fury fan
Senior Member
I generally am giving out thoughts and ideas, but now it's my turn to ask for help.
I'm trying to diagnose some car noise, I had my conclusion made (blaming the axle gears) but I started taking things apart and now I'm unsure.
Car: 68 Plymouth Fury, lots of miles but many things have been rebuilt. Was a well-maintained/very reliable driver in past years but hasn't gotten more than 1000 miles in the last 5-7 years. (it is still very reliable, though)
It has a bit of noise that I have assumed is the rearend gears. It is a slappy-growl that happens as soon as the car starts moving, and doesn't change with load, nor accel/coasting. It's pretty linear with road speed. And it's quite noticeable.
The gears are 3.55SG I got from a buddy many years ago, he said one of teh bearings had a roller fall out but otherwise OK. (didn't notice any damage on the gears)
I took the gears to a shop to get the bearings replaced and a new seal. Was told would take about a week, 6-ish weeks later I begged them to get it done so they finally did. (a reputable shop, and I carried the gearset in, was not installed in the car)
I didn't install the gears right away, they sat for awhile (past any warranty or complaint period)
Buddy and I installed a slightly-narrower axle in my car (from a 66-67 B-body, IIRC), and I believe this is when the gears probably went in - but I don't remember. (I've had this car 25 years. Regardless, the gears sat for awhile).
The axle shaft bearings (from that used narrower axle) were surely cleaned/greased at that time, likely new inner shaft seals also (the ones in the housing).
This noise has not always been there, I don't remember when it started but was either when the narrower axle/shafts were installed, or when the gears were installed.
But I've always suspected these gears as the culprit. I pestered the shop to finish the job and I wondered if maybe they just gave it a new seal and a paintjob to make me go away? (again, my buddy said a bearing was missing a roller)
Sidebar:
I sometimes have a very squeaky brake when driving forward and hitting the brake, it goes away after 20 feet or so. If I drive the car 1/week it doesn't happen. Only if it sits for a month or longer.
Tonight I pulled the rear wheels to check the brakes and begin a gear swap.
Passenger drum came off easily, the driver's required a little nudging with a small prybar (but not unusual).
The passenger side backing plate has some wetness from the axleshaft and lower. Teh wheel cylinders have the type of boots that are very stiff, so don't want to pop off to see if a leak, but it is pretty dry south of the whl cyl.
There is a tiny bit of wetness that starts just south of the axleshaft retainer flange.
I will presume this to be the squeaky-brake culprit. (until better evidence comes along, anyway)
Driverside brake looks A1, just some mild dust on the 'new' springs installed at the last brake job.
So:
I turn the passenger axleshaft and expect to hear lots of awful noise. However - it's quieter than any axle I can remember and it felt nice.
Both axles are turning the same direction, but it's kinda easy to turn them the forward direction.
Turning them rearward is significantly more difficult (and they also turn the same direction). IS THIS NORMAL???
The driveshaft is turning during all of this. I reached under to wiggle at the rear U-joint to see if any significant wear but it seems tight. (I replaced those U-joints years ago, and would guess to have 75k on them, so are due for inspection)
I put a screwdriver-stethoscope on the axleshaft retainer plate and rotated the shaft and heard minimal noise. It maybe sounded a little dry, but at this point I'm looking for bad, so the brain will invent it if necessary.
Driverside bearing sounded quieter and almost seemed like I could hear the other bearing thru the housing also.
Regardless, I didn't find anything that would seem to cause such an immediate noticeable noise.
Next steps are:
Remove the driveshaft and re-spin the axle.
Check the U-joints (they are due!)
Then remove axle shafts and feel the bearings.
But wanted some thoughts from you guys as well.
Video of spinning the axle:
Starts out showing forward rotation, via twisting the axle flange.
18 secs - reversing direction, which is significantly harder to turn.
30 secs - putting the drum on the axle studs for more leverage.
45 sec - ill-fated attempt with bungee cord to show other axle is rotating the same direction.
58 secs - installed tire to show direction.
