4wd Question

[Braeden Clark]

So I was crawling under my new truck today and decided to spin the front driveshaft with all 4 tires on the ground in 2wd. The front driveshaft spun freely. Is that normal? I then put the t case in 4 hi and it now doesn't spin freely? Normal right?

After all this I decided to go up a wet hill in my truck to test 4wd. Never seemed to work? What is my problem? I'm kinda worried rn. The 4wd light never came on in my truck either.

 

[Braeden Clark]

So I was crawling under my new truck today and decided to spin the front driveshaft with all 4 tires on the ground in 2wd. The front driveshaft spun freely. Is that normal? I then put the t case in 4 hi and it now doesn't spin freely? Normal right?

After all this I decided to go up a wet hill in my truck to test 4wd. Never seemed to work? What is my problem? I'm kinda worried rn. The 4wd light never came on in my truck either.

As a side note my cruise and hvac both seem to work.

 

[392DevilDog]

Ok. What year and model is your truck.

Had to turn my phone sideways but I see this is posted in 94 to 02.

So the issue is the front CAD vacuum bulb. It bas to move the shift fork to display the 4wd light.

This is why when you locked 4wd you couldn't move the driveshaft but you still did not have 4wd.

I put a posi-loc in mine but then eventually just did the e clip flip and permanently locked my CAD.

If the bulb isnt rusted you may have just knocked a vacuum line off. There are 2 at the bulb and the go to the transfer case and then up to your engine.

Since cruise is working...i am leaning towards the bulb.

It will be on the passenger side of the front axle.

 

[392DevilDog]

CAD center axle disconnect.

I forgot one thing. If the vacuum lines are good...and the vacuum bulb is good. You could have a broken shift fork.

All easily repairable and should still be readily available for purchase

 

[Braeden Clark]

CAD center axle disconnect.

I forgot one thing. If the vacuum lines are good...and the vacuum bulb is good. You could have a broken shift fork.

All easily repairable and should still be readily available for purchase

Is the any issue with the e clip flip thing? Will it damage the axles or differential? Also, if I did that would I need to disconnect the vacuum lines or could i leave them connected?

 

[392DevilDog]

There is no issue. You can leave the vacuum lines.

You should cap them though.

You just need to take the four bolts off and remove cover. Then remove the e clips from the rod slide the fork over and reinstall the e clips

I am almost out of data so can not upload a pic. But you can do a google search and see what I am talking about

 

[Braeden Clark]

There is no issue. You can leave the vacuum lines.

You should cap them though.

You just need to take the four bolts off and remove cover. Then remove the e clips from the rod slide the fork over and reinstall the e clips

I am almost out of data so can not upload a pic. But you can do a google search and see what I am talking about

I know exactly what you are talking about. I just don't want it to wear anything quicker. If I'm not mistaken, this would make the setup basically the same as what my Jeep runs. Only the t case controls 4wd. No vacuum lines

 

[392DevilDog]

Correct

The CAD was used to gain an MPG or two.

I have had the CAD locked on my 99 for 5 ish years now. No issues. In 2003 they ditched the CAD and then it came back again in 2013...to get a MPG or 2.

Anything could possibly happen...but very low likely hood it was caused by locking the CAD.

 

[Braeden Clark]

Correct

The CAD was used to gain an MPG or two.

I have had the CAD locked on my 99 for 5 ish years now. No issues. In 2003 they ditched the CAD and then it came back again in 2013...to get a MPG or 2.

Anything could possibly happen...but very low likely hood it was caused by locking the CAD.

Update. I bought all new vacuum lines for my 4x4 system. Only $50. 4x4 engages perfectly. Only small issue is when I take it out of 4 wheel drive, the front axle stays connected sometimes. Almost like it sticks. The light on the dash says it's out of 4x4, but the front axle is still locked. It will go into 2wd most of the time if I fully turn the wheels one way and move forward or back for a few feet. Anything I can clean/ replace to fix this? Maybe the vacuum actuator?

 

[392DevilDog]

Sometimes you just got to back up a few feet.

Glad to hear it is fixed

 

[Braeden Clark]

Sometimes you just got to back up a few feet.

Glad to hear it is fixed

Tried that. Seems like it only goes out of 4wd if I fully turn the wheel and drive a few feet. Really not a big deal but is there anything I can clean to maybe make it easier?

 

[392DevilDog]

Did you take the 4 bolts off and look in at the fork and rod?

It could be slightly bent or gunked up. I suppose the vacuum bulb release shaft area could be gunked up too

 

[Braeden Clark]

Did you take the 4 bolts off and look in at the fork and rod?

It could be slightly bent or gunked up. I suppose the vacuum bulb release shaft area could be gunked up too

Yea that's what I may end up doing. Right now it works well enough. It's just strange to me because the sensor thinks it's disconnected but not. Maybe like you said something is just a little gunked up and needs cleaned so it won't allow it to slide as easily. Hopefully that's it.