Does this happen to anyone elses truck?

So, today we got our first good snow... icy and all that... I have to use 4wd on the truck to get anywhere decently, and it works great... but there are also those spots where they salt the road and its just wet... well my truck handles, and feels hideous on just wet pavement when its in 4wd, but when im on wet pavemnt and I take it out of 4wd it doesnt come out... I have to drive around for atleast a mile then it will go CLUNK and fall out... If im at a stoplight I can usually go into reverse and it will pop out, but I dont think that I should have to do that.
I do alot of offroading, and when im on dirt or wahtnot and i take it out of 4wd it comes out almost instantly.

I cant really take the truck out of 4wd before I hit the salted patch of road, becasue the salted roads are always the faster moving roads and I need the 4wd to get off the side road thats covered with ice to get moving on the fast road...

What do yall do?

Also, I cant drive in the snow in 2wd becasue I killed my rear diff and its ***... it will ONLY spin n damn tire and that gets me going nowhere... im gunna throw a locker in there but I dont have it yet.

I know the 4wd is controled by vaccum, so maybe I havea leak and its not enough vaccum to pull it out of 4wd fast... is there any tricks to getting the damn thing out of 4wd?
Its done this ever since I owned it...

I know its stupid, but I have never touched the transfercase fluid and its got 90,000 miles. Should I drain and refill the transfer case with a thinner fluid to try to make things less "sticky"?

I REALLY wish I had the transfer cases that some of them jeeps have... With a selectable parttime, and full time 4wd.

 

This is kinda similar to how my transfer case behaves, except for the clunk. When I go into 4x4, it goes in immediatly. When I come out, it can sometimes take a little bit of driving before it comes out. Usually it is only 50-100ft, but sometime it can be a little more. It never clunks when it comes out though. In fact, sometime I think I am actually out of 4x4, but I am just waiting for the 4x4 indicator to go out.

I'd say it would indicate that you have weak vacuum. Changing the fluid is definetly a good idea in your case I think, though not sure if it will help fix your particular problem. Changing the fluid is easy to do to.

I would also suggest that you try putting some weight in the bed of your truck. Granted, I have a limited slip rear, but I almost never use 4x4 on icy roads because I just find it unnecessary. The only time i use it is if I am going to be stopped on an uphill incline, and need the extra traction to get moving. I put about 400lbs in the bed, and find that to be a pretty good balance.

 

Yes, I have a 400lbs weight... which reminds me I should stick that in now before work...

but, it donesnt help all too much.
Going ANYWHERE in 2wd is horrid on my truck, even taking of really lightly it will start spinning at any given time... but the spidergears are real bashed up in the back, and it only likes to transfer the power to one tire... so I understand that...

Let me explain the "cluck" alittle more, it only cluncks when it comes outon wet pavement, if there is snow it will always pop out quietly. It also goes in quietly, and instantly.

I just went out and played with it on a road that is half snow, and have wet pavemnt... it goes in fine as usual, but if I take it out of 4wd the light goes off almost imediately but stays in 4wd like I said before...
These are the ways that work everytime in my test (and I tested this like 20 times each) if im at a stop put it in reverse, hold the brake and give just a touch of gas got it into 2wd everytime... Also, If I take it out of 4wd and turn a corner it always pops out... but in a staight line it likes to wait.
I did exadurate when I said it took a mile to come out of 4wd if im going in a staight line... its more like 50-200 ft usually... but this last time it took a good 1/4 mile and dident pop out untill I turned a corner.

I dont really have anyproblem running my truck in 4wd on wet pavement under 55mph, but my trackbar is trash from all my offroading and the way that the front axle and rear axle bind when its in 4wd must shove the front axle over (becasue the track bar is bad) and it makes my steering wheel go at a angle when im going straght... if that makes since.
When its in 4wd and on snow, my steering wheel is normal to how it is when its out of 4wd. Im confident that its the track bar casueing that problem becasue everything is really tight in my front end other than the trackbar, and the shocks... which are both like I said... trash.

So, you think that its low vaccum that is casueing this? Ill look around make sure I see no leaks... any other ideas?

 

mine used to do that with the vacuum cad. it might be related to weak vacuum, or maybe wear on the front axle or collar or bushing or maybe stickyness in the cad shaft, or something. anyway, my 4wd light would go out because something would move enough to trip the light, but yet the shift fork/axle collar would not move enough to let go of the axle. i suppose because there was too much pressure on it. i could tell by the 'sound' that it was still engaged. if i'd stop, or back up, the collar would slide over enough to let go.

i wanted a posi-lok anyway, so i just went that way. i can still feel that same resistence pressure now when using the posilock push/pull button. i have to feather the speed/pressure to get it to slide. but now at least i know where its at.

so, i'm just guessing that it might be wear. i think there is a bushing on that axle shaft, and if its wollered out some, that would explain it.

my posi-lok is really not any good for coupling/uncoupling on the fly at speed. but i'm wondering that if you had one, and you engaged the posilok and left it there, now you have locked axles with an open differential. (same as locking hubs). then you could shift t-case to/from 4 hi/low as you needed, and just leave the axles locked ???? edit... i guess thats a stupid idea because that's exactly what you are already experiencing... t-case disengaged and axle still coupled up.

edit.. correct a couple mistakes

 

Ya, maybe its wear... who knows...

Its not too annoying, now that I have a way that gets it out every time.

Ive had the cad cover off before when I had to replace the gasket and everything looked perfect... but who knows.

 

hey just a thought. when you shift out of 4wd at the t-case, then the front drive shaft and differential is released from engine power. cad vac is supposed to uncouple. but even if it doesn't, does it really matter ?

since the t-case is no longer pushing power, you won't get the rear/front binding that occurs. if the axles are still locked, then the spider gears will rotate as needed to allow the differentation. if may feel a little different, but it won't hurt anything.

 

this link is to page 3 of a pretty good article on how a differential works. scroll down a little bit and click between the 'straight' vs 'turn' to see the spider gears in action.
http://auto.howstuffworks.com/differential2.htm

 

I agree. I think you're losing vacuum and need to replace the CAD. I had something similar. I went with the Posi-Lok.

 

Hello to all. I'm new to the forum, it seems to be a good spot for some help and info. I have the same problem when I shift out of 4wd on pavement and it wasn't a vacumn leak or cad unit problem for me. I found that when you shift into 4wd the shift collar will slid and connect the passenger side axle shafts, all while the t-case transfers power to the front axle. Once the couper is connected and power supplied thier is a load on the coupler keeping it from dissengaging as quickly as it engaged. When you shift out of 4wd and stop the power to the front axle the rolling resistance while moving is still binding the coupler. That is why when you stop and shift into reverse or turn a corner and allow the two sides of the axle to spin at different speeds it releases the bind and the collar slids back to its 2wd position. When off-road, loose dirt has more slip than pavement so it canshift out of4wdquicker than even on wet pavement. At least that is what I have found to be the case in my situation.

 

I dunno... Ill work with it a little bit just to see if I have a vaccum leak or somthing...