Pic of under the wheel cylinder:
I'm trying to diagnose some car noise, I had my conclusion made (blaming the axle gears) but I started taking things apart and now I'm unsure.
Car: 68 Plymouth Fury, lots of miles but many things have been rebuilt. Was a well-maintained/very reliable driver in past years but hasn't gotten more than 1000 miles in the last 5-7 years. (it is still very reliable, though)
It has a bit of noise that I have assumed is the rearend gears. It is a slappy-growl that happens as soon as the car starts moving, and doesn't change with load, nor accel/coasting. It's pretty linear with road speed. And it's quite noticeable.
The gears are 3.55SG I got from a buddy many years ago, he said one of teh bearings had a roller fall out but otherwise OK. (didn't notice any damage on the gears)
I took the gears to a shop to get the bearings replaced and a new seal. Was told would take about a week, 6-ish weeks later I begged them to get it done so they finally did. (a reputable shop, and I carried the gearset in, was not installed in the car)
I didn't install the gears right away, they sat for awhile (past any warranty or complaint period)
Buddy and I installed a slightly-narrower axle in my car (from a 66-67 B-body, IIRC), and I believe this is when the gears probably went in - but I don't remember. (I've had this car 25 years. Regardless, the gears sat for awhile).
The axle shaft bearings (from that used narrower axle) were surely cleaned/greased at that time, likely new inner shaft seals also (the ones in the housing).
This noise has not always been there, I don't remember when it started but was either when the narrower axle/shafts were installed, or when the gears were installed.
But I've always suspected these gears as the culprit. I pestered the shop to finish the job and I wondered if maybe they just gave it a new seal and a paintjob to make me go away? (again, my buddy said a bearing was missing a roller)
Sidebar:
I sometimes have a very squeaky brake when driving forward and hitting the brake, it goes away after 20 feet or so. If I drive the car 1/week it doesn't happen. Only if it sits for a month or longer.
Tonight I pulled the rear wheels to check the brakes and begin a gear swap.
Passenger drum came off easily, the driver's required a little nudging with a small prybar (but not unusual).
The passenger side backing plate has some wetness from the axleshaft and lower. Teh wheel cylinders have the type of boots that are very stiff, so don't want to pop off to see if a leak, but it is pretty dry south of the whl cyl.
There is a tiny bit of wetness that starts just south of the axleshaft retainer flange.
I will presume this to be the squeaky-brake culprit. (until better evidence comes along, anyway)
Driverside brake looks A1, just some mild dust on the 'new' springs installed at the last brake job.
So:
I turn the passenger axleshaft and expect to hear lots of awful noise. However - it's quieter than any axle I can remember and it felt nice.
Both axles are turning the same direction, but it's kinda easy to turn them the forward direction.
Turning them rearward is significantly more difficult (and they also turn the same direction). IS THIS NORMAL???
The driveshaft is turning during all of this. I reached under to wiggle at the rear U-joint to see if any significant wear but it seems tight. (I replaced those U-joints years ago, and would guess to have 75k on them, so are due for inspection)
I put a screwdriver-stethoscope on the axleshaft retainer plate and rotated the shaft and heard minimal noise. It maybe sounded a little dry, but at this point I'm looking for bad, so the brain will invent it if necessary.
Driverside bearing sounded quieter and almost seemed like I could hear the other bearing thru the housing also.
Regardless, I didn't find anything that would seem to cause such an immediate noticeable noise.
Next steps are:
Remove the driveshaft and re-spin the axle.
Check the U-joints (they are due!)
Then remove axle shafts and feel the bearings.
But wanted some thoughts from you guys as well.
Video of spinning the axle:
Starts out showing forward rotation, via twisting the axle flange.
18 secs - reversing direction, which is significantly harder to turn.
30 secs - putting the drum on the axle studs for more leverage.
45 sec - ill-fated attempt with bungee cord to show other axle is rotating the same direction.
58 secs - installed tire to show direction.
Pic of under the wheel cylinder: