90 Checy 4x4 not working - The 1947 - Present Chevrolet & GMC Truck Message Board Network

86 Rado · 02-21-2011, 09:00 AM

I am new to this whole 4x4 thing and mine is not working. I shift it into 4 wheel drive. but get nothing. What are the most common things I should look at first? I put the truck in neutral and engage 4 wheel drive, sometimes it will grind a little but not allways as I shift it in. It has the floor shifter to engage it. Thank for your assistance.

jrdv · 02-21-2011, 10:45 AM

If I remember correctly, there is an electric actuator that is in the front diff. Check for loose connection or wiring. It will be on the right side of the diff and the wires go to the transfer case.
I know that it has the manual shifter, but it is still electronic.
The solenoid?? in the diff is know to go bad.

Hope this helps a little.

John

86 Rado · 02-21-2011, 11:43 AM

I have learned alot about this in the last hour. Are you talking about replacing the actuator? I can get that at autozone for $87 but I guess I need to check the fuse first.

propanemudtruck · 02-21-2011, 12:57 PM

I ran into this with the plow truck a few weeks ago, well the harness got torn out of the truck while I was plowing...

I made a slug that is the length of the actuator when engaged and slid that in then screwed the acutator back into the diff. Works like a charm! Not really the proper fix, but it's a plow truck!

86 Rado · 02-21-2011, 03:42 PM

I did go out and check the fuse, lookes good. I put it down in 4L and drove it just a minute. It was definately on low and drover a little different. I could hear the fron end whining somewhat. But lights never lit up. W 2 weeks ago I tried to use it and the front wheels just sat there while the backs were spinning. Does this help any to narrow it down. Been raining all day, so I cant get under it till this crap stops.

BLACK AND BLUE 67-72 · 02-21-2011, 07:15 PM

More than likely your actuator in the front differental is out. Your truck will drive different when it is in low, because of your transfer case. Crawl under it and look at the front end and make sure the wires are hooked up still.

propanemudtruck · 02-21-2011, 07:39 PM

to test that actuator when it dries up, simply remove it and hook it to a 12 volt power source. If it extends just under an inch at the end, it's working. There are 4 wires, two to confirm it's in 4 wheel and the two that activate the actuator.

86 Rado · 02-21-2011, 07:46 PM

Is this easy to get to or do I have to remove anything to get to it? I dont have any kind of power source unless I can use my battery charger. Sorry if I sound stupid, just not an electrical or much of a real mechanic for that matter.

onebadbowtie · 02-21-2011, 09:54 PM

Quote:

Originally Posted by 86 Rado

Is this easy to get to or do I have to remove anything to get to it? I dont have any kind of power source unless I can use my battery charger. Sorry if I sound stupid, just not an electrical or much of a real mechanic for that matter.

just take some wire a hook them to positive and ground posts on your battery in your truck and to the actuator

propanemudtruck · 02-22-2011, 07:53 AM

It takes a fairly large crescent wrench or channel locks to get around the actuator, but there's room from underneath to spin it out. have fun getting dirty!

86 Rado · 02-22-2011, 08:35 AM

Thanks for all your help. I will give it a shot. "Have fun getting dirty" come from a mudder, sound like you do. One other thing, does it hurt to drive it while its out or must I reinstall it.
Thanks
Jerry

propanemudtruck · 02-22-2011, 10:02 PM

Wouldn't be the best idea, I great 1" hole for fluid to get out and debris to get in...

It's been a while since I really had a mud truck, but I find ways to get dirty... The weapon of choice was an S10 blazer with 1 ton running gear, 40" tires and an LP powered 366 BBC. Those were the days!

rayfinseats · 02-22-2011, 10:13 PM

Re: 90 Checy 4x4 not working

--------------------------------------------------------------------------------

If I remember correctly, there is an electric actuator that is in the front diff. Check for loose connection or wiring. It will be on the right side of the diff and the wires go to the transfer case.
I know that it has the manual shifter, but it is still electronic.
The solenoid?? in the diff is know to go bad.

