Looking for help identifying what is causing this noise....

[clifforddward]

New mystery today...here is the background...Drove my '31 Model A for the first time in 45 degree weather today...started normally, let it warm up for a couple of minutes and then left the house. 2 miles from home the noise heard in the video below started...I was driving about 30 mph at the time. Noise seems to come from behind the transmission, but I realize sounds can come from a different place than they occur. I immediately returned home and checked fluids...engine oil and trans oil levels were fine. I added lubrication grease to the U joint for good measure. Upon returning to the road for a test, the noise returned at about 15-20mph. Seems unrelated to clutch as occurs whether I have foot on clutch or not. Pitch of the noise seems related to driveline speed, not engine speed. Same noise regardless of which gear I am in.

Anybody have an idea of what's going on?

https://youtube.com/shorts/dAbwEgyOSHA?feature=share

[Bruce_MO]

Hearing stuff on YouTube videos is always a crapshoot for me, but it sounds to me like noises I’ve heard when a Speedo cable lacks lubrication or the lube is cold. Or maybe a generator bearing. Didn’t really sound like a driveline issue per se. good luck… hope it’s an easy one to find and fix.

[burner31]

Bee's, you have bee's...but properly what Bruce said...speedo cable

[Big hammer]

I see a Mitchell OD, that needs checking for fluid level and greasing a nipple on the front side of the gear box………….I wouldn’t drive before checking !!!!!!!

[CWPASADENA]

Originally Posted by Bruce_MO

sounds to me like noises I’ve heard when a Speedo cable lacks lubrication or the lube is cold.

I agree,

Disconnect the cable at the front of the torque tube and see if that helps.

Chris W.

[nkaminar]

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Check fluid in overdrive as Big Hammer says. The vent is a plastic tube that is installed so that it is higher than the box. If it has fallen down it could siphon out the oil.

[clifforddward]

Thanks Guys....O/D fluid check, related grease check, and speedo cable evaluation are now on my list of troubleshooting tasks for tomorrow...will report back on results...

[Benson]

Yes I have seen (heard) this before more than a few times.

Most likely the bushing inside speedometer that the magnet spins on is out of lubrication or oil has dried up.

The colder it is the worse the problem will be.

When temperature gets high enough it will go away

Eventfully the cable will break.

Suggest that while it is cold enough to have the problem, that you remove the cable AT the speedometer under the dash as mentioned above if noise goes away then that is the problem.

It is best to have a Speedometer person service it because if that bushing needs service then likely other bushings inside need service (cleaning and lube) also and too much oil (or the wrong oil) can ruin decals on the number wheels.

[clifforddward]

Thank you to all for the input...first thing this morning I checked the OD and related grease fittings (all were full and fine) so eliminated that possibility. Next I disconnected the speedo cable where it ties in with the OD cable...then went for a test drive...NO NOISE!...so I have narrowed things down to either the speedo assembly or the speedo cable.

As it turns out, I recently purchased a rebuilt speedo assembly...so have that available to install immediately. But I am wondering if I should first lubricate the speedo cable to see if that is what was causing the noise?...but since I'll need to pull off the instrument panel to get to the speedo cable, I'll be right there and could easily replace the speedo assembly. And while I'm at it, I have a restored instrument panel that I could also replace...and then why not go ahead and replace the speedo cable while I am there and be done with all of it, ready for the car to go forward without any risk of return problems.

If I decide to go ahead and replace the speedo assembly along with installing a new cable, are the new ones from the dealers (like Snyders) fine? Or am I better off with my old original being re-lubed if it is not damaged.

I feel myself stepping into the rabbit hole.....

Would appreciate any thoughts...

[nkaminar]

Speedometer cable lubricant is available from Snyders, see https://www.snydersantiqueauto.com/p...7016&cat=41744

I would try the lube first.

I only have experience with Model T speedometer but there is a small hole for adding oil. I would just use motor oil. Do not use WD 40 as it will dry and become gummy. You can run the speedometer with a battery powered drill motor and appropriate adapter or driver bit to see if it makes noise.

I am glad you found the problem.

[History]

I believe mine is doing the same thing. Took it for a spin and around 35-40 mph it’s started singing as yours did, slow down it goes away,,,,.

[katy]

You may be able to R&R and grease the cable from the bottom end. Try that first.

[clifforddward]

11/22 update....I got the speedo cable removed, cleaned, and relubed...it was certainly dirty and somewhat sticky so I strongly suspect the speedo was the cause of my noise.

Unfortunately I broke my Pop-Out switch while removing the speedo cable...have a replacement, just need time to do the installation...

So confirmation of noise fix will need to wait until I can get into the project during the next week or so. I'll send a final report once all is done.