Engine/Transmission (1998.5 - 2002) 4WD Problem

[JFitzgerald]

Something is wrong with my truck's 4WD system. It engages and the light comes on on the dash. I can feel that the front axle is pulling some, and I can feel the normal binding in a turn. It's fine until I get on the throttle, even a little. It sounds/feels like it is not fully engaged and gears are slipping (clunk-clunk). Driveshafts and u-joints are in good shape. It does this in 4HI or 4LO. I'm very familiar with older 4WD's, but not this new axle disconnect system, which is where I suspect the problem is. I know it could also be the transfer case, but doesn't "seem" to be.



What is used to actutate/engage the front axle? I know GM used a goofy gas/thermal system and upgraded it with something else later. Not sure about Dodge.



Is it possible that the system is not fully engaging?



What is involved in tearing this newer Dana 60 down compared to the older locking hub style? Any special tools needed?

 

[szumilas]

similar problem

Your front end is engaged by a vacuum pod on the front axle with a sliding fork and collar internally. The vacuum pod is on the pasenger side of the axle. I would check for a vacuum leak at the pod first. Pull off the vac lines at the pod and check for vac with the engine running. You should only have vac on one line. Now shift your t case into 4wd. The vac should change from one vac line to the other. If that is good then the collar may be damaged or the actuator pod may have an internal leak. The actuator unbolts from the eaxle with 4 bolts. You can remove the actuator and test it with the vac lines hooked up and see if the fork moves. I had asimilar problem with my '00 2500. I had a bad connection on one of the vac lines and the actuator was leaking enough to not engage the collar all the way(grinding noise).







Good luck.

 

[JTeague]

Another place to check is the shoes on the shift fork on the actuator. After you remove the 4 bolts, vent hose, vaccuum supply lines, and unplug the 4x4 switch, Inspect the plastic shoes on the fork for wear (sometimes they are totally gone) and forwear on the fork itself. If they appear ok, move the shift fork from side to side while checking for binding. I have seen the shaft of the actuator bend causing the fork to not travel freely.



Jason

 

[JFitzgerald]

Thanks for the input, guys. I'll check those things out. I do have a vacuum gauge to test the vac signals. Any info on tearing into that axle if I need to?

 

[IC Smoke]

If you want to get rid of the vaccum style on the front end check out "4x4 posi-lok" out of Coldwater, MI (Planet Powersports has them) and its a manual system that engauges your 4wd. We just installed one on our 88 chevy 1ton 4x4 since the electronic actuator goes bad in it about once a year. 150 for a actuator or 155. 50 for the manual style.



Ian



http://www.4x4posi-lok.com/



call for a better price-

http://planet-powersports.com/

 

[JFitzgerald]

I checked out the shift fork, actuator and everything up front. The actuator shifts with a firm clunk while hanging loose with the engine running. Splines look good and the collar slides across them just fine. Shift fork shoes look good - they look like stainless steel on mine. Apparently it's the transfer case. Don't have the time to dig into this project, so a mechanic friend of mine is going to look at it this week. I did find the transfer case was a quart low, but refilling it didn't make any difference. Now it's not wanting to pull into 4 high most of the time.

 

[JFitzgerald]

Just thought I'd report back. I picked up the truck today. He replaced a bent shift fork and shoes, and the back half of the case because he found a hairline crack which was causing the leak. He said the gears, bearings and everything inside looked perfect. He suspected the overhanging weight of the GV overdrive was affecting the shift linkage adjustment too. It's working good now, just in time for more snow.