Engine/Transmission (1994 - 1998) 1995 Dodge Ram CTD with 4x4 trouble - its still winter here

[SBoyak]

I have a '95 Dodge Ram 4x4 with only 110,000 miles on it. I went to put it into 4WD today, and nothing happened. It just stayed in 2WD when I put it into 4Hi and 4Low. (only the rear wheel continued to have power, nothing in the front). There was no grinding or anything. If anyone has any advice on where I should begin, I would appreciate it. Live in a rural area, so not too many options for repairs, would just like to know what to expect.

Thanks

Sean

 

[JR]

Crawl under your truck and inspect the vacuum lines that supply the vacuum actuator on the front axle. If theyre both still attached to the actuator, trace the lines backwards and make sure theyre not rotted out. They should wrap around up to the top of the t case. Next, with the truck running in park or neutral with the wheels blocked/ parking brake installed so the truck CANT ROLL pull the rubber lines off at the actuator. There should be vaccum with the truck in 2wheel drive to one line and when switched to 4whl the other line should have vacuum. If you dont have anything you will have to follow the lines backwards until you find the problem. If you do have vacuum and still no 4whl drive you may have a fork hanging up or more likely the actuator froze or corroded. thats no big deal either, but thoroughly check everything above first, most of the time it is a simple issue like I described above. I see your in Michigan so we are probably in the same boat with the calcium chloride on the roads. Some vehicles around here thats been driven heavy in the winter time for several years, you can crawl under them and parts and pieces will literally be hanging by a thread the cancer is so bad Here one day, gone the next!

 

[mwilson]

With the engine running cycle the heater controls from defrost to floor to dash and back slowly.



Does the air flow change as it should??? If not you may have a vacuum leak under the hood.



Being older and smarter Dpossibly even lazy. . ) I would check that first before even crawling under the truck.



Mike.

 

[SBoyak]

Hey, Thank You JR in Andover. . I will check those lines first thing in the a. m. !!

 

[JR]

With the engine running cycle the heater controls from defrost to floor to dash and back slowly.



Does the air flow change as it should??? If not you may have a vacuum leak under the hood.



Being older and smarter Dpossibly even lazy. . ) I would check that first before even crawling under the truck.



Mike.

Yep, you definitely are more smarter than I is... :-laf:-laf

The defrost trick could work if they share a common line, most likely youll still wind up on yer backside in the snow, unless youve got a cozy garage to work in...

 

[mwilson]

Yep, you definitely are more smarter than I is... :-laf:-laf

The defrost trick could work if they share a common line, most likely youll still wind up on yer backside in the snow, unless youve got a cozy garage to work in...

Seriously though, my thought process is that will tell if you have a break between the vacuum pump and the firewall. On a 95 the main feed goes from the pump to the firewall, then tees off to feed the various functions. At that age the boot connection to the pump may have rotted off or the plastic main line may be cracked. A lot of folk in cold climates tend to leave the heater controls on defrost (which is the default position with a loss of vacuum by design) and either never use the cruise or don't have it in the first place. As a result they don't realize that there is a problem until the 4wd refuses to engage.

I figured it would be an easy place to start. I have had several go arounds with the vacuum systems on 2nd gens and my first weapon of choice nowadays is a mighty vac.



It still may turn out to be a rusty shift can rusted off and swinging by the lines. . :-laf



If the heater functions as it should I would then get under the truck and check at the connections as you suggest (while laying in the snow on my back)



Oh look, everything I just typed is all fuzzy... . I Luv VicodinOo. Don't leave the Doc's office without it!!!



So in conclusion I'm not any smarter, just a little more stoned...



Mike.

 

[JR]

Good call, Mike. Always thinking, unlike me. Im notoroius for jumping in head first (or in this case on my back :-laf)

I prefer my Vicodin with a couple of cold ones, the warning label on the bottle doesnt know what its missing :-laf

Makes the snow feel a whole bunch warmer :

Hope your shoulder gets to feelin better

 

[Bob4x4]

Stuff like that makes up for some of the Cali short comings. We normally see someone just installed the vacuum fitting wrong at the transfer case switch here-rust free So Cal

 

[rMetzger]

So, how'd it turn out? If you discover that the actuator can is shot, you can either replace it OEM and wait for it to fail again, get a Posi-Lok, which is really neat. The Po'Boy solution, which you can do almost for free is this: remove the CAD housing, which will give you access to the coupler-sleeve, slide it all the way to "engaged", and either wire it in place (do a neat and tidy job, so as not to have it rubbing the inside of the axle housing), and have some crummy MPG until you can fix it one of the "right" ways. The permanent, near-freebie "fix" which would mess up your MPG forever, would be to put a couple of small tack-welds on the sleeve and axleshaft to prevent ever disengaging again. then, just replace the CAD housing to close it all up. Easy-peezy..... Another guy had a similar problem, and one of the contributors had seen it a lot of times. Unfortunately, he'd also seen a lot of chewed-up splines that would keep the system and ANY fix from being reliable... Let's hope that's not you.