Four wheel drive actuator slow to engage

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df2x4

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The thermal actuators do tend go out at the most inopportune times. Which is why god (or GM) invented the electric actuators.

This was definitely the case for mine. There was about eight inches of snow on the ground and I had just hopped in the truck to go somewhere. :lol: I can't be too upset at it though, that original thermal actuator lasted over 20 years.
 

alpinecrick

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This was definitely the case for mine. There was about eight inches of snow on the ground and I had just hopped in the truck to go somewhere. :lol: I can't be too upset at it though, that original thermal actuator lasted over 20 years.

That's impressive. In 275K miles on my 91 Light K2500 I'm pretty sure I replaced mine 3 times.
The 96 K1500 went out at least twice in 200k miles. I didn't wait for my 97, it had a 135k when I bought it, had the thermal still in it, but I installed an electric one first thing......
 

alpinecrick

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As an added note, if either actuator is taking a long time to engage, a guy may want to change out to fresh front diff fluid.

GM, in an attempt to address thermal actuators burning out, had a bulletin recommending synthetic fluid be installed in the front diff. My 01 Sierra's manual specs synthetic fluid in the front, conventional in the rear. I initially couldn't figure why, thinking it was possibly a different design in the front diff. But the GM parts guy said the synthetic fluid bulletin/specs were because of the actuator burning up in cold weather because of multiple attempts of the thermal actuator to engage.
 

98chevy2500SS

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Depends on how cold it is outside, but anywhere from 10 to 30 seconds I'd guess.
Ah ok, so mine must be fine then. I hear the actuator sound right when I push the button, but the light flashes for about 8 seconds.
 

98chevy2500SS

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As an added note, if either actuator is taking a long time to engage, a guy may want to change out to fresh front diff fluid.

GM, in an attempt to address thermal actuators burning out, had a bulletin recommending synthetic fluid be installed in the front diff. My 01 Sierra's manual specs synthetic fluid in the front, conventional in the rear. I initially couldn't figure why, thinking it was possibly a different design in the front diff. But the GM parts guy said the synthetic fluid bulletin/specs were because of the actuator burning up in cold weather because of multiple attempts of the thermal actuator to engage.
I should probably change my diff fluids just for the hell of it before the cold weather rears it's ugly head again, I'm sure they are past due for a fluid change.
 

Blazer92

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there is a harness that converts it from thermal to electronic, but it's almost the amount of money just to buy another thermal one,

I felt the same way about price so I found a converted one at the salvage yard took the actuator and harness for way less than new, think it was $40 for both
 
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