I agree: MINE WENT BAD ON MY 90 1500 once. Same issue. Easy to change.

Hoods69BadBowTie · 02-23-2011, 12:18 AM

Yep there is the actuator in the front diff that can go bad. There is also a cheaper part on the transfer case that can go bad. Its a little sensor/ actuator that is magnetic I believe and it sits on the top of the transfer case. Has a 2 prong that goes into. This was bad on my '88 and the diff actuator was still good. I think I got the part at oreilys and it was like 10$ or 15$. Hope this helps.

86 Rado · 02-24-2011, 02:20 PM

Ok, I was able to check the actuator and it goes out when engaged and back in when not. Seems to function as it should. What should I go to next. Someone said part of differential? Thanks for everyones input.

jrdv · 02-24-2011, 11:03 PM

Only thing to do now is swap in a solid front end!

86 Rado · 02-24-2011, 11:26 PM

What about that indicator switch?

Hoods69BadBowTie · 02-25-2011, 12:03 AM

Did you try the one that goes on top of the transfercase like I was talking about in my other post. Here's a link to a pic of it from google http://www.monsterautoparts.com/CHEV...4%20switch.jpg

02-21-2011, 09:00 AM	#1
86 Rado Registered User Join Date: Feb 2010 Location: Anderson, Indiana Posts: 33	90 Checy 4x4 not working I am new to this whole 4x4 thing and mine is not working. I shift it into 4 wheel drive. but get nothing. What are the most common things I should look at first? I put the truck in neutral and engage 4 wheel drive, sometimes it will grind a little but not allways as I shift it in. It has the floor shifter to engage it. Thank for your assistance. __________________ 09 Black Challenger R/T 90 Scottsdale shortbed 4x4 71 Impala Custom

02-21-2011, 10:45 AM	#2
jrdv Registered User Join Date: Apr 2000 Location: new mexico Posts: 948	Re: 90 Checy 4x4 not working If I remember correctly, there is an electric actuator that is in the front diff. Check for loose connection or wiring. It will be on the right side of the diff and the wires go to the transfer case. I know that it has the manual shifter, but it is still electronic. The solenoid?? in the diff is know to go bad. Hope this helps a little. John __________________ 1972 3/4T 4x4 Chevrolet (383) 1971 c-10 SWB (400 sb) 1972 4x4 Blazer 1969 SWB 4x4 GMC Projects: 1972 stepside 4x4 http://67-72chevytrucks.com/vboard/s...d.php?t=280132 http://67-72chevytrucks.com/vboard/s...d.php?t=285952 http://67-72chevytrucks.com/vboard/s...d.php?t=553672 http://67-72chevytrucks.com/vboard/s...d.php?t=522704

02-21-2011, 11:43 AM	#3
86 Rado Registered User Join Date: Feb 2010 Location: Anderson, Indiana Posts: 33	Re: 90 Checy 4x4 not working I have learned alot about this in the last hour. Are you talking about replacing the actuator? I can get that at autozone for $87 but I guess I need to check the fuse first. __________________ 09 Black Challenger R/T 90 Scottsdale shortbed 4x4 71 Impala Custom

02-21-2011, 12:57 PM	#4
propanemudtruck Local Redneck Authority Join Date: Mar 2009 Location: Grand Rapids, MI Posts: 584	Re: 90 Checy 4x4 not working I ran into this with the plow truck a few weeks ago, well the harness got torn out of the truck while I was plowing... I made a slug that is the length of the actuator when engaged and slid that in then screwed the acutator back into the diff. Works like a charm! Not really the proper fix, but it's a plow truck! __________________ -Kevin four on the floor feel the beat in your soul movin to the rhythym pumpin til ya cant take no more dance if you want to do what you came to you cant ignore the feeling of that four on the floor

