Front axle Noise

[TRedwine]

I have a 03 3500 4x4 SRW. Have a noise coming from front ,thaught it was a wheel brg. going bad . Changed it , noise still there. Just changed the fluid about 2500 miles ago. Noise sounds like big mud tire humming. Also just had new tires put on , street tread . Any sug. where to start.



Thanks,

 

[rbattelle]

Have you checked the front driveshaft - particularly the centering ball in the double cardan? In 2003 it didn't have a grease fitting, so in order to lubricate it you've got to pump grease in between the rubber seal and the ball.

If you've already pulled the front driveshaft and the noise didn't disappear, check both front universal joints. And check the bearing you didn't replace.

If all that checks out, then my guess would be your pinion angle is off, possibly due to a loose pinion nut.

I suppose it could also be a differential bearing. But start small and work your way up.

Ryan

 

[ENafziger]

I have a 03 3500 4x4 SRW. Have a noise coming from front ,thaught it was a wheel brg. going bad . Changed it , noise still there. Just changed the fluid about 2500 miles ago. Noise sounds like big mud tire humming. Also just had new tires put on , street tread . Any sug. where to start.

I have the EXACT same noise! It started a couple months ago at about 44k miles on my 06 3500 4x4 SRW. The "big mud tire humming" description is pretty accurate. Mine is particularly bad between 65 to 70 mph. It's almost so loud that it's hard to talk to someone in the cab.

Mine seems to be coming from the front driver's side. I have the greasable front drive shaft, and have greased it thoroughly. I may remove the driveshaft for a few days and see it that changes anything.

Any other suggestions?

--Eric

 

[TRedwine]

I think I am going to pull the center cover on the axle and take a look at the gears. See if there is anything loose. I checked the u-joints and they were both good. Talked to a guy at the dealer and he said there were special tools to align

the gears so it must be adjustable. Mine may be out of adjustment. My sound actualy gets a little quieter at 65-75 mph, can hear it good at 25 -50 mph.

 

[TRedwine]

Ryan,



Are there special tools for aligning the gears in the front axle?

I have checked all that you told me to and no luck. I think it might be the bearing on the pass. side of the axle . If it is, can this bearing be replaced or do I have to get new chunk.



Thanks Thomas

 

[rbattelle]

Are there special tools for aligning the gears in the front axle?

--In case you need to remove the pinion--
The pinion shaft has an inner and an outer bearing on it, both of which are pressed on. So you have to drive out the pinion from the differential case (which removes the outer bearing at the same time), then use a puller long enough to reach the bearing from the end of the pinion shaft to get the inner bearing off.

Pinion depth is set by a simple shim during reassembly (before the inner bearing is pressed back onto the pinion shaft). The manual doesn't say whether shims of different thickness are used - it simply says "install pinion depth shim on the pinion gear shaft". I guess maybe pinion depth needs no adjustment, since doing so would be a huge PITA (you'd need a new crush sleeve and have to remove/install both the bearings every time you wanted to try a new shim thickness).

When it's time to reinstall the pinion nut, you simply tighten it until you get a drag of 15-20 in*lb on a dial-type torque wrench.

There is NO mention of adjusting the pinion depth! I'd like to think that's because you don't need to if you're using an OEM ring and pinion, but I don't know for sure.

There specialty pullers which can be improvised using some iron pipe. There's a "special wrench" that holds the pinion flange while you remove or install the pinion nut, but I think that would also be easily improvised.

--This section for differential only--
To align the differential after a bearing replacement, there's a whole procedure of adjustment. I'm attaching a picture of the spanner to this post, along with a picture of the bearing adjustors where the spanner is used. That special spanner looks pretty simple - you might consider making one rather than buying it.

You need to check backlash too, so a dial indicator might be necessary (although the procedure in the service manual shows how to do it without any dial indicator).

It's not a difficult procedure, but you will need a service manual to do it. Lots of steps.

Ryan

[Images courtesy the 2003 factory service manual]

 

[Bob4x4]

Had one in the shop this week with a noise similiar to what you describe it ended up being a bent front housing,of course the customer said he never had it off road much less any air under it :-laf



Bob