U da man. I have 2001 blazer trailblazer package. Been replacing 4wd diff motor and actuator. 4wd was still stuck on. Vehicle was sitting for years prior. Thanks for the detailed video. 4wd now working
Won't fully disengage. Collar gear was rubbing on the smaller gear. Actuator is good, changing the cable and will also be checking the ball valve now. Thanks for the video man I hope this fixes it. I don't feel like ripping that damn diff out again.
Thank you. I found the problem. it's not the switch. Want found was the 4x4 control module plug lost connection so want I did was pull the plug out of the module. and plugged it back in now my 4x4 switch is working now.
Had the truck bang bang bang at low speed ( Like coming out of a parking spot while turning the wheel ) it felt like it was hopping over and the 4wd would flash 2HI to 4Hi back to 2Hi Had a feeling it was the Front diff as everything else was Ok ..just started a full front end replacement as it lasted since 05 and took the diff out and checked the gears ..Yup the smaller ring gear was worn hard on the edges ..Cause is the actuator valve switch ..Changing out the seals as well
Anywhere to find a vacuum diagram for an 98-04 model. I replaced vacuum lines with new. Used fuel line, now I’m not getting any vacuum up front at the diaphragm. Everything was seal tight just wondering if I have hoses switched at t case?
Chevy has guide lines for usage of ur four wheel drive system for the blazer s10 truck ur supposed to ingage ur four wheel drive system at least once a month to keep it in good working order.
like the fact u took time to help others try to fix there problematic blazers .but there's a lot more to it then just the t case.its also do to owner's that don't service there vehicle's.
Awesome thanks and today I was trying to fix the darn dash I can't get past my ac and heat controls to get the dash out. Also it engaged into 4 high all day today no problem but I had to be in park and not neutral.. I have to be in neutral for low to engage
if your still having trouble getting the heat controls to come out, I have a video on here that may help. I take apart the dash to repair the cluster. its called digital dash repair s10 blazer
I replaced this part as well as the actuator which was destroyed when transmission fluid leaked through the vacuum line. The new switch did not prevent the TF from leaking and it destroyed a 3rd and fourth actuator until I solved the problem by installing a check valve that allows vacuum but not fluid from the transmission. In order to revert to 2wd, I have to manually release the vacuum. I do this by having a dual ported check valve. I have a vacuum line extending out with a plug in it. I remove the plug for a second to release the vacuum after pushing the 2wd button.
When I first bought my 97 s10 I had same scenario with tf in the vacuum actuator under battery tray, which I'm assuming you're talking about . Ended up having to replace transmission due to 3rd and 4th clutch packs burnt and while I was at it, I changed the seal in-between the trans and t-case. This is what led the tf to get into the vacuum actuator. It was flowing past the trans/t-case seal, through the actuator in this video, then up the vacuum line to the vacuum actuator under battery tray. May or may not be the same prob as yours. If you ever decide or need to take trans out, you might want to consider this if you want standard working four-wheel drive again, that is if you haven't already known. I'm going to keep your set up in mind as well for future reference. Thanks for that idea.
i had issues too i had a blown out actuater ,this switch is next on my list ,weather it works or not im getting it,your right dont need that shit i have 03 chevy s10 4x4 zr2 good vid yea and its a bitch to get to stubby 7/8 wrench is best
So im losing my mind trying to figure out why my 4x4 aint working. Started going threw everything. Found my vac line going from my intake to other vac lines was worn and had holes in it. Replaced one simple line bam got to get my truck muddy lol
I need to know where vacuum lines on 93 S-10 4wd go.Which one does the vacuum line from manifold connect too.And which one goes to vacuum pod under battery.All vacuum lines are unhooked from 4wd vacuum pod
Chevy made these way too complicated to EVER work when you really need it. A dedicated microcomputer just for 4WD, 3 lighted pushbuttons (2H,4H,4L), a gear reduced motor + complex encoder switch that reports the exact position to the computer (If the switch gets dirty, it'll lock you out of 4H), over 12 feet of vacuum lines (routed too close to the exhaust so it's SURE to crack and fail), a vacuum switch pictured here, and a vacuum motor complete with a cable that dies from corrosion since they put it under the battery box. I've had it all fail by now on my '96... Right now I need the cable where the sheath got a nick in it and rotted through from battery acid. I had it all working in preparation for winter, replaced all vacuum lines, etc. - 1st snow, and no 4wd AGAIN! Someday I'll put a manual front axle cable on it so I can engage it from the dash, and cut a hole in the floor and install a manual shifter to take the place of the motor and computer! The sickening part is that you can put these in 4wd with a pair of vise grips from under the vehicle with all that crap (encoder motor) removed! No computer needed. What the heck were they thinking!!??
