Jump to content

1500 Hd 4wd System

TyeeMan

Recommended Posts

TyeeMan Enthusiast

TyeeMan

Posted
Posted

Hi Everybody,

 

I have 02 GMC 1500HD with the push button 4WD. What is driving my questions here is that I noticed on my garage floor that I have some gear oil drips that are coming from the left front corner of the truck, and there is a little gear oil sprayed up into the left wheel well. When I openned the hood it looked like the vent from the front differential was wet, like gear oil was dripping out of it. The area below the vent was wet too so I'm assuming that is where the gear oil is coming from. This has never happened to me before.

 

I thought I heard some time ago that there was a problem with gear oil being forced up the vent tube and out the vent, is this true? Any body know what the remedy is?

 

When I am in 2WD does the front drive shaft and the front ring and pinion still turn when the truck is moving? I would think that when the truck is parked I should be able to grab the front drive shaft and turn it (when in 2wd mode) I cant do that. Is that normal? I thought in 2WD the only thing spinning up front was the two drive axels and the front drive shaft was unlocked and not spinning.

 

How can I tell if the actuator on the differential is not deactivating or unlocking? Would I see a trouble code or light or something?

What exactly does the actuator on the front differential do? What does it actuate?

 

And as my topic description reads, , when I push the 4 Hi button what exactly happens? I mean I know the front end locks up and the drive shaft spins but I'm looking for details.

 

Sorry for all the questions but I know this is the forum to get the answers from, lots of good info here.

Thanks in advance for your help and please feel free to go into as much detail as you'd like.

hockeypro1411 Senior Enthusiast

hockeypro1411

Posted
Posted

In 2wd the front driveshaft won't spin. There's actuators in the transfer case that engage the front driveshaft when you press the 4wd button. There's no real way to tell if the front shaft disengaged when shifting back to 2wd besides having someone look at it while you roll forward. My favorite way to tell is to see if I can chirp or spin the back tires. Then I know for sure.

TyeeMan Enthusiast

TyeeMan

Posted
  • Author
Posted

So if the the front drive shaft does not spin when driving in 2WD (I kinda figured it didn't) then when the truck is parked in 2WD mode, why can I not turn the driveshaft by hand? To me it seems like the front end is engaged or locked in. Oddly enough my Sub is the same way.

 

What does the actuator on the front differential do? What does it engage or dissingage?

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • Mistycool
      2007 Silverado classic Cooling fan running

      By Mistycool · Posted

      I am having similar issues.. 08, 4.8L granted I did had a fender bender and minor damage up front passenger side but I don’t think it had anything to do with it.. I had the high and low pressure checked and my fan for my radiator keeps coming on.. replaced the pressure switch and don’t want to keep throwing parts at it. I did have some minor problems here and there like on long road trips sometimes the ac would get a little warm and then on the highway as soon as I give it a little gas or get a little heavier on the petal it started running cooler. Never had an issue with the ac besides the here and there.. but I also started having issues when I fuel up now it takes a bit to start ( super embarrassing) it runs fine and once started ( only happens after fueling up) starts fine any other time. Could they be related?
    • KARNUT
      Gas Prices

      By KARNUT · Posted

    • Atlas
      Gas Prices

      By Atlas · Posted

      Spent a small fortune on fuel this weekend.   $6.69 diesel, 18 gallons of that. $6.99 92-octane ethanol free, 10 gallons of that for yard machines $5.59 87-octane for one of the cars, 11 gallons.   $250+ and I didn't even get a tug.   Hormuz ain't Hormuzin again, did not see that coming...LOL
    • revmanii
      Auto start stop disable

      By revmanii · Posted

      Appreciate the advice. I've watched multiple videos. Most showing the most complex for those that have a center console, to one that showed maybe 2 pieces of trim being removed, like 6 screws, pulling back the screen and switch assembly, and installing the inline module. And this was a new/newer Silverado. That didn't look too bad. All the others show alot of trim pieces that need to be removed. I've broken those kind of tabs/clips on my C8 Corvette trying to get to the battery, and that was a lot less clips than what I think is involved here after watching multiple videos and looking at my dash today. I have one on the way. Called a reputable stereo place about installing it and got a "minimum" price of $175. Ouch! Looking forward to seeing what the instructions have to say.
    • Atlas
      Ac not keeping up

      By Atlas · Posted

      Hard to say what the issue might be. Anything from the ability to cool the AC condenser up front, to blend door issues in the HVAC unit, to refrigerant charge, to compressor issues or issues in the lines.   Report back what the techs find on the 29th.   GM has service publications which list acceptable vent temperatures and AC pressures at given ambient temps and humidity. They probably won't touch the system if it's operating within those ranges.   I'm also surprised to hear your 2024 with the L8T is still using R134a? I was pretty sure the HD's had switched to the new refrigerant around 2020.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...