SNAP*"OH SH*T!!!!"
"how you doin pinned under your car?"

[TreasonAgainstCaesar]

LOL Yup... it would be a bit hard to do, wouldn't it.

I have 4 jackstands and a 4x4 floor jack!

Ok, just wanted to double check that for you. You normally seem pretty sharp, but there was that one time when you checked your 4LO without checking your 4HI. ;)

[C4Tom]

:lol: Okay.... you got me. Old age sometimes kicks in and does that to you... just wait and see. LOL :D

[Slacker1357]

Im digging my old thread back up...
mostly for the title...

My new problem is Im stuck in 4Hi. I try to press the button, and no reaction.
at first I had a code telling me low power input. I knew that was corrosion, and I spliced in a non corroded wire harness, wire by wire. (Its done right too)

I dont know what the deal is now. Does anyone have that diagram of the pins to connect? I think I have it right, I just wanna make sure.
I might wind up buying a new TCCM

[Slacker1357]

bump?

[TreasonAgainstCaesar]

Is it the same code after you swapped the plugs?

[Slacker1357]

I've actually yet to check the code again for the 4wd issue. The last thing that was popping up was the cyl 4 misfire...

Im actually looking at replacing the push button, and then the TCCM. Hope something works... but I need to get the parts.

[TreasonAgainstCaesar]

At least find out if the lower power code is still there. Have you tried shifting to 4low?