Hi All,

I have a '98 1500 4x4. It shifts into 4wd fairly well but the light stays on for quite a while after shifting back to 2wd.

I checked the vacuum ports at the front axle. In 4wd there is vacuum to the left port and none to the right. In 2wd there is no vacuum to either. Also there is no clamp on the right port (from the factory that way?, I am the original owner). Is there supposed to be vacuum on the right to help disengage the axle on the '98 model year?

I jacked up the right front wheel to check the system. Even when the 4wd light goes off, turning the right wheel still turns the front drive shaft, so I am not sure if it is fully disengaging.

Maybe I should just install a Posi-lock.

Thanks,
Barry

 

hmm, usually my technique for shifting out of 4x4 is if im not on a main road, ill switch from 4x4hi to 2hi and roll a lil bit forward like 50 feet and then put it in reverse and give it a lil gas to make sure its out, usually it goes out but what pisses me off is that sometimes it stays on for a lil while after i take it out and then it goes clunk when iit comes out.. hopefully its normal eh? lol.. as for your truck i think i think ur turning the dshaft still because its where the ring gear is in the front its easier to turn the whole axle that way where it disconnects is in the t-case i thought.

 

I had the same problem. Sometimes light stayed on for 30 miles. Got a posi-lock and it was worth every cent. Another way to see if you axle is still locked is with the truck on the ground see if you can spin the drive shaft. It should be easy to turn be hand if axle is disengaged. If no spin, axle is still locked.
Some techniques I used to get to pop out included driving up and off curbs, tapping axle with hammer. Posi- lock will permanently fix problem though.

 

did u posi lock front and rear? so basicly a new front dif was solve the problem?

 

No, the Posi-Lok is to replace the vacuum activated CAD.
http://www.windrockoffroad.com/part_...ubCategory=142
Your actuator is going bad. I had all those problems above till I replaced it with the Posi-Lok.

 

OK, I have sorted it out.

There was a crack in the vacuum line to the right port of the actuator (the one that unlocks the axle). So, I was not fully disengaging when in 2wd. I had essentially no vacuum to the actuator on this side. The vacuum switch on the transfer case was also shot, basically gummed up and frozen in position.

I fixed the plastic vacuum line with some electrical shrink tubing. I got a new vacuum switch at the dealer for about $21 (same price as NAPA). So the system is working perfectly now. The 4wd light goes on and off very quickly now when you shift the transfer case. When I jack up the front right wheel in 2wd, it spins freely without moving the front axle. In 4wd the wheel is locked.

I think my front axle has been partially engaged for a long time!

The Posi-Lok sounds great, but I think I am OK for now.

Thanks for the help,
Barry

 

got a few problem i believe regaurding my 4x4 on my 98 ram 1500 5.2 with automatic tranny.
i have now dash lights fore some reason when i just replaced the indacator lamp switch mounted on the front axel. also i replaced all the vaccum lines that run from the shift motor to the tcase vaccum switch also replace the the tcase vaccum switch and still not getting lock like i should but when i try to spin the axel i cant with it engaged or when i jack up truck to try and spin passanger tire i cant so it passed all the land test in my driveway but when i go to use it i get nothing from the front tires. i thought of getting the posi lock to replace it all but dont have the money for that right now just wanna get it fixed so i can use 4x4 when i need it any info would greatly be apriciated