Page 1 of 7 1 2 3 4 5 6 7 >
Topic Options
#2458732 - 02/28/18 05:35 AM Can anyone confidently identify this noise? A833 4 speed
moparedtn
Unregistered


1968 Plymouth GTX, mild early 70's 440, 11" CenterForce DualFriction, new input bushing, 23 spline of unknown sourcing (looks to never have been apart, shifts great though). 3.55 SG fresh, original driveshaft.
There is a noise that sounds much like an old school buzzer that eminates at speeds above 50mph and remains constant above that; it goes away consistently below that speed and finally does go away at 70+ mph.
Everything in the clutch/flywheel is new and Brewer's sourced.
Tailshaft bushing and seal are also new. Speedo gear is new as well; I had it out to inspect and it's flawless and I've eliminated the cable as a possibility as well.

The noise is not engine speed dependent; only vehicle speed makes it happen, whether clutch in/out, regardless of gear (or in neutral). Revving the engine in neutral, no difference.
It comes on all at once, like a light switch being flicked.

I have a video on YouTube of it occurring in real time:
A833 Noise - Speedometer Disconnected at Transmission

Can anyone confidently recognize this noise?
TIA!!


Edited by moparedtn (02/28/18 06:03 AM)

Top
#2458767 - 02/28/18 08:34 AM Re: Can anyone confidently identify this noise? A833 4 speed [Re: ]
blewbyu Offline
master

Registered: 01/22/03
Posts: 3615
Loc: Florida
I figured it out you are driving a Superbee not a GTX by the sounds of that Buzzing noise. bump

Top
#2458833 - 02/28/18 10:38 AM Re: Can anyone confidently identify this noise? A833 4 speed [Re: ]
moparedtn
Unregistered


Somebody surely recognizes that sound??

Top
#2458853 - 02/28/18 11:02 AM Re: Can anyone confidently identify this noise? A833 4 speed [Re: ]
71birdJ68 Offline
master

Registered: 02/09/12
Posts: 4012
Loc: Morristown Tn.
Sounds kind of like some sort of bushing, or bearing. Does the engine have a cast crank, and if so, does it have the proper flywheel, and balancer? I'm in Morristown, maybe we can get together and figure it out.


Edited by 71birdJ68 (02/28/18 11:06 AM)

Top
#2458868 - 02/28/18 11:13 AM Re: Can anyone confidently identify this noise? A833 4 speed [Re: ]
buildanother Offline
I Live Here

Registered: 08/30/05
Posts: 11288
Loc: chicagoland,usa
I hear it, sure don't know what it is. But first thing I would do is grab shifter handle, try moving a hair each way to try to change noise. gives ya a better idea where to look. Be very weird if it ends up as a relay buzzing somewhere.

Top
#2458930 - 02/28/18 12:55 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: ]
Brewzer67 Offline
member

Registered: 05/12/17
Posts: 48
Loc: WI
That sounds like a speedometer cable binding at/near the transmission to me. That is exactly what my dremel tool extension cable sounds like when I get it in too tight of a loop/radius. I would disconnect the speedo cable and see if it goes away. If the cable is clipped to the floorboard to keep it in place it would make a perfect sounding board for it.

Top
#2458993 - 02/28/18 03:03 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: 71birdJ68]
moparedtn
Unregistered


Originally Posted By 71birdJ68
Sounds kind of like some sort of bushing, or bearing. Does the engine have a cast crank, and if so, does it have the proper flywheel, and balancer? I'm in Morristown, maybe we can get together and figure it out.

Hey, that's very gracious of you. I'd kill for access to a lift right now. :-)
Darn good question on the engine and I don't know for sure, but when I got the engine in shipping, I took pictures and posted on the FBBO forum and asked others' opinions. The consensus was that it was forged and since it came with those types of balancers and flywheels, I called it good.
If the problem was a gradual harmonic vibration that became stronger (or lesser) with speed, I'd certainly be looking at that possibility, though, sure - but it isn't, as you can hear.
This comes on all at once with a certain speed.

Top
#2458995 - 02/28/18 03:05 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: buildanother]
moparedtn
Unregistered


Originally Posted By buildanother
I hear it, sure don't know what it is. But first thing I would do is grab shifter handle, try moving a hair each way to try to change noise. gives ya a better idea where to look. Be very weird if it ends up as a relay buzzing somewhere.

Oh trust me, the shifter got wrangled every which way, including "more in gear", out of gear, every position short of reverse while going down the highway. Nada.
Sounds like an old seat belt buzzer, eh? :-)
It isn't. There's nothing in that area electrical, short of the reverse light switch of course.

Top
#2458996 - 02/28/18 03:07 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: Brewzer67]
moparedtn
Unregistered


Originally Posted By Brewzer67
That sounds like a speedometer cable binding at/near the transmission to me. That is exactly what my dremel tool extension cable sounds like when I get it in too tight of a loop/radius. I would disconnect the speedo cable and see if it goes away. If the cable is clipped to the floorboard to keep it in place it would make a perfect sounding board for it.

Thanks (and I agreed with you initially because that's what it sounds like), but as I posted, the speedo gear and cable are no longer suspects. In fact, the speedo cable is disconnected at the transmission at the time I made the video in the hopes that would have cured it.
Sadly, it didn't.