It's complicated but 'push button' so that a witless twit can operate it. Back in the day of locking front hubs and manual transfer cases, you had to actually understand what you are doing and be able to do it. Now any moron can go 4 wheel'n, and they do, until a vacuum line falls off or melts through. This system is designed so lame and lazy minded people can drive in snow and icy conditions to fast and crash.
This worked on my old one thanks for the video, it was working but going by a jersey barrier I’d here that clicking.. but I bought another s10 blazer and 4lo goes in and out but, 4hi when in neutral press it and 4hi light and 4lo light both blink 5 times and nothing happens. And in park or driving I press 4hi and nothing happens.
Mine does the same . 4w low goes in .. 4w high won't engage, goes to 2w high... 4w lows engages... vacuum leak? Bad dash 3 button switch? Any ideas? HELP !!!
Great video - thanks , helped a lot with my Sonoma which wouldn't engage front axle! Now: please give us LINK to your video about installing MANUAL CABLE TO LOCK this so we can toss the idiotic actuator mess.! I tried all RU-vid sites for bam6972, nothing.
Could that switch sticking affect the cruise control? My front doesn't engage unless I stop, shift to 'N' and push 4-Lo on my 3-button 98 LT. I've noticed my cruise control sometimes works-sometimes doesn't.
i have a 1998 blazer the push buttons light up and it feels like the four wheel drive in-gauges but the it doesn't still don't pull.. i need some options on what to do is there a valcum line that t's off to the side on motor also? ,
under the battery is a vacuum actuator that locks the front differential in. take your battery out and take the vacuum line off the actuator then put battery back in. start it up put it in 4x4 hi then check to see if you have vacuum from that line. if not then check that line all the way back to the transfercase and all the other vacuum lines. if you do have good vacuum at the actuator then check and see if the actuator holds vacuum and not torn/ripped. if that checks out good to then check and see if you can manually move the cable that's hooked to the actuator by hand. if not then replace.
my 1994 sanoma will go into 4 wheel drive but when I give it the gas it comes out of 4 wheel drive,could this be my problem I've replaced actuator under battery and the transfer case motor
you should have a vacuum ball that a vacuum line ts into. it stores vacuum for when the throttle plate is open like when you give it gas it looses vacuum. thats the purpose of a vacuum canister/ ball. if you have a line that is dry rotted to the point that its collapsed or there is a hole in it then it wont have enough vacuum to keep the actuator pulled. check all vacuum lines and the vacuum canister. there is also a one way valve that helps keep the vacuum stored at the canister. it should be located near the intake. you should be able to blow one way but not the other through it.
My 04 blazer is driving me crazy cant figure it out. Sounds like my transfer case is engaging, actuator under battery is pulling lock in my 4wd front dont pull. Replaced cable still nothing. My mechanic changed my oil lines so I had him check out my 4wd. Hes always really swamped up with work so its hard to chit chat with him but he said he had it on the lift and it seemed like my cable wasnt pulling enough so he adjusted it and said he got it working on the lift. I got it home locked it in thought it was working almost got stuck in a mudhole because my front tires still aint pulling.
the oil lines have noting to to wit the 4x4.... it sounds like a collare gear problem... check for vacuum at the actuatore under battery tray in 4x4.. if none then check and see if actuatore motor is working . lights in on dash means its working.... most of time....clicking 4x4 repair blazer jimmy sonoma s10 trailblazer front axle watch my vid and I hope I can help you
I have a problem with my 1999 Chevy S10 4 wheel drive that i would love to have some suggestions.. I have a new vacuum actuator under the battery and can not get the front axles to pull.. i Removed the cable and manually engaged the differential (i hope) as to the cable was a bit tight.. The front still did not pull.. No weird noises of any sort and the 2wd, 4H, and 4 low swapped the way it should have, just no front end engagement.. I have not replaced the vacuum valve you spoke of, hoping manually pulling the cable would satisfy the problem and a direction to look in.. Please Help!! Thank You..
you cant just pull the cable, hop in and expect it to be engaged. once you start moving the gear will slip out of place. disconnect the vacuum line from the actuator and lay it on top somewhere. then start the engine, put it in 4hi then see if your getting good vacuum from that line. if not then you have a vacuum leak somewhere.
replace all vacuum hoses and this switch. also pop the fill plug out of the transfer case to make sure it is not overfilling due to a bad input seal. this might be the cause of the lines having oil in them.
