Dorman 600-101 4WD Actuator Compatible with Select Models

My 1996 Z-71 K1500 would take forever to shift into four-wheel-drive, and if it was cold (i.e. when I needed it in the snow), sometimes it wouldn’t shift at all. The stock thermal actuator is a joke. My truck now shifts in less than one second and stays in four-wheel-drive if I shut it off.I wish this would have been available 19 years ago when I bought the truck for Alaska!The whole job took me about 2 hours and could’ve been less. Would not recommend splicing into the wire as the instructions state. Find a terminal in the convenience center by the emergency brake that has 12 V when the key is on. Mine was the middle pin of the one labeled DRK GRN. Crimped on a red female spade connector and pushed the brown wire onto there. I routed the wire below the oil pan and then up the driver’s side by the brake lines to a hole I already had in the firewall for trailer brakes. Secured everything with zip ties. Super happy now!!

Excelente funcionó en mi Chevrolet Colorado 2008

I have a 1995 Chevy K2500...The thermal actuator went out causing the 4x4 fuse to also blow as a result.After searching through a number of different forums, I found out about the Dorman replacement available here at Amazon.When I ordered the unit, I also purchased the associated wiring harness which is a must have as it also includes a metal spacer that you need to insert into the axle prior to adding the replacement actuator.Removal of the old unit was straight forward, as was installation of the new Dorman unit.The wiring harness plugs right in and there is a single lead that needs to be spliced into a wiring harness running to transfer case.Detailed instructions are provided however when it came to finding the wire/connector that the instructions mention, (4-wire connector C120)it got a little confusing for me as I couldn't locate it on my truck. I went back through the reviews here and found one where the person mentioned that they spliced it into a brown wire that came from the transfer case. I was able to find that wire and spliced into it without any issues, and it provided the power required for the new replacement actuator.The new unit works great, 4x4 is now instantaneous, instead of there being a lag time.Also, it doesn't appear to be effected by temperature at all.And, perhaps the best thing of all, the actuator and the harness cost less then the OEM replacement unit.Win/Win :)Update: 01/10/2023So, almost 10 years to the day this was installed it has failed. Given where we live this isn't a huge surprise, Winter environment where once in 4wd it isn't shifted in or out frequently. I've come to learn through this and other vehicles we own, if you are not activating actuators on a regular basis they just stop working. The fact that this went 10 years (even though the relative miles traveled in that time frame were low) is saying something. I still give it a 5 star review and have reordered.

Good fit 2012 GMC 2500 Sierra

I have a 1996 Silverado K1500. A few weeks ago I decided to see how long it would take for the thermal actuator to engage the front differential. The result: 51 seconds. 51 seconds?!? It was 88 degrees outside for #%/@'s sake! I had enough and decided to order this Dorman 600-101 along with the Dorman 600-600 Actuator Wire Harness. Amazon had the best price I could find and I know they have excellent customer service in case there's a problem. I received both items yesterday and performed the installation. (Note: The wire harness kit also includes a spacer that needs to be inserted into the differential before installing the actuator.) The actuator comes with sealant/thread lock already applied to the threads so all I had to do was screw it into the differential housing. (Note: 1-3/4" wrench needed).WOW; what a difference! Now my front axle engages in a couple of seconds. Not only that, but it stays engaged even when I switch off the engine. I'm definitely looking forward to no longer having to wait so long for my 4X4 to engage. I almost got into an accident once when my truck started sliding backwards down an icy hill -- and into oncoming traffic -- while I was waiting for the 4X4 to engage! Luckily the POS thermal actuator finally kicked in before I hit anybody, but I always had to plan well ahead after that incident.The only potential problem I can see with the Dorman 600-101 actuator is that it is made of nylon instead of metal (like the old thermal actuator). It is my understanding that the GM actuators are made with nylon as well, so maybe it won't be an issue. (Time will tell.) Peace.

Perfect Fit Works fast every time. Tried another cheaper one didn't work at all only about three times. Definitely would recommend this one.

The harness that matches this actuator ONLY works with this actuator, and this actuator can't be used with the stock harness. Why doesn't Dorman package them together? Together, they work great (especially compared to the OE actuator) and deserve 5 stars. But this review is ONLY for the actuator, which is absolutely useless without the harness, so I'm averaging those scores.

Fits 2006 Silverado Maxx. Works perfect so far. Looks identical to the factory unit i took off. Threads right into the front axle pointing towards the front passenger tire. My truck, for the longest time, would show the service 4x4 message. I could use 4x4 if I immediately engaged once I started the truck, but if it ran for more than 5 minutes then I would get the service 4x4 message. I had an extra selector switch that's on/in the dashboard but wasn't the problem. I changed this part along with the transfer case motor. It was also made by dorman. Now no more error message and my 4x4 option works perfectly. Word is, it's usually the transfer case actuator and not this part, but I've had this truck for years and figured what the heck, might as well do both while I'm down there.