02-21-2011, 03:42 PM	#5
86 Rado Registered User Join Date: Feb 2010 Location: Anderson, Indiana Posts: 33	Re: 90 Checy 4x4 not working I did go out and check the fuse, lookes good. I put it down in 4L and drove it just a minute. It was definately on low and drover a little different. I could hear the fron end whining somewhat. But lights never lit up. W 2 weeks ago I tried to use it and the front wheels just sat there while the backs were spinning. Does this help any to narrow it down. Been raining all day, so I cant get under it till this crap stops. __________________ 09 Black Challenger R/T 90 Scottsdale shortbed 4x4 71 Impala Custom

02-21-2011, 07:15 PM	#6
BLACK AND BLUE 67-72 Firefighter Join Date: Feb 2001 Location: Yellville, Ar, USA Posts: 1,943	Re: 90 Checy 4x4 not working More than likely your actuator in the front differental is out. Your truck will drive different when it is in low, because of your transfer case. Crawl under it and look at the front end and make sure the wires are hooked up still. __________________ '72 Chevy SWB 350 Auto '67 GMC LWB 350 4 speed '70 Chevy 4x4 Stepside 350 Auto Yellville, Ar. USA

02-21-2011, 07:39 PM	#7
propanemudtruck Local Redneck Authority Join Date: Mar 2009 Location: Grand Rapids, MI Posts: 584	Re: 90 Checy 4x4 not working to test that actuator when it dries up, simply remove it and hook it to a 12 volt power source. If it extends just under an inch at the end, it's working. There are 4 wires, two to confirm it's in 4 wheel and the two that activate the actuator. __________________ -Kevin four on the floor feel the beat in your soul movin to the rhythym pumpin til ya cant take no more dance if you want to do what you came to you cant ignore the feeling of that four on the floor

02-21-2011, 07:46 PM	#8
86 Rado Registered User Join Date: Feb 2010 Location: Anderson, Indiana Posts: 33	Re: 90 Checy 4x4 not working Is this easy to get to or do I have to remove anything to get to it? I dont have any kind of power source unless I can use my battery charger. Sorry if I sound stupid, just not an electrical or much of a real mechanic for that matter. __________________ 09 Black Challenger R/T 90 Scottsdale shortbed 4x4 71 Impala Custom Last edited by 86 Rado; 02-21-2011 at 07:47 PM.

02-22-2011, 07:53 AM	#10
propanemudtruck Local Redneck Authority Join Date: Mar 2009 Location: Grand Rapids, MI Posts: 584	Re: 90 Checy 4x4 not working It takes a fairly large crescent wrench or channel locks to get around the actuator, but there's room from underneath to spin it out. have fun getting dirty! __________________ -Kevin four on the floor feel the beat in your soul movin to the rhythym pumpin til ya cant take no more dance if you want to do what you came to you cant ignore the feeling of that four on the floor

02-22-2011, 08:35 AM	#11
86 Rado Registered User Join Date: Feb 2010 Location: Anderson, Indiana Posts: 33	Re: 90 Checy 4x4 not working Thanks for all your help. I will give it a shot. "Have fun getting dirty" come from a mudder, sound like you do. One other thing, does it hurt to drive it while its out or must I reinstall it. Thanks Jerry __________________ 09 Black Challenger R/T 90 Scottsdale shortbed 4x4 71 Impala Custom

02-22-2011, 10:02 PM	#12
propanemudtruck Local Redneck Authority Join Date: Mar 2009 Location: Grand Rapids, MI Posts: 584	Re: 90 Checy 4x4 not working Wouldn't be the best idea, I great 1" hole for fluid to get out and debris to get in... It's been a while since I really had a mud truck, but I find ways to get dirty... The weapon of choice was an S10 blazer with 1 ton running gear, 40" tires and an LP powered 366 BBC. Those were the days! __________________ -Kevin four on the floor feel the beat in your soul movin to the rhythym pumpin til ya cant take no more dance if you want to do what you came to you cant ignore the feeling of that four on the floor

02-22-2011, 10:13 PM	#13
rayfinseats Registered User Join Date: Dec 2010 Location: sioux city, iowa Posts: 619	Re: 90 Checy 4x4 not working Re: 90 Checy 4x4 not working -------------------------------------------------------------------------------- If I remember correctly, there is an electric actuator that is in the front diff. Check for loose connection or wiring. It will be on the right side of the diff and the wires go to the transfer case. I know that it has the manual shifter, but it is still electronic. The solenoid?? in the diff is know to go bad. I agree: MINE WENT BAD ON MY 90 1500 once. Same issue. Easy to change. Last edited by rayfinseats; 02-22-2011 at 10:14 PM.