i have a 1999 blazer the push buttons light up and it feels like the four wheel drive in-gauges but it doesn't and will not go in to 4x4. I have vacuum to the front actuator. Help!
does the light stay on in the 4hi button when you push it? or does the light go off? if it just goes off. then its more than likely the encoder motor on the t case. also if you have vacuum to the front actuator that means the encoder motor actually is doing its job. then I would assume the cable from the actuator to the front diff is seized up. take the cable off the actuator and pull on it. it should move maby half an inch then go back in. maybe a quarter inch. it doesn't move much. also check the actuator under the battery for holes. push the diaphragm all the way in and put your finger on where the hose goes into it. if it springs back up within 10 seconds or so then its got holes in it and is not strong enough to pull the cable. does it click when in 4x4? if so the color gear in the front diff has chewed up teeth. easy fix .. kinda. if all this checks out then I would check the vacuum to the actuator. put a vac meter on that line. start the truck engage 4x4. it should read 15-20 psi or vacuum in pounds or whatever. if not then I would check all the vacuum lines for dry rot or soggy by trans oil. another story. input seal on tcase could be leaking causing trans fluid to overfill the t case and get sucked up through the vac lines cause of a bad vac switch in this video. hope this helped.
I have a 93 s15 jimmy and I can on very rare occasions get my 4 wheel high to engage. I have no problems getting into 4 wheel low and sometimes if I click 4 low it will engage into 4 high. What happens most of the time is it will click and my 4 wheel lights will flash and then it will reject 4 high and go back to 2 wheel or it will go into low when I try to engage 4 high. I would appreciate any suggestions on how to fix this. Thank you
that is 90% due to the encoder motor on the transfer case. there is a sensor in the encoder motor that goes bad over time. replace the encoder motor and all will be fine after that. guarantee it.....
if this switch has been bad for awhile then it could have sucked transmission fluid into the vacuum lines because of a transfer case input seal being bad and overfilling the t case from the transmission. take some vacuum lines apart from under the hood and see if they are oil soaked. there is also a small plastic like vacuum line that goes into the firewall on the driver side. make sure that line isnt broke or became disconnected. that small line is the vacuum feed for the blend doors in the dash.
+Gary Rock - No... I just did those HEAT / AC Settings Actuators. They are separate and if you take the Dash off, you can see it under there. Play with those, pull in and out, you will see how they work. Once you understand it, you will need to replace them individual.
yes. you should stll have a vacuum actuator under the battery or on the fender well. maby I think. check for vacuum at the actuator when running and in 4x4. if none then check all vacuum lines. if its all manual then check the shift cable from the lever to the front axle. it might be broke.
Okay so I have a 03 blazer when I push either 4hi or 4low I can hear the transfer case lock in nd my lights go solid so i know my tcase is locked in and I'm manually locking my front end in by pulling the cable, I've plugged the airline but still no 4x4 can anyone help?? Thanks
ok so jack up the front end so both wheel are off the ground. pull the cable and lock it in place. then spin one tire. the other tire will start to spin. if it doesnt spin something is wrong in the diff. if it does spin the other tire then something is not locking up in the t case.
the switch in my truck doesn look like that why? its a blazer,i changed the cable, too,but not the switch,do you think the problem is inside the axle??
I found the problem. The 4x4 control module located on the passenger side door panels under the clover box. It lost connection in the the plug so want I did is pulled the plug out of the control module in an out two time. And then plugged it back in now my for wheel drive switch is working fine. I hope this will every one who has this problem with there s10 blazer or s10 pickup 4x4.
I have a 2000 Chevy blazer that I had stuck in 4 low I put it into nutual and hit 4 high and 2 high wouldn't come out wouldn't click wouldn't do a thing like I had power to nothing not even the transfer case motor I took the front drive shaft out and the transfer case motor off put power to it it works I put in a new transfer case control module that didn't fix it but I have power to nothing I know the switch in the truck works but do u think this may be my problem or something else??
when you hit the 4hi button does it light up? if not then check fuses. the fuse your looking for will either be labeled 4wd or tccm. if fuse is ok then I would replace 4wd switch.
I don't even have a light on in the switch its self any more but maybe a few seconds in all 3 when I fire the truck up then all off them go out but ill look over the fuses and see what's up one other thing because this is electrical BS... dose the transfer case motor have to be on the transfer case pluged up because it needs a ground to work possibly but thanks ill be sure to let you know what happens!
yes I would put the motor back in BUT because you moved it out of the vehicle it might not be in the right position when you go to install it. so now its difficult. because the motor might be in a different position then the transfercase. so it screws things up a bit when you go to install it again. just have to watch out for that. also the buttons have tiny bulbs in them that burn out over time. check for that too.
