65 Take-off Noise (Groan) - Cruise Squeal/Chirp

[Brtele]

Ok, so I'm working towards addressing a couple of other outstanding items.

 

I have the following "noises" going on:

 

I have a very slight groan at initial take-off (0-3mph).  Can't feel it, just hear it.  It's only under load and I can't replicate it between gears when rolling - Only at initial take-off.  I know noises can travel, but it really feels like rear of the car.

 

Separate item: while cruising anywhere from 35-50mph, I sometimes (intermittently) get a chirping sound.  I could've swore it was birds chirping, but no way I'm hearing the same bird chirping along with me at 45mph, lol.  From reading similar threads this could be a center bearing?

 

I have not replaced my rear diff fluid, but have it planned in the near future.  This is a non posi rear.

 

I have also lightly greased all zercs I can find.  Rear driveshaft joint is sealed - no zerk.

 

Thanks for any pointers in the right direction.

Edited July 18, 2022 by Brtele (see edit history)

[telriv]

Most common is the front u-joint. Could also be the center bearing/support.

The slip yoke on the driveshaft has a plug in it that needs to be removed & a grease fitting installed. Then grease & re-install plug. IF you leave the fitting in it will most likely cause a slight vibration. DON'T over grease the slip yoke. A few pumps with a hand grease gun is all that's required.

 

Tom T.

[EmTee]

Agree - both the 'groan' and the 'chirp' make me think: U-joint.  Very well could be that one with no grease fitting... 

[RockinRiviDad]

Don’t know about the “groan” but the first thing I thought of about the “chirp” was a loose/worn belt under the hood. Check your belts for wear & tightness  

[Brtele]

Update - I was able to grease the Center Bearing plug a few weeks ago and have drove approximately 60 miles at various speeds and have yet to hear the chirping.  Fingers crossed. 

[60FlatTop]

Here is a squeak:

 

To find a groan look at the body mounts at the kick up of the frame directly above the rear axle and the body mounts just behind the rear wheel wells. In 1965 that upper cushion on each was about 2" tall. The mounts all the way at the rear are small oval ones that don't really do much. It is possible for the body to move across the frame slightly. Push hard on a pry bar and check  them.

[Brtele]

I'm pretty sure the groan is a u-joint - I can get it to do it at various speeds under 10mph with an increased load.  It also presents itself above 55mph when I let off the gas.  But the chirp is definitely gone after center bearing greasing.  I guess the driveshaft rebuild is now on the winter list - kind of higher priority - time to start the exhaustive research procedure.

[60FlatTop]

I have only replaced the center bearing/mount and the five U-joints and a right rear axle bearing in the 40+ years I owned the car. I would avoid doing any service other than cleaning and lubricating the Cardan, CV, joint balls. My luck with Cadillac CV joints has been terrible. the best shop in the city could not get them right. I would look for a better used driveshaft before try to service one.

 

When I changed the CV joint U-joins I found that the shell of the body would not let me drive the bearing cups out as the cross bottomed out before the cups came through enough to grip. I used a cutting torch the cut the bearing cross out. And then knocked the cups out with a drift.

 

Although I can buy CV joint repair kits the shop manual says the shaft is not a serviceable part. I have a few hundred bucks invested into proving the book to be right.

 

My experience, others may vary. I had expectations on how it should feel. Good luck.

[Brtele]

38 minutes ago, 60FlatTop said:

I have only replaced the center bearing/mount and the five U-joints and a right rear axle bearing in the 40+ years I owned the car. I would avoid doing any service other than cleaning and lubricating the Cardan, CV, joint balls. My luck with Cadillac CV joints has been terrible. the best shop in the city could not get them right. I would look for a better used driveshaft before try to service one.

 

When I changed the CV joint U-joins I found that the shell of the body would not let me drive the bearing cups out as the cross bottomed out before the cups came through enough to grip. I used a cutting torch the cut the bearing cross out. And then knocked the cups out with a drift.

 

Although I can buy CV joint repair kits the shop manual says the shaft is not a serviceable part. I have a few hundred bucks invested into proving the book to be right.

 

My experience, others may vary. I had expectations on how it should feel. Good luck.

I've read through your trials and tribulations when I started having some shaft issues.  Are you stating you would recommend replacing the u-joints on the front and rear of the shaft?  I was going to leave the middle "stuff" alone.

[60FlatTop]

I read your plan of a driveshaft rebuild as replacing the wear parts with new. I would replace all five U-joints. Even if they have been greased the grease has been tacking the path of least resistance for 50 years now. 20 cups, 1 could be dry, maybe more.

 

My trouble with pushing the caps out using the cross may only apply to early Cardan castings.  I looked at some images online and later models appear to have a more open casting and a replaceable pivot ball rather than a welded one. They sure look more serviceable.

