4x4 not working - axle actuator issue

[jysp]

[SIZE=medium]Back in 2010 using help from the other site I was able to track down and fix a bad disconnect. I ended up buying a rebuilt disconnect and a new actuator. The 4x4 worked great that winter…[/SIZE]

[SIZE=medium]I live in Winnipeg Canada; and have a 4x4 for winter I don’t much in other seasons. Every year my 4x4 stops working when it gets cold. When I turn the selector from 2WD to AWD the indicator light just blinks for a time and then stops BUT I’m still in 2WD. I hear the actuator motor working but it does not seem to engage the disconnect. [/SIZE]

[SIZE=medium]Using [/SIZE][SIZE=medium]http://forums.trailvoy.com/showthread.php?t=46356[/SIZE][SIZE=medium] (thanks Roadie):[/SIZE]

• [SIZE=medium]I took the actuator off then turned the selector and the actuator seems to hesitate while extending. Using a socket extension I have manually pressed the fork in activating the disconnect when I turn the drivers side front wheel I can feel that the 4x4 is activated. [/SIZE]
• [SIZE=medium]I pulled the actuator apart and see that there is some type of oil/grease over the contacts that the fingers touch as the actuator gear tracks up and down. I have cleaned the contacts and re-assembled. The 4x4 system works fine for a while. [/SIZE]

[SIZE=medium]Last winter when it started to get cold I had the same issue. I didn’t have time to pull it apart again to clean it, so when I turned the selector to AWD and it started to blink I drove with it blinking, sometimes over the course of the drive it would engage but not all the time (probably <50%). Unfortunately when I turn the vehicle off the actuator disengages, so when I start the vehicle up the next time with the selector in AWD position the actuator has to engage again. Most of the time I would get the same issue. [/SIZE]

[SIZE=medium]With Winter coming soon I thought I would see if there is a better fix than cleaning the actuator a couple times over the year. I really don’t I think I should have to. Does anyone else have this problem? [/SIZE]

[SIZE=medium]Thanks,[/SIZE]
[SIZE=medium]Jerry[/SIZE]

 

[The_Roadie]

Glad I could help you for a while. Dorman makes an aftermarket actuator and I haven't heard any bad reports about it yet. Perhaps they changed the finger design, or use different grease or maybe their grease stays where it's supposed to instead of the GM design.

Especially if you have one where the grease congeals when cold, I'd be taking it apart one more time and not just cleaning the contact fingers, but removing all grease I could, and putting in a smaller amount of red synthetic. Same stuff that works so well to rebuild the disconnect mechanics with.

 

[linneje]

I don't see in your post where you discuss the type of grease that you used in the repair. The GM recommended molybdenum grease gets really thick in cold weather. I was recommended a lithium based lubricant (made for snowmobiles I think) and I have never had a problem since I did my rebuild and put it in. I would caution, though, I basically never used the 4wd in the summer, I only need it in the winters here. It will get real thin in hot weather.

I think Roadies suggestion is a good one too - little chance of grease leakage if you take his advice with the red synthetic and use less than GM packs in with the moly stuff. I know because I completely cleaned my disconnect and it was packed full of moly. The pictures I have seen with people using red synthetic in small quantities on the contact surfaces.

 

[jysp]

just to confirm:

Roadie - you are talking about taking the actuator apart, cleaning it and putting a little red synthetic grease on the gear side of the actuator?

linneje - are you thinking it may be that the grease in the disconnect is to thick which is keeping the actuator from fully extending?

 

[linneje]

I am thinking that is the grease in the disconnect which is too thick in the winter, but it is being accentuated by grease on the contacts which is increasing the resistance and therefore the actuator is operating on less current.

So it is actually some of both which I believe is your problem. Is it moly grease in there????

 

[PProph]

Another point of note is that it's recommended to avoid using the a4wd and just go into 4hi if you feel it may be necessary. I didn't see anywhere in the op where you tried switching to 4hi, are you only having trouble with a4wd? There are few instances where I'll actually use a4wd, I don't like the idea (even if supposedly designed that way) of parts engaging at speed.

That's obviously not to disregard anything these other much more knowledgable members are telling you, just thought I'd throw that tidbit in.

 

[The_Roadie]

Good point - I skipped over that detail. A4WD mode is of very, very limited utility on surfaces that go from high to low traction and you're driving too fast for the low traction conditions or need to accelerate quickly such as joining a main road that's dry from an icy/snowy side street.

That said, the transition from 2HI->A4WD is good for listening to the actuator and encoder motor noises, and the A4WD->4HI transition should ONLY make the encoder motor noise.

 

[jysp]

I bought a re-build disconnect so I'm not sure what kind of grease is in it.

When this happens I can't get into 4HI either. I don't remember exactly what happens to the indicator light.

Thanks for the comments about AWD and 4HI. I will keep this in mind this winter.

I will try to clean the and re-grease the actuator first to see if it helps. If that does not help I guess I will have to break down and re-pack the disconnect.