stupid noise question

[capt den]

i recently asked a stupid cooling question and got a smart answer that helped with the problem so, here goes. within the last 2 months i have been hearing a noise which as it gets louder it sounds like a whining/grinding noise but kind of smooth and not extremely loud. wierd thing is it goes away when i step on the brakes. i am thinking bearings. i recently did the front brakes and greased the bearings there. i could replace them as that is an easy place to start. the rear is full of oil, no leaks. i have pushed grease into the holes on the axle, but not sure if they are not the problem anyway. maybe someone here is familiar with this noise/problem. i think replacing the rear bearings is beyond my skill set, but i am usually willing to learn new things. i will start with the front bearings as i want to at least check if everything is tightened up as they should be. why would the noise go away when the brakes are applied? the answer to that may well be the answer to the problem. i am afraid to drive the car now. i have no other shaking or vibration issues. thanks for any advice.   capt den

[soth122003]

Jack up the front end and spin the tires, listen for any unusual sounds. grab the tire at the 3 and 9 o'clock positions, move the tire in and out with out turning the tire to check the bearing play. (you can also check the ball joints this way too). You can also do this for the back tires as well. Also with the back wheel bearings, only the inner bearings are lubed with the oil/grease fittings. The outer bearings have to be done by hand.  If everything seems ok try a test drive as follows.

 

Try taking the car on a 5 mile drive with light braking applications and check the hub tempature. if one is hotter than the others change both bearings and both sides pass and driver.

 

Joe Lee

[Los_Control]

I think @soth122003is correct in getting the wheels off the ground for further inspection.

I think when you apply the brakes it goes away is a clue it is in the front .... The drums are flip flopping around from loose bearings .... apply brakes & it put things back in alignment.

 

Drive train noises can be tough to track down, the noise can just as easily be a u-joint going bad .... the noise seems to transfer throughout the drive train & difficult to pinpoint origin without getting the wheels off the ground ..... I would try for all 4 at the same time if possible .... And possibly run it in gear while it is off the ground.

 

I made a mistake recently diagnosing a noise .... it was a more serious clank clunk noise. We drove it on a 2 hour freeway trip the day before & parked it.

Was no issues. Drove to the hardware store the next morning ... made it to the stop sign  & limped it home two blocks.

I swore it was the rear end .... I knew the noise was the rear end!

 

I drained the oil/removed the cover on my daily driver cheby ...... inspected everything, no problems .... So I pulled the axles out and checked the bearings .... no problems.

Now I'm getting worried it might be a issue with the NV3500 transmission.

For giggles I jack up the front. I saw the left front wheel lean since the outer wheel bearing disintegrated. ..... Sigh of relief, I instantly knew where the problem was.

 

I'm just saying, if I put all 4 wheels off the ground I would have found the problem instantly. .... Instead I spent 2 days concentrated in one area & I was wrong.

Don't be Fred!

 

On a side note, my DD truck has well over 400k miles on it, I found out my rear end has been rebuilt, 3:08 gears, no metal shavings & perfect condition. ???

[kencombs]

Not to be a smart a**, but since this apparently started after doing the front brakes, I'd suggest checking the bearing adjustment.  Rule I follow:  always check the most recent thing changed before looking other places.

[rcl700]

On my daily driver truck a had similar issue and noise would go away when brakes applied. Turned out to be a bad front wheel bearing. 

[capt den]

i should have time this week to look at this.  thanks for the advice.   capt den

[capt den]

soth says there are grease fittings for the inner bearings on the diff. never saw those on my 54 windsor. i have packed grease into the outer ones by hand. hope i am not missing something. i thought the inner bearings were lubed by the oil in the diff.   capt den

[Hickory]

Check for a backing plate rub also. Real common after doing some work on brakes.

[soth122003]

On the 46-54 model Plymouth Mopars there weren't fittings per se. There was a small screw plug that was removed and lubed with about 2-4 pumps of a light pressure grease gun then sealed back up with the plugs. Just check the 1946-54 manual and it states a 1/2 oz of medium fiber grease. Pg 311 of the Plymouth service manual. Check your Chrystler manual in the lubrication section.

 

Hope that helps.

Joe Lee

[Kilgore47]

21 hours ago, capt den said:

i thought the inner bearings were lubed by the oil in the diff

As soth122003 states above - the rear axel bearings are not lubricated by the oil in the dif.  They require grease just like the front wheel bearings.  But these rear axel bearings are often over looked during normal maintenance.  When I got the P15 the rear end made an awful growling noise.  The axels were pulled and the bearings fell apart when they came out.  Replacing them cured the noise.  

[capt den]

thanks for the clarification. i have put grease in the plug on the diff, so i think those bearings are fine. have not pulled the front wheels yet, waiting till after the weekend. it is mothers day AND the wifes birthday.

[soth122003]

Did you put grease in the Diff plug or the plug on the axle (about 2-3 inches from the brake backing plate on the rear axles one per side)?

 

I also know how you feel about the wife's two special days so close together. Our anniversary is on the first and mothers day 2 weeks later, and MOMMA never lets me forget about them. lol

 

Joe Lee

[keithb7]

A mechanic’s stethoscope is a handy item. Safely block up all four wheels. Leave the wheels on. Get a friend in the car. Start it. Put it in gear 2nd or 3rd at idle is just fine.

 

Your friend should be competent in the workings of an automobile. Brake, clutch park brake etc. you cannot have someone behind the wheel that might panic.
 

You lay under the back of the car and poke the stethoscope probe at both outer wheel bearings and rear axle pinion bearings. Hear anything odd? 
 

For extra safety use solid blocks of wood to block up the vehicle under the frame. Suspension hanging. Also have the front bumper right up against a firm wall. A brick or cement wall is nice. The car is not going anywhere while you are under it.
 

I have done this and lived to tell the story. I found a bad wheel bearing. 

Edited May 12, 2023 by keithb7

[Dodgeb4ya]

Don't have loose clothing to get pulled in by the tire or driveline while the wheels are turning!?

[keithb7]

Great point! I was bare armed and in cargo shorts.

 

Extreme caution is required. Someone might see your white pasty hairy legs in shorts!

[OUTFXD]

On 5/7/2023 at 11:44 AM, capt den said:

i recently asked a stupid cooling question

Now now,  The preferred nomenclature is "Special" cooling question!

Edited May 13, 2023 by OUTFXD

[Young Ed]

On 5/12/2023 at 2:17 PM, soth122003 said:

Did you put grease in the Diff plug or the plug on the axle (about 2-3 inches from the brake backing plate on the rear axles one per side)?

 

I also know how you feel about the wife's two special days so close together. Our anniversary is on the first and mothers day 2 weeks later, and MOMMA never lets me forget about them. lol

 

Joe Lee

Got you beat this year. Anniversary is today so we are back to back!