 

I like to assemble U-joints in my large vice. It gives me better control and I can always check the tightness as I close the cups in. I am just not a hammer guy. My nephew knows that and since I am getting old I took one of my cars to his shop to put a pair in one of my cars. He usually uses a hammer. He decided to use his press to make me feel comfortable. Screwed up the job and split the top disc out of the cup. We threw out my super duty bearing and drove a good 40 miles to find a standard replacement. The moral of that story is keep doing things the way you always do them. You have your own technique. That's just a tip for life.

[telriv]

AND, make sure the proper joints have the recess in them for the proper clearance needed.

 

Tom T.

[Brtele]

I recently replaced a bunch of transmission "stuff" and had the driveshaft out.  None of the u-joints needed to be replaced and the center support bearing/rubber was in fair shape (not brand-new - but nothing alarming).  But this groan is growing and is starting to show it's teeth in 2nd gear also.  I can manipulate the load/speed to keep it right in the "groan" area.  When I shift into Neutral all noises go away (makes me believe it has nothing to do with the driveshaft).  While freewheeling in neutral, I can get the groan to present itself by applying a little throttle (maybe 2k rpm - both on the way up and down).  It also will make a slight groan while the car is in park and apply a throttle.

 

I know (1) motor mount probably needs to be replaced - so i'll replace both.  Hoping motor mount replacement isn't too bad of a mountain to climb.

[telriv]

Brtele,

 

The mounts IMO are fairly easy to replace.

BUT, I don't think it may have anything to do with the groan. 

I would be more inclined to suspect the trans. mount.

 

Tom T.

Edited December 21, 2023 by telriv (see edit history)

[1965rivgs]

  Maybe the fan is hitting the shroud due to the bad motor mount?

Tom Mooney

[Brtele]

11 minutes ago, telriv said:

Brtele,

 

The mounts IMO are fairly easy to replace.

BUT, I don't think it may have anything to do with the groan. 

I would be more inclined to suspect the trans. mount.

 

Tom T.

I would definitely agree, and that's why I replaced the trans mount.  Changed it within the last week and it made absolutely no difference.  Thanks for the recommendation tho!

[Brtele]

11 minutes ago, 1965rivgs said:

  Maybe the fan is hitting the shroud due to the bad motor mount?

Tom Mooney

I'll take a look at the shroud and see if there are any marks. Thanks,

[EmTee]

14 hours ago, Brtele said:

When I shift into Neutral all noises go away (makes me believe it has nothing to do with the driveshaft).  While freewheeling in neutral, I can get the groan to present itself by applying a little throttle (maybe 2k rpm - both on the way up and down).  It also will make a slight groan while the car is in park and apply a throttle.

OK, I agree, that seems to remove the driveshaft and rear axle from the equation.  I wonder whether there's something going on with the flexplate or torque converter.  First thing I'd do is remove the inspection cover and check the converter bolts on the flexplate to make sure they are tight and look for evidence of any cracks around the bolt holes.

 

Another thought - I notice an occasional 'moan' when my Riviera is running in park with the hood open.  it sounds like it is coming from the vicinity of the air cleaner (note that I currently have a K&N filter installed).  It's not always there, but my guess is the intake air is exciting the air cleaner cavity like a Helmholtz resonator.  Changing the throttle position seems to stop it.  Maybe try removing your air cleaner and taking a drive without it just to rule that out as a possibility.

Edited December 22, 2023 by EmTee (see edit history)

[XframeFX]

On 12/21/2023 at 3:08 PM, Brtele said:

While freewheeling in neutral, I can get the groan to present itself by applying a little throttle

Brandon,

Maybe it is the Motor mount and your manipulation has the engine lifting off the Driver's side causing some part of the exhaust to touch the frame or floor boards.

A shot in the dark, who knows what exhaust pipes you have?

 

 

 

 

 

 

 

Edited December 23, 2023 by XframeFX (see edit history)

[Brtele]

I had a chance to start up the car yesterday and poke around.  It's not the motor mount, or the fan blade hitting anything.  The AC compressor or the Alternator would make a very little bit of noise when I would blip the throttle hard for a quick second, but it's not the noise I'm hearing.  (Knock on wood) - the engine and engine bay started up easily and ran through the choke procedure as designed - couldn't hear a noise at all.

 

Got into the car, pulled into the street and immediately heard the noise as I took off.  Got it to do it the entire run around the block.

 

Got back in the driveway and opened the door - I believe it's coming from the driver's side exhaust pipe.  I didn't have someone with me, but it's definitely coming from underneath the car and I can get it to do it in Park/Neutral.  Motor mounts arrived, but have been put lower on my priority list.

