'97 Sierra 1500 4x4. No trouble codes in transfer case control module. I can hear the transfer case shift. I can fell that the transfer case goes to 4 low. But push button indicator lights keep blinking - which means front axle is not engaged. I suspect the 'thermal actuator' is not working, and thus the front axle is not engaging. Sound right to you? Is something else more likely? Thanks, Cal
4x4 not working?
May 20, 2006
16 Replies
Is it going into four wheel drive?
As I meant to say, I can tell by drivng that is IS definately going into
4 low. Not sure positive that case is going into 4 hi, but it seems likely given that 4 low works, and I can hear the transfer case shift when I push the button. According to the book, blinking lights mean the fron axle has not (yet) engaged.
If there is question about 4hi working then that point to front axle disconnect as it must engage for light to stop blinking. THe engaging of low range or 4hi in Tcase is a seperate function from front axle engaging. Low range can engage without front axle engaging.
----------------- The SnoMan
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the thermal actuator is a problem and should be replaced with the newer type which has a motor driven engagement.
1 hour to replace easy and about 100 bucks. works great and is well worth it if that is your problem. old john
Is the motor driven actuator a direct, screw-in replacement? Do you happen to have a part number? Thanks for the info. Cal
I just replaced the actuator in my 1997 K1500 Z71 3 weeks ago. Actuator part #26060073. You will need a new small wiring harness as well - part #12376317. I get employee discounts through my sister & pick up the parts at a GM warehouse. Actuator - $79.18. Harness - $25.51.
Fantastic. Thanks. The actuator just screws in where the old one was?
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a site for you...........
http://72.14.209.104/search?q=cache:d1wAAzzEomMJ:
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~:~ Marsh ~sips his crownroyal.....mmmm......good~ ~:~
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a site for you...........
http://72.14.209.104/search?q=cache:d1wAAzzEomMJ:
formatting link
~:~ Marsh ~sips his crownroyal.....mmmm......good~ ~:~
THe thermal actuators are not known for long service life. Some time around 1997 or so GM switch to a servo driven actuator that is more relaible. It can be retrofited to a earlier model.
----------------- The SnoMan
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Yes and you install a modified control harness for it and you are done.
----------------- The SnoMan
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Yes, they also give you a small steel spacer that must be inserted into the axle before you screw in the new actuator.
Thanks for all the help. btw, when I look up part 26060073 on gmpartsdirect.com, it states must also get part 88959465 -- which is a 'harness K', same description as 12376317. Perhaps a slightly newer, and more expensive, version. Thanks again.
Actually, I was told that there are 4 different harnesses available. I should have mentioned that, sorry. My truck has the 350 Vortec engine with the 4L60E transmission.
Here's the proof. +12v at the actuator connection in 4 wheel. Actuator gets warm. But front wheel continue to rotate freely. Possibly I should have done this first --- but this way I got the right replacement part numbers! Thanks. Cal
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