Martinjmpr
Wiffleball Batter
(Xposted from Tahoe/Yukon forum since this one appears to be a bit more active.)
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I want to call on the GMT-800 Mafia here on ExPo for a possible/potential 4wd issue on my Suburban.
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We got a late spring snow here on the Front Range of Colorado. Got almost a foot of heavy wet slushy snow here at my house.
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On Saturday the wife wanted to look at furniture so we took the Suburban (2004 1500 LT, 4x4, about 156,000 miles on it.) Since it was intermittently snowy and slushy I put the truck into "auto 4wd." Drove all day like that until the end of the day when we were coming home through a mountain canyon with snow building up on the road, I went ahead and put it in "4 Hi" for about 2 miles so I would have sure traction. As soon as I got to the main highway it went back into Auto 4wd.
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Sunday morning driving to get gas I switched it from Auto 4wd to 2 hi (all the snow was gone and the roads were dry by that time) and shortly after that I got the "service 4wd" message. I cleared it with the steering wheel button and it did not come back on. After filling up with gas, sitting in the parking lot, I decided to run the transfer case through all modes except N (I sometimes forget that there's a neutral on these!) It went into Auto 4wd, then 4hi, then 4 lo (with a noticeable "clunk" shifting to low) and then back to 2 hi. No problems, no warning messages and no indications that something wasn't right.
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Is this something I need to worry about? Is there something I should be checking? I didn't really test out the 4wd, just made sure the dashboard buttons worked, and they worked fine.
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If I understand there are 3 potential points of failure in the 4wd system: The button on the dash, the encoder motor on the T-case and the fork on the front axle that engages the axle to the wheel. Is that correct? And if so, are there specific symptoms for failure of each component? I have heard of the dashboard button going "haywire" and not working correctly (as in, showing the vehicle is in 4 low when it is not in 4 low, showing neutral when the vehicle is able to move, etc.) As I understand it, that usually is fixed by replacing the dashboard button. For other failures, I'm not sure what the symptoms are.
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Thanks in advance! I may be doing some mild 4 wheeling this coming weekend so I want to make sure the 4wd system is operating correctly.
.
I want to call on the GMT-800 Mafia here on ExPo for a possible/potential 4wd issue on my Suburban.
.
We got a late spring snow here on the Front Range of Colorado. Got almost a foot of heavy wet slushy snow here at my house.
.
On Saturday the wife wanted to look at furniture so we took the Suburban (2004 1500 LT, 4x4, about 156,000 miles on it.) Since it was intermittently snowy and slushy I put the truck into "auto 4wd." Drove all day like that until the end of the day when we were coming home through a mountain canyon with snow building up on the road, I went ahead and put it in "4 Hi" for about 2 miles so I would have sure traction. As soon as I got to the main highway it went back into Auto 4wd.
.
Sunday morning driving to get gas I switched it from Auto 4wd to 2 hi (all the snow was gone and the roads were dry by that time) and shortly after that I got the "service 4wd" message. I cleared it with the steering wheel button and it did not come back on. After filling up with gas, sitting in the parking lot, I decided to run the transfer case through all modes except N (I sometimes forget that there's a neutral on these!) It went into Auto 4wd, then 4hi, then 4 lo (with a noticeable "clunk" shifting to low) and then back to 2 hi. No problems, no warning messages and no indications that something wasn't right.
.
Is this something I need to worry about? Is there something I should be checking? I didn't really test out the 4wd, just made sure the dashboard buttons worked, and they worked fine.
.
If I understand there are 3 potential points of failure in the 4wd system: The button on the dash, the encoder motor on the T-case and the fork on the front axle that engages the axle to the wheel. Is that correct? And if so, are there specific symptoms for failure of each component? I have heard of the dashboard button going "haywire" and not working correctly (as in, showing the vehicle is in 4 low when it is not in 4 low, showing neutral when the vehicle is able to move, etc.) As I understand it, that usually is fixed by replacing the dashboard button. For other failures, I'm not sure what the symptoms are.
.
Thanks in advance! I may be doing some mild 4 wheeling this coming weekend so I want to make sure the 4wd system is operating correctly.
Three potential failure points (the dash 4wd switch, the encoder motor on the T-case or the front diff solenoid) but how to isolate it? I don't like replacing parts unless I have to. 
I have an iPhone 6 so I need an IOS app.
