mr T

i got a really annoying rubbing or grinding in my fron axle area...feels like its on my drivers side but only cause im sitting there...it happens when im driving in a straight line. it gets faster as the wheels get faster naturally ...the axle is straight...i never hit anything....i dont tow...and nothing is leaking......havent checked anything yet but will this weekend...what to look for? does this sound common to anyone?...tires are stock 245/75/16

mr T

ok lil update...ive never changed the fluid or check the fluid in the transfer case...could that be a big factor??...after that ive kinda narrowed it down going through some troubleshooting stuff i have at home...i think it could be the front U-joint...but how to check for damage or wear?? ...anyone have pointers? and then how hard is it to replace? approx cost in parts??

phox_mulder

1995 CTD 2500 4x4 ...282 000 km

Please tell me you haven't owned the truck since it was new.


phox

mr T

nope .. get real...got it 20 000kms ago

good one phox

phox_mulder

Had to check.

Some people don't quite get how things work.

I'd be leaning towards wheel bearings, or maybe a stuck brake caliper.


phox

mr T

those are the exact 2 things my dad was thinking...too funny...ok now to access the wheel bearings i gotta....help a bro out...as for the U joint what can i do to rule out the u joint... lift the front turn the wheels and see if the U joint is loose ?
also this winter when i had it in 4H it would grind abnormally as well

Hemi Cat

The best place to start is by jacking up the front axle and rotate the tires by hand and listen for the grinding noise. Then that is the wheel you start with.I doubt it is a u-joint. Your description doesn't fit u-joints. Probably brake pads or wheel bearing. Sometimes I encounter a stone caught in the pad causing noise. But a complete inspection is in order for your truck. Good luck

mr T

umm dumb question phox ...whn im driving in 2 wheel drive mode is my front driveshaft spinning?? or is my front axle simply freewheelin and the front driveshaft only spins when i have it in 4 wheel drive?...never actually thought about that...ya know?

Hemi Cat

The axle shafts spin all the time and there is a coupling inside the front axle that engages the axle to the diff. When in 2 wheel drive the front drive shaft just sits there, you can grab it and turn it by hand.

mr T

ok then it cant be the U joint....thanx hemi cat...

mr T

i was having trouble this winter with vibration while in 4H mode but it would always dissapear once back to 2H...but i also had trouble having id disconnect out of 4H...it would take awhile and then "pop" out so i started putting it in neutral switchign to 2H and then back to drive and that seemed to fix it

now im gettign a very similar vibration....could it be im simply not fully disconnected out of 4H? how can i crawl under the truck and make sure i am in 2H and nothign in between?

tjohnson

You really need to get under there and check out your 4WD vacuum actuator. It is very simple to do, it is located on the passenger side of the front axle and is bolted on with 4 bolts. It has two vacuum lines, one red and one black coming from the vacuum switch on the transfer case, a vent hose, and an electrical connector to a switch that operates the yellow 4X4 light in the cab.

Disconnect the two vacuum lines and the electrical connection. Get a drain pan underneath the actuator, you're going to loose a little gear oil. Take out those 4 bolts, remove gently as to not tear up the cork gasket behind it.

You should simply see a fork that slips over a collar that slides back and forth over the two axles when engaging and disengaging the truck in 4WD. Look to see that the ends of your fork have some tiny plastic wear plates clipped to the ends. If they are gone that might be laying in the gear oil at the bottom of the actuator housing, dig them out before they make their way to a wheel bearing and cause BIGGER problems.

Slide the fork back and forth on the vacuum motor shaft, it should slide easily with only gentle pressure, you should also hear and feel air shooting out each vacuum port on the vacuum motor as the fork is moved.

You can now reconnect the vacuum lines to the actuator and get in the cab, start up your truck and make sure the fork is operating properly with the shifter.

These are actually very reliable systems when properly maintained. I have just went through the entire system on my 1994 and it works like a new one again.

The vacuum motors are REALLY expensive and are a dealer only item, hope you don't need one. Word of warning....these vacuum motors DO NOT screw out, if you put a wrench on it you will bust off the small ear on the cast actuator housing that keeps it from rotating, you have to knock off the retainer clips on the motor shaft and it will slide out. Salvage yard is best bet if you do need an actuator, these actuators are used on lots of trucks for several years.

The wear plates for the shifter fork are part of kit that contains the cork gasket and 4 bolts, $11 from your Dodge dealer. Let me know and I can provide you with the part #.

phox_mulder

Got caught sleeping.

Yes, everything in the above post.

As to the vibration in 4 wheel drive, check the front driveshaft CV joint, the joint at the transfer case.


phox

tool

Mr T.

It could still be a u-joint, the axle u-joints are spinning all the time whether it is 2 wheel or 4 wheel. (although not under any load in 2 wd)

I'd still be leaning more towrads the wheel bearing/hub assembly.

Hopefully it's a dragging brake pad. As stated, jack it up and spin the wheels by hand, listen carefully. Inspect your rotors for signs of something dragging.

mr T

k day #2 of this vibration/grinding...it has NOT gotten worse...first off i checked the transfer case fluid and it was down...i added fluid.....next i liftend the truck and spun the wheels slow and fast and had my ear right at it and there was never a sound or resistance of any sort....went under the truck while it was off and just played with the front driveshaft...i can wiggle it very slightly....like 3 mm up n down...bottom line i can make it wiggle...its not rock solid...is it supposed to be?.....checked the front differential fluid ...the level is right on but its very crusty fluid...whats it supposed to look like? mine looks like grey mud!....need to gear lubricant and change that?

another thing...im trying to pin point the vibration...its under my brake pedal!! like right under i can firmly press my foot to the floor and feel the vibration strongest in that area

ps the grinding gets a lil wore as rpms go up and can REALLY be felt as i coast to a red light
oh yeah thats coasting WITHOUT applying brakes