Transmission problem

[bulli bulli 33]

Hi, has anybody some experience with 356 transmissions? I have a laud grinding noise over 3000 rpm when I stop accelerating. It's a 1960 T5 356 Outlaw with an 912 engine, we had the transmission opened and didn't find nothing wrong! What didn't we see, please advice.

[Jacks]

I've had noise problems in the past with generators and exhaust that sound like transmission. Try driving briefly without the fan belt, and beat on the muffler to check for loose baffles. Your aftermarket one looks suspect.
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Jack Staggs
Actual name

[bulli bulli 33]

I am sure is not that, i drive a second generator and a new custom muffler.

[Jacks]

Does your car have a cooling fan attached to the end of one of your generators?
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Jack Staggs
Actual name

[bulli bulli 33]

of course, and I only have one generator, I just change it for a new one! Grinding definitely comes out of transmission, but the question is why. The sound is quite terrific, like crushing stones.

[Starbucket]

Sounds like the ring & pinion gears have lost their correct alignment, maybe thrust washer has worn or failed or carrier bearings are shot (my guess). You need to remove the R&P and clean everything in solvent and inspect with a 10X eye loop looking for pitting. If all is good re-blue the gears and adjust for proper contact.

[Jacks]

I have done hundreds of transaxle repairs over 40 years, including 356, 901, 915, and VW. Several years ago, after overhauling a broken transmission, I had a 356 trans apart 3 times to find a noise that sounded like yours, crazy noise ONLY ON DECELLERATION at higher RPM. I finally fitted a different engine and THE NOISE WENT AWAY. I was able to trace the source of the noise to the cooling fan rubbing on the shroud. This did not occur while revving the engine without driving the car! If I had driven the car without the fan belt, I could have saved dozens of hours of work. You asked for advice, but you did not like it. Try it. What do you have to lose? 10 minutes?
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Jack Staggs
Actual name

[Jacks]

[bulli bulli 33]

Thank you guys, I will try it without the belt. If this will be the case I be more then happy
Waiting for better weather conditions.

[AXAM]

Just my two sense.
When Driving it at the rpm where the noise occurs. Try a couple things.
Press the clutch pedal in torwards the floor and see if the noise stays there. Keep the rpms at the level the noise appears. If no noise let the clutch back out and try it with letting the rpm drop.
As mentioned by another knowledgeable trans builder it could be the carrier bearings or either the mainshaft or pinion bearing.
As others advised you, check your fan for any debris stuck back there. That could give you a noise also.
Have you jacked the car up on a rack and listened for the noise. If you have a shop or friend with a rack. Have someone sit in the car and raise the car. Accelerate like normal to the rpm the noise occurs and get a stetascope and listen at the side covers, axle bearing and just all around the trans.
That's the best way to diagnose the source of the noise.
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Life is Good! Have a Nice Day!-don't worry about the jerks out there on the forum, in the end... they fall, and fall hard!
Peace!

[bulli bulli 33]

Thanks AXAM, this are promising tips!