Recently my front axel would not engage after placing the TC into 4wd, light on dash was on. I check the front actuator for good vaccum, in which it had to I know the stock actuator is shot. Before I could by a new one my right front hub went out replaced it, now the dash indicator light doesnt come on when I out the truck into 4wd. The TC goes into high and low fine and works but the front axel just doesnt lock up.

My question is the dash light, big deal or no? I will be replacing the actuator after Christmas and was just curious if the light could not be working for another issue like the vaccum switch on the TC.

97 2500 127000
5 speed
Brooks

 

My guess is that your Vac actuator is shot,

I would go ahead and check everything just to make sure that all is well one more time. I have had the same problem and when ur 4wd fails when u need it, its just plain sucks..... anyways....Are all of your vacuum hoeses connected? IIRC the 97 has hydroboost on it, but the 4wd still works off of Vac power, Id check these things in this order

1. the connection above the T case, i know on my 96 it is a little four way prong that only goes in one way, check it to see if it has oil, or if it has come loose

2. (if applicable) check all of the vacuum lines going to the actuator, make shre that they are clean, dont have oil, and properly connected. Every so often the little rubber grommet connectors will go bad, get oil, or rot out and need replacement

3. Take apart the CAD and see if it actually moves freely, its no big deal to do this, 4 7/16 bolts and a breather line and off it comes, If it moves freely then u can go check the vaccum to it..

4. With the truck on, one of the little lines should have vacuum if all is well that will pull the collar and keep it at 2wd, IE this line is sucking air, In 4wd the other line should blow out air and push the collar over the little shaft to enable the 4wd to work..

5. If you have done all of the above and u are certain all is correct and in proper working order, Your vac actuator probably went bad.. Two things u can do here, One go find a Vac actuator for about 85 dollars at a dealership or two, do what i did...

6. POSILOCK it and forget it!

Now about your light, simply said, the little electronic connections on the Vac Actuator are probably grounding out, or the connection has water in it, or might not even be on there at all, U might wanna check the fuses on the truck one of them might be for that 4wd light....

HOpe this Helps

Rick

 

There used to be a quick and easy mechanical fix to convert from Vacuum to cable operated, or at least suplemented. This gave a positive mechanicl connection via a cable and linkage, and also allowed for true 2wd-low-range operation without hurting the hubs, etc. I recall many threads on 2nd gens having this mod to aid backing heavy trailers without over revving the engines or over heating the transmissions. I am actually looking for those threads when I cam across your question...