Top
#2458997 - 02/28/18 03:09 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: ]
moparedtn
Unregistered


Thanks for all the guesses so far. I appreciate the help!
Man, I'm hoping someone hears it and says "well sure, dumbass, it's this!" :-)

Top
#2459006 - 02/28/18 03:31 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: ]
moparpoolman Offline
enthusiast

Registered: 11/27/06
Posts: 328
Loc: NE
Does it do it when in 2nd? Could be the shift fork rattling?

Top
#2459088 - 02/28/18 07:01 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: moparpoolman]
moparedtn
Unregistered


Originally Posted By moparpoolman
Does it do it when in 2nd? Could be the shift fork rattling?

I tried every shifter position short of reverse.
Thanks!

Top
#2459146 - 02/28/18 08:37 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: ]
fourgearsavoy Offline


Registered: 12/07/04
Posts: 9330
Loc: Rittman Ohio
It does sound like a dry bushing but you have covered all the usual suspects. The only thing I can think of would be trying a differn't speedo adapter then see if someone can loan you a differn't drive shaft. You cant feel it through the shifter? Does it stop when you kick it into neutral?

Gus beer
_________________________
64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60

Top
#2459191 - 02/28/18 09:44 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: fourgearsavoy]
moparedtn
Unregistered


Originally Posted By fourgearsavoy
It does sound like a dry bushing but you have covered all the usual suspects. The only thing I can think of would be trying a differn't speedo adapter then see if someone can loan you a differn't drive shaft. You cant feel it through the shifter? Does it stop when you kick it into neutral?
Gus beer

I gotta figure if the speedo pinion is in perfect shape (it is) and the speedometer itself works flawlessly, then I got the "lash" set correctly on the adapter. I suppose I could just pull out the pinion and plug off the hole in the adapter, then give that a shot?
I'm gonna do it. What would it hurt to try? Thanks!

No sir on the neutral. Again, shifter position and clutch position do not affect the noise at all. Any gear or neutral, doesn't matter.
Thanks!


Edited by moparedtn (02/28/18 09:46 PM)

Top
#2459353 - 03/01/18 09:53 AM Re: Can anyone confidently identify this noise? A833 4 speed [Re: ]
68LAR Offline
master

Registered: 10/10/03
Posts: 3748
Loc: South Park, Pa.

Can anyone confidently recognize this noise?
TIA!! [/quote]

Sounds to me like rear main bearing in the transmission??????
_________________________
4 speed street legal. Best time 10.99 @ 124mph on 93 octane pump gas

Top
#2459446 - 03/01/18 01:07 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: 68LAR]
6PakBee Offline
master

Registered: 01/20/03
Posts: 5690
Loc: North Dakota
Okay, if I've got this right.

1) Noise is dependent on road speed, not engine speed.
2) Noise is present in neutral with enough road speed.
3) Noise is present with clutch depressed and enough road speed.

If the noise is present in neutral with the clutch depressed and enough road speed, the only thing that is rotating is the output shaft. I think the rear main bearing is a good guess.
_________________________
Wife says too many cars, liquidation coming soon......

Top
#2459463 - 03/01/18 01:39 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: 6PakBee]
68LAR Offline
master

Registered: 10/10/03
Posts: 3748
Loc: South Park, Pa.
Originally Posted By 6PakBee
Okay, if I've got this right.

1) Noise is dependent on road speed, not engine speed.
2) Noise is present in neutral with enough road speed.
3) Noise is present with clutch depressed and enough road speed.

If the noise is present in neutral with the clutch depressed and enough road speed, the only thing that is rotating is the output shaft. I think the rear main bearing is a good guess.


1) as long as the rear tires are rotating, the rear main bearing is rotating.
2) As long as the rear tires are rotating, the rear main bearing is rotating
3) as long as the rear tires are rotating, the rear main bearing is rotating. When clutch is depressed, the input shaft stops rotating, hense, the front bearing stops rotating.
_________________________
4 speed street legal. Best time 10.99 @ 124mph on 93 octane pump gas

Top
#2459501 - 03/01/18 03:00 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: ]
71birdJ68 Offline
master

Registered: 02/09/12
Posts: 4012
Loc: Morristown Tn.
What are you mean when you say the lash is correct on the pinion adaptor?

Top
#2459523 - 03/01/18 03:38 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: ]
Cuda340 Offline


Registered: 12/09/04
Posts: 2036
Loc: Wheatfield, NY
It could also be the rear bushing in the tailshaft, where the slip yoke rides... Pull out the slip yoke and see what the machined surface looks like.


Edited by Cuda340 (03/01/18 03:53 PM)

Top
#2459525 - 03/01/18 03:39 PM Re: Can anyone confidently identify this noise? A833 4 speed [Re: 71birdJ68]
Cuda340 Offline


Registered: 12/09/04
Posts: 2036
Loc: Wheatfield, NY
Originally Posted By 71birdJ68
What are you mean when you say the lash is correct on the pinion adaptor?


There are three different settings for the speedo adapter depending what tooth the speedo gear is. I think that is what he was referring to .

Top
Page 1 of 7 1 2 3 4 5 6 7 >

Advertisement
Forum Stats
25,624 Registered Members
32 Forums
195,527 Topics
2,287,227 Posts

Most users ever online: 1,424 @ 06/20/18 07:18 PM
Moparts Newest Topics
650 HP '69 Dart
by RoadRunnerLuva
16 minutes 12 seconds ago
1971 cuda project
by biggE
Today at 12:10 PM
Do you still live near where you grew up?
by BSharp
Today at 11:34 AM
FG DOOR INSTALL
by A/MP
Today at 11:14 AM