[1965rivgs]

1 hour ago, Brtele said:

I had a chance to start up the car yesterday and poke around.  It's not the motor mount, or the fan blade hitting anything.  The AC compressor or the Alternator would make a very little bit of noise when I would blip the throttle hard for a quick second, but it's not the noise I'm hearing.  (Knock on wood) - the engine and engine bay started up easily and ran through the choke procedure as designed - couldn't hear a noise at all.

 

Got into the car, pulled into the street and immediately heard the noise as I took off.  Got it to do it the entire run around the block.

 

Got back in the driveway and opened the door - I believe it's coming from the driver's side exhaust pipe.  I didn't have someone with me, but it's definitely coming from underneath the car and I can get it to do it in Park/Neutral.  Motor mounts arrived, but have been put lower on my priority list.

  If the motor mount is bad, and if the engine lifts off the mount when you load the drivetrain,  then that is changing the relationship of the header pipe to frame and floor. If the engine mount is bad you might as well get it swapped out as you`re going to do it eventually anyway.

Tom Mooney

[XframeFX]

3 hours ago, Brtele said:

Motor mounts arrived, but have been put lower on my priority list.

I was about to order fresh motor mounts. I'll take those Thank-You!😄

[XframeFX]

On 12/27/2023 at 10:22 AM, Brtele said:

Motor mounts arrived, but have been put lower on my priority list.

Brandon must've acquired the LAST PAIR of Motor Mounts if they were Anchor Brand. Everywhere I've searched have only 1 available including Rock Auto, proof they draw from the same stock.

My motor mounts must be an economy brand, they are rock hard.

Anchor is the only Brand considered Premium. Of the other 4 brands, 3 stopped with only Westar #EM2216 (economy brand) available.

Gawd, hoping this is not going to be another window closing under my nose!

[BulldogDriver]

You can see if he still has a pair of these. Not cheap and you will have to change the trans mount to a poly to keep everything shaking together. It’s what’s on mine and shouldn’t need to be replaced again. 
 

https://polybushings.com/pages/2219.html

 

Ray

[XframeFX]

2 hours ago, BulldogDriver said:

It’s what’s on mine and shouldn’t need to be replaced again. 

Learn something everyday here. I never knew they existed for Motor Mounts. Ray, how does your 1963 Nailhead (JT like mine) run with these motor mounts? A delinquent Nailhead would like to know!

 

Thanks for the referral but polyurethane mounts are the opposite direction I want to go. Without a durometer test, I suspect my replacement Motor Mounts have aged to rock hard. I also suspect applying Dynamat to the Riviera's entire floor pan has significantly changed the dynamics of the passenger compartment.

If I had my way, I'd suspend my Nailhead like the drum in my front load washer! I can't put my finger on any of my thumping other than the Nailhead is the source of excitation. I want soft mounts.

 

 

 

 

 

Edited December 30, 2023 by XframeFX (see edit history)

[BulldogDriver]

I’ve had no extreme issues using poly mounts. You do need to match engine ands trans though. My Nailhead does have a mild cam in it, don’t know which one, it in it when I got the car so there is a mild lope at idle. Running do the road I can’t tell any difference from before and I drove it cross country, 3000 miles. 
 

A positive thing about these mounts is if the poly fails, the mount is designed to stay together and not cause a fan strike on the shroud. 
 

Ray

Edited December 30, 2023 by BulldogDriver (see edit history)

[XframeFX]

13 minutes ago, BulldogDriver said:

You do need to match engine ands trans though.

So, I assume the Trans mount is Poly as well. Would that be a one hole or 2-Hole trans mount?

[BulldogDriver]

I have a 4L60E behind my Nailhead. Doesn’t matter which transmission, still need to match mounts. 
 

Ray

[Ed R]

On 12/27/2023 at 12:22 PM, Brtele said:

I had a chance to start up the car yesterday and poke around.  It's not the motor mount, or the fan blade hitting anything.  The AC compressor or the Alternator would make a very little bit of noise when I would blip the throttle hard for a quick second, but it's not the noise I'm hearing.  (Knock on wood) - the engine and engine bay started up easily and ran through the choke procedure as designed - couldn't hear a noise at all.

 

Got into the car, pulled into the street and immediately heard the noise as I took off.  Got it to do it the entire run around the block.

 

Got back in the driveway and opened the door - I believe it's coming from the driver's side exhaust pipe.  I didn't have someone with me, but it's definitely coming from underneath the car and I can get it to do it in Park/Neutral.  Motor mounts arrived, but have been put lower on my priority list.

I had some nasty intermittent groans and bangs from the rear end.  Turned out to be the exhaust piping hitting the body over the rear axle and the muffler hitting against the gas tank.  The system was also bolted together and leaking at the junctions.