Please; need help from the fine Chevrolet people here!

[Larry E.]

The following does not apply to Corvettes but I'm sure with the knowledgable people on this board someone will know. Here we go:

I will be trading my 2003 4WD Trailblazer(50000 Miles) for a new Silverado.(Shortbed) Everything was going fine with the deal until they
took my T/B out for a test drive. They came back and told me my 4 WD does not work. No warning lights are lit up on the dash. They (Chevy Dealer) said they test to see if working on a non-slippery surface (Summertime) by making a "Crazy Eight" with the 4 WD turned on. If it grabs it
is working if not >not working. The last snow (not long ago) it worked fine for me. Of course this will effect the deal we make. They think the
clutches are not grabbing now and a simple flush for new gear lube may work. If not they said it could need new clutches and would cost
about $1000 for the work. Is this true what they are saying? All comments are welcomed. Larry

P.S. I have never changed the gear lube in the unit; as the truck has a little over 50000 mile on it. Should the lube should have been?

[Jim D.]

Re: Please; need help from the fine Chevrolet people here!

I can't help you with the 4WD issue but I can tell you that you'll be way ahead of the game if you consider EVERYTHING a car salesman tells you is a lie. When I bought my new truck they told me so much B.S. it wasn't funny. I had one tell me that if they sold it to me for less than MSRP they would lose their GM franchise. Try asking your question on a Trailblazer forum like - http://www.trailvoy.com/ My ex was the General Sales Manager at a large Chev. dealership for years. The stories she told me of what the sales people did made me sick.

[Larry E.]

Re: Please; need help from the fine Chevrolet people here!

Jim: The people I have been dealing with are pretty good straight shooters. It was a mechanic that took it for a test drive not the salesman. I have put this on
the truck forum also. BUT I TRUST THE OPINION FROM OUR EXPERTS MORE THEN THEM. I come to the conclusion a long time ago that the people here know
more about Chevrolets then anybody else. Larry

[Edward J.]

Re: Please; need help from the fine Chevrolet people here!

Larry, have you had the 4x4 computer dia. done, they will store trouble codes if something is up electrically. When you flip the switch to manual 4x4 while sitting still you can sometimes hear the electric motor move. another thing does the yellow light on the 4x4 switch flash for a moment and then light up solid? They really seem to be a pretty good system. I have had one 4x4 module problem at my shop. which is a replaceable part.

[Jack H.]

Re: Please; need help from the fine Chevrolet people here!

Larry,

I too have a 2003 Trailblazer 4WD, wife's car. It has over 100,000 miles, I've never changed the 4wd gear lube (not proud of that), and the wife uses the 4WD a fair amount here in Ohio. Just want to be clear on a couple things. I have a heavily optioned LTZ-NorthFace Edition with electronic drive selector and not sure what you have so this may or may not be the same for your vehicle. My SUV has selections for 2WD, 4WD-Hi, AWD, and 4WD-Low. There is NO mistaking in dry condition whether or not the 4wd is working, but it depends on which selection. In dry conditions, putting it in 4WD-Low and going into a turn on dry pavement, it's like you are applying the brakes hard, i.e. vehicle will literally stop if generous throttle is not continuously applied. 4WD-Hi is similar but not quite as extreme since the higher gearing makes it a little less obvious. In AWD drive, it is NOT NEARLY as evident. So my question is...can't you yourself tell 4WD is working or not by trying 4WD-Low or 4WD-Hi on dry pavement? Also are you sure the dealership isn't trying to either pull a fast one or otherwise accidentally testing with AWD where it's not as evident?

Maybe what I wrote is trivial and already known, but just wanted to clarify and be sure.

Another 2 cents is that if the 4WD is indeed not working, I'd be surprised if simple fluid change would fix it, but certainly the cheapest thing to try. I'd also guess that if you have an electronic selector, that an electrical problem could be at fault and that COULD be fairly easy/cheap to fix in comparison to replacing clutch packs.

If there is something you want me to try with mine, compare, or whatever/however knowing someone with a similar Trailblazer could be beneficial, let me know with reply here or email me at henge <at> fuse <dot> net.

I wish you good luck and hope it all works out. I love the new Silverado models and would like to pick one up myself, but I'll keep driving my beater pickup ('98 Chevy K1500) while it lasts.

[Christopher P.]

Re: Please; need help from the fine Chevrolet people here!

Could you put it up on jack stands and or on a frame lift, engage 4WD, and see if it is working?

[Larry E.]

Re: Please; need help from the fine Chevrolet people here!

Larry, have you had the 4x4 computer dia. done, they will store trouble codes if something is up electrically. When you flip the switch to manual 4x4 while sitting still you can sometimes hear the electric motor move. another thing does the yellow light on the 4x4 switch flash for a moment and then light up solid? They really seem to be a pretty good system. I have had one 4x4 module problem at my shop. which is a replaceable part.

Ed: Thanks for the response. Have not had the 4 x 4 computer dia as no indication of trouble. Yes when I flip the switch the yellow light does flash for a moment
and then the light is solid. FYI Larry

[Larry E.]

Re: Please; need help from the fine Chevrolet people here!