Hello, I have an issue. I drive a 1997 Chevy Blazer 4WD. About a month or two ago i discovered this loud humming whenever I accelerate to 60+mph (2WD). The sound seems to originate to the front, right tire. When I slow down, the noise get lower pitched, until I get around 10mph;then I hear a "POP" and my vehicle is back to normal. There has also been times where I have been running errands and the vehicle will start making that noise even at low speeds around 15mph (driving through the parking lot). I simply bring the car at 5-10mph, hear a "CLUNK" and the vehicle is back to its usual self. I'm not sure what this is! I feel like its something with my 4WD kicking on? Maybe a joint is getting lose or something? Any ideas?
if it was a ujoint u would have play in the front or rear drive shaft. check for play. also if it was the switch, take it out and check and see if the ball is stuck in the pushed in position. if it is, then replace it.
im having a problem with a 2000 gmc sonoma 4x4 , when i push the switch to put in 4x4 it just clicks under the truck..do you have any sugestions..thanks..
then you have a encoder motor failure. also on these newer models sometimes the 4x4 computer "tccm" will have bad corroded connections. this is located behind the passenger side kickpanel. to the right of your right leg. try cleaning the connections at the plug. if that don't work. pull the 4x4 or tccm fuse out for 10 minutes. then put it back in and try it. if it works then the encoder motor has failed.
+dshedder1 it could be that the actuator has a hole in it or one of the vacuum lines have a hole in them. also if you or somebody else ever removed the vacuum ball then that would cause it to disengage when u speed up with throttle. since the ball stores vacuum when the throttle is opened.
+billytomrame2 9 out of 10 times its the encoder motor on the transfer case. replace that and it should work again. its because of the sensor inside gets worn out and cant determine if its in 4 hi so it goes back to 2hi. 2 hi is in the middle and 4 hi is the last notch. that's why it goes into 4lo and not 4 hi . its easier to tell if its in 4 lo then it is 4 hi. because 4 hi is in the middle.
This happened to me. I changed the switch and now the actuator let go of the cable. Now my front axles dont engage at all. Can I bring it to you to fix it? Does this mean I need a new Transfer case?
2WD / 4 WD BOTH have Vacuum and they work hand and hand.... Check BOTH Vacuum / Switch !!! Just because the Back works, that doesn't mean the Front does and vise versa!
my sons 98 gmc jimmy will go into 4x4 but then will go right back out. now hes saying it wont go in at all you think this could posibably be the problem?
it could be the encoder motor on the side of the transfer case. if the light blinks then goes back to 2 wheel drive then the motor is likely the problem.
ok thats what it is doing and the what im assuming is a solenoid in the passenger side kick panel and it just clicks on and off and then it goes back in the 4low so I'm going to get her there and tap it with a hammer because it didn't start doing it until it got really cold outside and see if I can't get it to lock in at least four high and then work on getting that change later
I have a 99 GMC Sonoma four wheel drive 4.3 L engine I bought $800. I've always had an issue with the four wheel drive not working. I played around with it before I also replace the actuator under the battery still nothing. I've actually jack up the front end on a truck at the junkyard and manually engage it using the cable under the battery and when I turn the wheels both wheels for turn the same direction. Now when I do it to my truck the same way put on the cable going down to the front differential from under the battery I get no response. The weird thing is I had a vacuum leak but I discovered a while back and I've replaced it with a new vacuum line that whole section and ended up going down the road one day about 50 miles an hour and started hearing some clicking noises I slow down it was stop. So I unhooked the actuator under the battery and clicking noise went away. Now I discovered watching other videos on RU-vid that this was caused by it's partially engaging. Any ideas on what could be causing it? Like I said I did that trick pulling on the cable or with the jacked up in the air at the junkyard and it worked perfectly both Wheels turn the same direction but mine doesn't have the same result. It seemed to me that there's a problem with either the cable or maybe it's internal inside the differential. Hopefully someone can shed some light on what I could do.
Ok I pulled the transfer case fill plug and it is completely full of transmission fluid so I would say it's seal between transmission and transfer case ....any thoughts
replace seal and switch/ vacuum lines and it will stop transmission fluid from entering the vac lines. if you let it drain from the fill plug then watch your transmission fluid closely. over time it will overfill it again and transmission will be low and if left untreated will burn up the transmission.
there's a another switch on the 90,91,92,93,94, for the front differential that is also problematic it's called the switch indacater that's what I got plus the t case switch , actuawaiter and cable.the switch indacater fits in the front differential.
yea the switch on the front diff is also a ball type that likes to stick after awhile. some pb blaster and some time will free it up for as long as the truck lasts.
