VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Sudden Grinding Sound

Took my 38 for a spin around the block and suddenly I heard a grinding sound coming from what sound like the passenger side under the front seat. The grinding started after a couple of blocks as though something is rubbing on the bell housing. The noise is cyclical and even when I put her in neutral. Sounds like something is loose.
Thanks
Mike A

Mike A,

It may be one of the following, but not limited to any one of them:

a. Clutch spring or something other thing related to the clutch's pressure plate.

b. A bearing in the transmission

c. U-Joint (noise telescoping)

d. You ran over, and are now dragging, large and highly upset doberman pincer. (inspect carefully)

Charlie

Seems like one thing after another. I haven't had a chance to troubleshoot, but never heard this sound before. I think something came loose like the sound of something rubbing against a heat shield.
Mike A

It could be many things but the 1st thing I would check is make sure the tin flywheel cover has not come loose allowing the flywheel to rub on it.

Check the gearbox oil level while you are under the car also.

X2

Thank you Ed and Tiny, will check cover.
Jack speaking of gearbox, I looked at my 38 manual over and over To ckeck gearbox level and cannot find how to check level, fill or drain. I keep thinking the access is under a floorboard access whole.
As technically simple my 38 is, it is also a pain in the neck and it sounds like experience is the best teacher. I am a black and white type thinker and do not do well when the answer is in the gray zone.
If I had the means I would have my 38 rebuilt frame the frame up and start there, but I don't so I have to maintain her and fix her when she breaks.
Thank you all for the advice, it really helps and it is great to know there are so many experienced vintage Chevrolet owners going through the same things I am and still loving it. Still haven't gotten my brakes straightened out yet but have some pedal now.
Mike A

Although I haven't worked on the transmission of my 38 yet, I would assume that there is a fill plug in the side. Normally one would remove the plug and check that the fluid is up to within 1/2" of the hole. That is how it is done on my truck.

You should have two plugs on the side of the transmission. The bottom one to drain and the top to fill. Fill until it starts to run out of the hole. If you pull the top plug & can feel the oil with the tip of your finger you have enough.

You can see the plugs here in Fig. 13.

Thank you gents, your advice makes perfect sense. I picked up gear oil and a grease gun to start lubing her old bones. While looking through my 38 manual I noticed a topic for lubing the water pump, but maybe it was for a truck. Does the water pump on a 38 Master Deluxe 216 have a oil reservoir?

Early dd and late did not. Also replacements did not. T would doubt if any of the early 1938 water pumps still exist.The original 1937 and 1938 water pumps had a short life.
Cars and trucks were the same.

A good idea to make sure the universal is lubed as well .. is a fill bung opposite side to the speedo cable/ Right top rear of g-box housing .. from what i understand it will level out with the gearbox through the output shaft bearing so let any overfill out of the fill plug hole .. I use a large auto syringe and clear tube to get her done..

Good news. The grinding noise was the tranny and fortunately I did not travel far. The tranny was empty so I filled to overflow as well as the rear end. Thanks all for the suggestions.
Mike A

Glad it is fixed , another good example of look for the simple things first before tearing everything apart.

...but ist again a clear sign that cars get revenge if they dont get their necessary Service as recommended in the service manual

Stefangermany

I have to condition myself to remember she is a 1938 and not a modern, relatively, carefree car. I did discover my aftermarket tank is taller than the original when I tried to install the stock exhaust hangar purchased from ebay. I will have to mod the hangar or manufacture a replacement, the coat hangar might be period correct, but not the preferred option.
Mike A

Being that the tranny was empty, where did the tranny fluid go ?

Lucky! I once went up a hill and there was a bit of a noise there but then again there always is. Then the car stopped. The transmission had simply seized. Filled it up and it went well enough to get me home and get it rebuilt. That won't happen again!

I can only guess it leaked out over time. I really don't know much about the maintenance program of the previous owner.
What are your thoughts?
Mike A