Engine/Transmission (1998.5 - 2002) 4 wheel drive

[DISPATCH]

my 4 wheel drive light does not come on it takes a while to engage. some times it grinds after you pull back on the lever any ideas??

 

[y-knot]

Some times they do take a minuet or so, mine goes right in say 20 seconds max. The grinding can be helped some by letting off the "fuel" peddle and engaging the transfer case in one swift movement. Also you should be doing less then 60 MPH. If you are going into 4Low, you must first come to a stop, then engage. A 2Wlow kit, would be a wise investment. Bob V's is the best in my opinion and only cost about 80 bucks.

 

[DISPATCH]

i let off the fuel peddle and pull back on the lever wait a little bit then go some times it will still click or grind. the light never comes on, could it be just a bad bulb or what where do i get the 2wlow kit?

 

[y-knot]

First you need to varify what is happening up front. The front axle is held in and out of engagement by a vacuum actuator located on the front axle,passenger side back. You will find two vacuum lines going to the actuator, one should always have vacuum while the engine is running. Also, right above and a little right is a switch with two wires coming out of it. This is what tells you if the axle is engaged, this is what turns the light on in the dash. You may be having a had time engaging the transfer case because the axle is already engaged. It is controlled by vacuum, and suppose to have the transfer case engage, then the axle follows. You need to verify that you have vacuum to the front axle. Then if you do not, you will have to trace out the lines and see why not. From the vacuum pump on the engine (drivers side front low)a vac line goes back to the firewall, tees with one to the cruse control and the other tees again. One now goes inside to work the HVAC system, and the other goes down the firewall to the top of the transfer case. There it connects to a 4-way block. From the block two line go to the front axle, and terminate ate the CAD (central axle disconnect), or vacuum actuator. See what you have and get back with me, Good luck.

 

[JSandusky]

This brings up some interesting points and questions about our 4x4 truck and their transfer case operation.



Let me start by saying I don't have an owners manual for my truck, it didn't come with one. So I'm not sure what Dodge say's is the proper way to shift MY truck into and out of 4 wheel drive.



I know the 98. 5 4x4 uses a sliding front axle locking system that is actuated using a vacum syloniod. What this accomplishes is it unlocks the front axles so that the front differential and drive shaft do NOT move when in 2 wheel drive.



Some of you say it's fine to shift our transfer cases while moving. I don't see how this could be a good thing to do, since the front driveline is settin still and not spinning when you go to engage it while driving down the road. This would in my mind certainly cause the gear grinding lots describe and I personally get EVERYTIME I try to engage 4hi while moving. However shifting from 4hi to 2hi on the fly might be OK, since everything is spinning at the same speed, as long as the load is removed before shifting, as others have described doing.



I read somewhere that dodge did away with the sliding "locking" front differintial, switching to a full time system, in which the front drive line is always spinning at the same speed as the back. In that configuration, I could see shifting from 2H to 4H being smooth and ok when not under load.



So I have a couple of questions:

1. What year did Dodge switch to the full time 4x4 system instead of the sliding "locking" system the 98. 5 has?

2. What is the procedure in the Dodge owners manual for shifting into 4HI on a 98. 5 Dodge 3500 4X4?

3. What is the procedure in the Dodge owners manual for shifting into 4HI on a full time 4x4 truck, one of the newer ones that the front driveline is always spinning?



I think the answers to these questions will help clear up some of the meths on the transfer case shifting, at least it will for me.



Thanks,

James

 

[rfcom]

I can only answer #3.

My manual states that it is safe to shift from 2H to 4H and back at speeds up to 80 kph (50 mph) by simply depressing the clutch and move the lever. The front and back wheels must be going the same speed, ie. , no slipping. Going from 2H to 4L, you must be going less than 5 kph, put the transmission in neutral and press in the clutch. Again, no slipping. Move the lever smartly from one position to another, do not stop at neutral. I can verify this works as I've never heard a clunk or crunch while shifting the T-case. HTH



Jim



Edit: Forgot to add that mine is a 2002. 5 with the full time spinning axles.

 

[RowJ]

James: Dodge switched to full time 4 wheel drive (front axle engaged) in early 2002 (January, I believe). Mine is built in Oct, 2001 and does not have it.



Don't believe the process for shifting on the fly changed any after they made the full time engeged models.





Blue Beast: With an Auto, I find it engages best, on the fly if I back off throttle and go for smooth, all the way, shift. Light (& engagement) do not happen until I get back on throttle a little.

I stopped getting any grinding when I decided to stay at 40 mph or less for engagement of 4X4.

Can only get smooth 4X4 low shift if I'm neutral on both shifters and rolling about 1 or 2 mph forward before I engage transfer case in 4low. Manual says something about this method also.

 

[Steve St.Laurent]

JSandusky - your confusion comes from a misunderstanding on how the system works. All the the sliding disconnect on the passenger side axle does is disconnect the axles from each other thereby opening up the differential and not spinning the front driveshaft. The axles themselves are spinning at the same speed as the rears. The only way to disconnect them completely is to have hubs that you can unlock - which we don't. So the only thing you are spinning up when shifting into 4hi is the front driveshaft and center of the diff. You can change from 2hi to 4hi or back at up to 60 mph. You do need to move the lever with authority - don't slowly pull it or you will get grinding. As the front vacuum slides into place you may get a slight bang as everything lines up but the system is designed for it. Now if you are slipping the rears when you engage it you will get a much louder bang and the more diameter difference between your front and rear tires the louder the bang will be as well.

 

[Hohn]

The smoother shifting is one nice feature of not having the CAD. More than once have I shifted back and forth a lot with no banging. The only time i get a little grind is going into 4-lo.



My truck was built in July '02, so it's about the last of the breed...



Justin

 

[Duluth Diesel]

My '02 has the live front axle as well. Glad to have it. When I pull that lever, I am in 4x4 without question. I just change the front diff when I change the rear diff fluid since the front is spinning all the time.

 

[Sootscooter]

y-knot, can you explain the 2wl kit you mentioned?

 

[Bodybomber]

The problem with the live front axle in my opinion is that you cant do 2low and all that crap up there is spinning all the time eating fuel.

 

[Lazy-Boy]

Got dumb question.

What's the equivalent gear ratio difference between 4HI and 4LO?



I've never owned a 4WD but, in recent days I sure could've used it.

This HI/LO operation of 4WD is the only thing I'm not really sure about. Does it still exist when you go to reverse as well?

 

[Turbo Tim 1]

The ratio in high range is 1:1 as would be expected but in low range it is 2. 72:1 as can be seen here.



Transfer Case



And to answer your question, Yes it does work in reverse. Basically the transfer case is between your transmission and axles and divides the power to the front and rear.



I can tell you that in 4 LO 1st gear it's pretty hard to make the speedometer move

 

[Lazy-Boy]

Thanks Tim.

Yea I definitely could've used that a few weeks ago.

Heck - if there was a way to temporarily turn off LSD then I would have probably been OK.



Nothing worse then having plenty of power and it will only spin one wheel. I followed all the LSD standard ways to get it to spin the other tire. But it just wasn't gonna happen.

Man I was mad!



Time for 4x4.