Larry,

I too have a 2003 Trailblazer 4WD, wife's car. It has over 100,000 miles, I've never changed the 4wd gear lube (not proud of that), and the wife uses the 4WD a fair amount here in Ohio. Just want to be clear on a couple things. I have a heavily optioned LTZ-NorthFace Edition with electronic drive selector and not sure what you have so this may or may not be the same for your vehicle. My SUV has selections for 2WD, 4WD-Hi, AWD, and 4WD-Low. There is NO mistaking in dry condition whether or not the 4wd is working, but it depends on which selection. In dry conditions, putting it in 4WD-Low and going into a turn on dry pavement, it's like you are applying the brakes hard, i.e. vehicle will literally stop if generous throttle is not continuously applied. 4WD-Hi is similar but not quite as extreme since the higher gearing makes it a little less obvious. In AWD drive, it is NOT NEARLY as evident. So my question is...can't you yourself tell 4WD is working or not by trying 4WD-Low or 4WD-Hi on dry pavement? Also are you sure the dealership isn't trying to either pull a fast one or otherwise accidentally testing with AWD where it's not as evident?

Maybe what I wrote is trivial and already known, but just wanted to clarify and be sure.

Another 2 cents is that if the 4WD is indeed not working, I'd be surprised if simple fluid change would fix it, but certainly the cheapest thing to try. I'd also guess that if you have an electronic selector, that an electrical problem could be at fault and that COULD be fairly easy/cheap to fix in comparison to replacing clutch packs.

If there is something you want me to try with mine, compare, or whatever/however knowing someone with a similar Trailblazer could be beneficial, let me know with reply here or email me at henge <at> fuse <dot> net.

I wish you good luck and hope it all works out. I love the new Silverado models and would like to pick one up myself, but I'll keep driving my beater pickup ('98 Chevy K1500) while it lasts.

Jack: Thanks for some idea's. That dealer will change the fluid on Tuesday and will go from there. Larry

[Jeff P.]

Re: Please; need help from the fine Chevrolet people here!

Larry,

Try this test. Put the T/B is 4wheel drive and drive forward and turn left or right, does it feel like the brakes are on? This should be done with speeds under 5 mph. What this mechanic is saying is the clutches in the differential are bad, not the 4wd. The gear lube could be changed but still needs the posi additive added to the lube. I dont think this salesman should be saying the 4x4 is broken, if when you are in motion with the 4wd engaged and turn right or left it feels like the brakes are being applied. This test is on dry pavement. Be careful with salesmen like this. Try the test so you know for your self. That Trail Blazer is still worth cash being 11 yers old and 50000 miles. He's trying to make a quick $1000.

[Larry E.]

Re: Please; need help from the fine Chevrolet people here!

Larry,

Try this test. Put the T/B is 4wheel drive and drive forward and turn left or right, does it feel like the brakes are on? This should be done with speeds under 5 mph. What this mechanic is saying is the clutches in the differential are bad, not the 4wd. The gear lube could be changed but still needs the posi additive added to the lube. I dont think this salesman should be saying the 4x4 is broken, if when you are in motion with the 4wd engaged and turn right or left it feels like the brakes are being applied. This test is on dry pavement. Be careful with salesmen like this. Try the test so you know for your self. That Trail Blazer is still worth cash being 11 yers old and 50000 miles. He's trying to make a quick $1000.

Jeff: Thanks. On this test should the 4 Wheel drive be in "Low" or "High"? Will this test tell us anything about "AutoMatic 4-Wheel" Drive? This is almost all I ever used and during the last snow (7 Weeks Ago) is worked perfect. I have never used the High or Low All time 4WD. Comments? Larry

[Jeff P.]

Re: Please; need help from the fine Chevrolet people here!

Larry,

Try this test in 4wd high. Low lock is for climbing hills off road. Then put in 2wd and do 10 figure eight loops, this will free up the stuck clutch pacs in the rear differential. Good Luck.

[Larry E.]

Re: Please; need help from the fine Chevrolet people here!

Larry,

Try this test in 4wd high. Low lock is for climbing hills off road. Then put in 2wd and do 10 figure eight loops, this will free up the stuck clutch pacs in the rear differential. Good Luck.

Jeff: Thanks much; will do; will report to you what I found. Larry

[Edward J.]

Re: Please; need help from the fine Chevrolet people here!

Ed: Thanks for the response. Have not had the 4 x 4 computer dia as no indication of trouble. Yes when I flip the switch the yellow light does flash for a momentand then the light is solid. FYI Larry

Larry, I guess the next logical step would be to have someone turn the switch to the 4x4 mode and if you know were the transfer case just turn the key into on position and lay down is listen for the electric motor to operate. I really would not spend any money on changing out the fluid yet until you really know just what's wrong. The fluid change is not going to be your problem, at this point Its ok to do it as preventive maint. only. All dealerships have the abililty to go into the computer systems and run bi-directional controls of items, I am not sure if the 4x4 control module motor has that capability.

[Larry E.]

Re: Please; need help from the fine Chevrolet people here!

Jeff: Thanks much; will do; will report to you what I found. Larry

Jeff: I tried your test in 4WD "HI" did a turn under 5 MPH and it did feel like the brakes where applied. I will talk to the dealer tomorrow. BTW does anybody
know of a test for the Auto-4WD on dry pavement? This is the one I use in the snow and it has always worked.Larry

[Patrick H.]

Re: Please; need help from the fine Chevrolet people here!

BTW does anybody know of a test for the Auto-4WD on dry pavement? This is the one I use in the snow and it has always worked.Larry

I don't think there is one. In my 2003 pickup and my business partner's 2004 Suburban, the wheels have to slip before the Auto 4WD will engage. In fact, this is my partner's complaint is that it HAS to slip for it to engage.
Generally you will feel zero difference driving it around in daily life, so if their problem is with the Auto 4WD then they don't have a clue how it really works.