Problems with 4wd I need help with

[Adam Drabek]

I have a 2009 ram 1500 5.7 hemi, when I put it into 4wd I get a vibrating, pulsating feel almost what feels like brakes grabbing and releasing quickly. When I take it out of 4wd into 2wd if I'm driving along it takes a while but there is a loud clunk that feels like maybe the brake hitting real fast once then it is fine. It will only do it to me when switching to 4wd. I just replaced the 2 rear abs speed sensors thinking it was maybe that. Any help would be greatly appreciated.

 

[CVX20]

Probably your frt axle.You really need to get right off of the throttle for a sec or two to let it connect and dis-connect.If you keep the power on there is so much binding between the inner and outer axle it can't unhook properly but when it does it will clunk.You'll do some expensive damage if this persists.

 

[Adam Drabek]

No it does it in town with stop signs and everything. Before it would do something where the esp,abs,parking, and another light would come on and if I kept driving it would do that same clunk, feels almost as if the rear passenger brake hits on fast and hard them the lights would go back off all while in 2wd in the summer. I read it had something to do with abs so I changed those sensors in the rear.

 

[NJMOPAR]

Check/clean the electrical connector at the transfer case.

 

[Daw14]

Maybe things need greased up .

 

[62Blazer]

If it only does it when you shift into 4wd it shouldn't have anything to do with the rear axle. From the rear driveshaft back absolutely nothing changes between 2wd and 4wd. There is something wrong between the transfer case and front tires.....I know, there are quite a few parts that could have issues. I would check for play/movement in the front driveshaft (transfer case to front axle) and then the front CV shafts on both sides. One of those items would be my first suspicion.

 

[Neil Derryberry]

you're in 4wd on pavement?

 

[62Blazer]

you're in 4wd on pavement?

Good question......if you are locking it into 4wd and turning on pavement you will definitely get some bucking and binding going on. However if you are just running in a straight line, and assuming the front and rear tires match, you shouldn't have any significant issues.

 

[Adam Drabek]

No when the road is snow covered. Prior to this I had problems where the abs light, esp, park assist, and I think one other system would light up while driving and then after a while they would go back to normal after this same clunk (feels just like the rear I think right brake hits hard real fast). That happened to it while in 2wd and when I tried figuring it out someone said possibly a bad speed sensor, so I changed the 2 rear ones. When it does this right now like I described, when in 4wd it almost feels like it's working hard fighting the brakes doing a fast pulsating feeling. I can replicate it by putting it in 4wd.

 

[jws123]

No when the road is snow covered. Prior to this I had problems where the abs light, esp, park assist, and I think one other system would light up while driving and then after a while they would go back to normal after this same clunk (feels just like the rear I think right brake hits hard real fast). That happened to it while in 2wd and when I tried figuring it out someone said possibly a bad speed sensor, so I changed the 2 rear ones. When it does this right now like I described, when in 4wd it almost feels like it's working hard fighting the brakes doing a fast pulsating feeling. I can replicate it by putting it in 4wd.

I would have someone hook it up to a good scanner not a cheap $30 or autozone scanner see if it has any abs codes ect that dont set off the engine light ect.

 

[62Blazer]

Does this noise/issue only occur when you use the brakes? From what you are describing it sounds like possibly the ABS activating, but that should only occur when you are using the brakes. Go out to a gravel road (or dirt, snow, etc...) and hit the brakes hard as it should activate the ABS and will cause all types of weird noises and the system is basically pulsing the brakes. The ABS, ESP, etc... warning light coming on also leads me to believe it is related to this system. I have seen a bad wheel speed sensor cause the ABS to activate for no reason as the sensor will read zero so the system thinks the tire is locking up/sliding and will activate the ABS even though the wheel is actually still turning. There are also several other things that could cause a similar issue from loose connectors, partially sorted or broken wires, bad hub bearings (tone ring that sensor reads is wobbling or can't be read sometimes), etc....

With that said I absolutely hate it when somebody tells you to randomly start replacing parts with zero diagnostics. That's like blind folding someone, spinning them around in a circle, then telling them to start throwing darts and hope you hit the bullseye..........

 

[Adam Drabek]

I have an autel maxidas I'll hook it up and see. I'm not real proficient at using that maxidas Just thought maybe someone had had this issue and figured it out. The abs is working because if I come to a stop sign and it's icy I feel it kicking in.