I have a 2003 Chevy Blazer 4x4 with an Automatic transfer case. When I put it in the Auto mode it would bind going around corners. I asked the dealer service department and they told me that not to have it in the Auto mode. The hubs lock in when you have it in auto mode. So I quite using it except for some snow condition. I got into talking to people at work and same Ford and Jeep have the same thing but they have problems staying locked in. I am wondering if the dealer told me a lie and that I have a problem with the hubs in the auto mode. Could I get it fix to when the vehicle detects slipperage that the hubs only locks in?

 

I would start by flushing the transfer case. The auto4wd transfer case is very sensitive to fluid quality. You need to use GM Autotrak 2 transfer case fluid. You will need 2 quarts to properly fill the transfer case. It will be blue in color and is only available at your GM dealer. If I were you, I would drain the transfer case and refill it. Drive the truck for 500 or so miles, then drain and refill it again. You will spend around $8/qt for the fluid, but hopefully, that is the problem.

 

is it possible that you(or someone) has the vacuum hoses reversed in the firewall celonoid? I had one once with these two hoses reversed and that was the issue. JP[&:]

 

swartlkk, I have flushed two months ago, not because of this, but it was time to. My mechanic used a synthetic fluid compable to Autotrak II. However, I don't believe the problem is in the transfer case, as the transfer case engages and disengages when it detects slipperage.
Peru Motors, I wouldn't have touched the hose, since this was a problem since I bought it. But can you tell me where to look to see if it is hooked up right or wrong and explain what to look for.

 

Have you ever had any work done to the transfer case (ie. has it ever been removed)? If it has, then there is one possibility aside from the fluid mentioned above and in my response below. That is that the front and rear speed sensor wires being reversed. The front speed sensor should have a yellow and purple wire while the rear speed sensor should have a light blue and dark green wire.

I do not know why people (mechanics) push some aftermarket alternatives with the potential to do harm to these transfer cases. The fluid choice of your mechanic could have hurt more than anything else. GM Autotrak 2 is a specially formulated transfer case fluid with friction modifiers to alleviate the exact condition you are experiencing. The clutch packs in these transfer cases are very sensitive to the type and quality of the fluid used.

 

flip flop the two hoses on the celonoid above the distributor cap(wire plug in and two small hoses). Try it and see-if no better.put back the way they were. JP[:'(]

 

swartlkk, You opened a can of worms on me now. I told my mechanic that this take special fluid(Autotrak 2). He said this fluid meet or exceeds manf. spec. for Autotrak 2. If an aftermarket puts that labal on they would have to work? If not, then I will have to have a talk with my mechanic. Should I have him change the fluid? However, I have not put it in Auto mode since the flush was done 2 months ago so I don't believe damage was done? No the transfer case has not been work since I had it. I bought it over 2 years ago at 32,900. I now have 53150 on my 2003 Chevy Blazer.

Anyone, no one told me yet if the Chevy dealer service center was wrong at telling me I am not suppose to have it in Auto mode in rainy conditions or some other time.

Thanks for help

 

Your owners manual should describe what conditions the various modes are for.

As far as not putting it into Auto4wd mode, since the flush, that does not matter. The fluid circulates through the entire system even when in 2HI. I am sorry if this has opened a can of worms, however, I am mentioning this in your best interests. I would like to know what fluid it was that he used and what manufacturer specs they met. I would bet that the manufacturer of this fluid has no such claim.

The last that I had read (can not find it now), GM has not released the license on the fluid. FYI, Autotrak 2 fluid is synthetic as well.

Royal Purple is trying to push their SynchroMax manual transmission fluid (for manual transmissions that use ATF fluid) for use in these transfer cases, but I could not find anything to confirm that it met or exceeded GM Autotrak 2 fluid specifications on their website. Also when I called their tech line specifically asking about AWD and Auto4wd transfer cases, they were shifty to say the least. When directly asked if it met the requirements of GM Autotrak 2, they stated that they had no documentation, but "all of their fluid exceeds the manufacturers requirements for the intended application" which seems like a regular company line and a redirecting, political type response.

I have seen the Autotrak 2 fluid being described as is a high friction modified ATF fluid so at some point, one would think that someone would be able to copy it, but without knowing what to test to, how do you know you got it correct?

Is it worth it to use something that you are unsure of? I can see if you were some place where chevy dealers were reluctant to order this type of fluid (ie, not US or Canada), but if I could get it, you would bet that I would be using it.

 

In my manual it pretty much says, When in engaged in AUTO 4WD, the front axle is engaged, but the vehicles's power is send only to the rear wheels. When loss traction it will send to front wheels.
That explains my situation and it is suppose to be that way. The dealer was right I will half to say. Case closed on that one. And now I can concentrate on the fluid issue.
And swartlkk thanks for bringing my fluid use up. I am going to investigate that and strick up a deal if turns out to be not good.

 

I have talked to my mechanic. After some more research by and recalling everything that occurred that day. The fluid they used does meet Autotrak 2 specs. It is Wolf Head Super Universal Sythetic ATF. He also told me he does check stuff out, because if he don't then he will be held liable for it. I called tech support at Wolf Head and they told me the same. So here is one aftermarket product that does meet.