Thanks.i went ahead and bought that two the local Chevy dealer is charging $198 for the installation of the cable.and I'll have a warranty For repair GM still makes parts for the blazers if u want to buye them.
oh ok you cant get the boot at a part store. you will have to go to a junk yard and get another one and look up a vacuum hose diagram to make sure you put the hoses on the right spots or the 4x4 wont engage. the vacuum hoses a part store will have in stock
Hey I encountered this issue and drove it for about 45 minutes on the highway. I didnt know what the issue was at the time. I installed a new switch and it stoped grinding in 2hi. The truck shifts into 4x4. How would I know if the gear is stripped? Thanks.
If I goes on 4x4 still then I would replace all the vacuum lines going to and from the transfer case. And replace the vacuum switch on the t case. Just make sure you know which line goes where on the switch. It has 3 lines. A vacuum source and then it goes to the actuator under the battery tray. The the 3rd is just a vent.
@@bam6972 thanks for the reply. I did replace all the vacuum lines to the case and the switch. I took the truck on the beach over the weekend and the 4x4 worked well over the sand. However, I'm not sure if the front axle locks since that gear was grinding. Would it have gotten stuck in the sand if the gear was badly stripped out? I heard I can jack the right wheel up and put it in 4hi in park and try to spin the right wheel to see if it's locked.
its on top of the transfer case driver side. theres 3 vac lines going to it. its really hard to see. your head pretty much has to touch the front drive shaft lol. its in a tight spot. but I was able to break it loose with a 7/8 wrench and use my fingers to bring it the rest of the way out.
Hey man my wife has a 98 Jimmy & has no problem going in to 4 wheel ' but as U drive it ' even after U switch back to 2 wheel It takes a min. or so then makes a thud noise when it finely disingages ' FUCK ! Could this be the problem ? jimmiesteve47
my 1990 has a stick shift & it won't budge it's stuck on 2 wheel thank god i thought it was the actuator but it's not so from the looks of it your saying that it's that screw &your also saying that it's a bitch to remove also????
+nick diaz its not that bad to change out. but is yours just not going into 4x4? if so then check vacuum lines and the actuator under the battery tray for tears. 80% of the problem.
OK THANKS A BUNCH I WILL I,,, WASN'T SURE WHERE THE VACUUM WAS ,AS FOR MY SHIFT IT'S STUCK IT WON'T MOVE I DON'T WANT TO FORCE IT SCARED TO BREAK SHIFTER WON'T GO FORWARD OR BACKWARDS. STUCK IN LIMBO LOL
oh ok so yours is manual 4x4. with the lever for 4hi and 4lo. you need to check the linkages under the truck for binding or it may have just rusted solid. spay some pb blaster on the linkages and see what happens.
OK THANKS GONNA GIVE IT A TRY BUT IS THE VACUUM UNDER THE BATTERY PLATE? I WOULD LIKE TO CHECK THAT TOO I HAVE NEVER CHANGED ANYTHING THAT HAS TO DO WITH THE 4WD SINCE I HAD IT .SO IT WOULD BE A GOOD IDEA TO CHECK A FEW OTHER THINGS I CHECKED THE ACTUATOR IT WAS GOOD , PROCESS OF ELIMINATION . THANKS !!
Fuck. So just took the battery out and see that the actuator is stuck fully on (I previously thought the problem was that it was stuck off). 4x4 was spotty and now I have none so have I just destroyed my front diff?
Actually the switch is not designed right because when the 4wd is disengaged in the transfer case there is a lever which stops pushing that button in BUT DOESN'T PULL IT BACK OUT! Lol. Why can't GM engineers understand this. It was designed that way so that this switch would be replaceable but it was bad design. I disconnected the vacuum hose that goes to my vacuum actuator, but still the cable is not being pulled enough back into the front differential.
maby the spring is broken. tear apart the differential and inspect the collar gears, spring.thats what I would do in this situation. when the 4x4 disengaged.... check for vacuum at the actuator hose. if there is vacuum then the switch is to blame.
So im losing my mind trying to figure out why my 4x4 aint working. Started going threw everything. Found my vac line going from my intake to other vac lines was worn and had holes in it. Replaced one simple line bam got to get my truck muddy lol