02-23-2011, 12:18 AM	#14
Hoods69BadBowTie Chevys Kick A$$ Join Date: Jan 2005 Location: Zootown, MT Posts: 12,699	Re: 90 Checy 4x4 not working Yep there is the actuator in the front diff that can go bad. There is also a cheaper part on the transfer case that can go bad. Its a little sensor/ actuator that is magnetic I believe and it sits on the top of the transfer case. Has a 2 prong that goes into. This was bad on my '88 and the diff actuator was still good. I think I got the part at oreilys and it was like 10$ or 15$. Hope this helps. __________________ HOODS is what I answer too -'79, '77, '88 Pickup Sold, '85 Camaro, '83 T/A, '81,'83,'90 K5 Blazer All Sold -'79 3/4 ton "Big Yellow Bananna" Lifted 4spd. 39.5 TSL Swampers, The money Pit -'86 K5 Blazer Silverado 6.2 4" lift 35"s -'95 Ext. Cab Shorty 4" Tuff Country rolling 35" M/T's -'83 Monte Carlo T-Tops. 126,500 Original Miles -LATER I would rather push a Chevy then drive a ford!!

02-24-2011, 02:20 PM	#15
86 Rado Registered User Join Date: Feb 2010 Location: Anderson, Indiana Posts: 33	Re: 90 Checy 4x4 not working Ok, I was able to check the actuator and it goes out when engaged and back in when not. Seems to function as it should. What should I go to next. Someone said part of differential? Thanks for everyones input. __________________ 09 Black Challenger R/T 90 Scottsdale shortbed 4x4 71 Impala Custom

02-24-2011, 11:03 PM	#16
jrdv Registered User Join Date: Apr 2000 Location: new mexico Posts: 948	Re: 90 Checy 4x4 not working Only thing to do now is swap in a solid front end! __________________ 1972 3/4T 4x4 Chevrolet (383) 1971 c-10 SWB (400 sb) 1972 4x4 Blazer 1969 SWB 4x4 GMC Projects: 1972 stepside 4x4 http://67-72chevytrucks.com/vboard/s...d.php?t=280132 http://67-72chevytrucks.com/vboard/s...d.php?t=285952 http://67-72chevytrucks.com/vboard/s...d.php?t=553672 http://67-72chevytrucks.com/vboard/s...d.php?t=522704



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02-24-2011, 11:26 PM	#17
86 Rado Registered User Join Date: Feb 2010 Location: Anderson, Indiana Posts: 33	Re: 90 Checy 4x4 not working What about that indicator switch? __________________ 09 Black Challenger R/T 90 Scottsdale shortbed 4x4 71 Impala Custom

02-25-2011, 12:03 AM	#18
Hoods69BadBowTie Chevys Kick A$$ Join Date: Jan 2005 Location: Zootown, MT Posts: 12,699	Re: 90 Checy 4x4 not working Did you try the one that goes on top of the transfercase like I was talking about in my other post. Here's a link to a pic of it from google http://www.monsterautoparts.com/CHEV...4%20switch.jpg __________________ HOODS is what I answer too -'79, '77, '88 Pickup Sold, '85 Camaro, '83 T/A, '81,'83,'90 K5 Blazer All Sold -'79 3/4 ton "Big Yellow Bananna" Lifted 4spd. 39.5 TSL Swampers, The money Pit -'86 K5 Blazer Silverado 6.2 4" lift 35"s -'95 Ext. Cab Shorty 4" Tuff Country rolling 35" M/T's -'83 Monte Carlo T-Tops. 126,500 Original Miles -LATER I would rather push a Chevy then drive a ford!!

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