Hi everyone, I am back at it with another 4wd post. If you take a look back at my other posts I recently (a few months now) got my 4wd “fixed” but I believe I am still having issues, albeit different issues.

first issue: when driving on the highway, in 2wd, after about 20 minutes or so my front end will start making a horrible whining noise, it sounds like passenger side but idk, and the only way to stop it is to switch the car into 4hi, as soon as it’s in 4hi the noise is gone even when switching back into 2wd. This doesn’t seem to effect driving or handling in any way but is extremely annoying and is something that sounds like it should be looked into.

second issue: I am not really sure if this is a issue or if I am just misunderstanding how a 4wd system works. So... from my understanding when 4lo is engaged you should only get stuck if you have two wheel spinning (front driver side and rear passenger side, for example) but if you only have one wheel spinning the diffs and the 4wd system should be still sending power to the other three wheels. So onto my issues, I recently tried driving through some deeper, heavy snow (roughly 6-8 inches, it is less than my cars clearance as the snow is not high centering or even touching the undercarriage) and with my car half in the snow and half on the snowy road (plowed, I have grip) my front wheel starts spinning and my car doesn’t want to go anywhere. I am very confused as when we recently had 24inches of snow at my house my blazer crawled through it without a issue, I also recently went to my moms property where I put the blazer to the test about 2.5 acres through unmaintained corn field and then down a unmaintained rocky slope and then back out being 6-8 inches of medium snow with a layer of ice underneath. I also do not believe this is my tires wearing out as they only have ~4K miles and were rotated at 3k

issue 3: not a big issue but the lights on my 3 buttons for 2hi 4hi 4lo don’t always light up and the light will randomly shut off occasionally, it doesn’t seem to effect the 4wd in any way but I thought I would bring it up.

Since I am posting this I also wanted to ask if y’all have any idea how to deal with the car shop that “fixed” my 4wd the first time. (Look into my older post for more details). Basically they charged me double what they quoted and told me that it would fix all my 4wd issues (I’m in PA). Also I know some places they can’t charge you over 10% or the quote or something but it was all word of mouth so I can’t prove it. Just wasn’t sure if I should say f*ck em and not go there again or go in and b*tch about my issues.

 

Here are some thoughts to consider:

1. Front noise:
   1. Could your front hub on the passenger side being going out?
   2. Is there weird tire wear that could be causing the noise?
2. The transfer case will split the power/torque from the output of the transmission to the front and rear axles equally. The Blazers came with open (non-locking) front differential and both open and locking rear differentials. You can tell if you have a locking rear axle by looking for the G80 RPO code on the sticker on the inside of the glove compartment. From what I know, if you have open differentials on the front and rear, it is possible that you can simultaneously get one wheel on each the front and rear axles spinning with its opposite not spinning at all if there is not enough traction such as when in snow. This would be especially so if you are in deep snow that gets under the body and takes some of the weight of the truck, offsetting the force of gravity with the result of less traction and then wheel spin. If you don't have a locking rear differential, then you might consider carrying recovery tracks. I have a locking rear axle and I still needed my recovery tracks a few weeks ago because the snow was so deep.
3. If the lights for the 4wd selector switch are going out, you might have a bad connection to the switch that is causing them to go out or your TCCM is not staying in 4wd.

Maybe someone else can give you more useful information.

 

Thanks for the reply!

As far as the front noise I was doing some more research and talked to a few mechanics I know and the census seems to be that it might be the spring not completely pulling the front out of 4wd so that occasionally it will go partially into 4wd causing the noise. There is a few threads on here about this issue. As far as a hub noise I know it is not that, because I also have a hub noise but the replacements are on their way!

I was back at the spot I was at before and just decided to do a full send and got through the snow without issue, it seems that I might’ve just found a extremely slick spot. Although it still concerns me that I only had 1 tire spinning as the rear opposite should’ve been spinning as well, but it was just the front driver side spinning. This is a issue that I will keep monitoring but as of right now I seem to be fine.

I will look into the connection of the switch, as just the like goes out but it doesn’t go out of 4wd if I am in it, usually just a click of the button turns the light back on. So next time I’m working on my car I will check the connections on the switch

still trying to see if I have any play against the shop that overcharged me for what I call a frankensteined front diff, that seems to still have issue, as they told me everything would be fixed, but I guess that’s a whole story on its own lol