Technical 46 Chevrolet whines in third gear.

I've got a customer's car here That's a stock 46 Chevrolet Fleetmaster that whines in third gear. I've got the transmission cover off the floor and can feel it in the transmission. I can make it come and go with the throttle. On the throttle, it whines and off the throttle, it does not. Gonna tear into the trans, anything to look for? Possible worn gears? I figured if it was bearings, it would do it in every gear.

 

rearend gears? The transmission gears are not doing anything when it's in 3rd, they're just idling along for the ride, since the input and output shafts are connected together by the synchronizer.

 

I figured it could be the rear end pinion bearing assembly, but it does wine a little bit in second, just not as loud as in third.

 

If it was the Rear end it should make noise all the time, right.

 

It would vary with load.

The thing about it is that the gears in the transmission are not under any load at all in High, so it seems strange that you get a noise that varies with load, if the noise is indeed from the transmission. And since it's a torque tube rear, noise will travel from the rear to the transmission.

 

Gotcha

 

had a 49 Buick that I "heated" up the rear end on. I drove my 50 Fleetline down to LA to trade for a "kustom". On the drive back, things started making noise. No oil in the diff.. Massive gear lash. Sounded like a turbine engine starting up. I was Navy poor and it was a daily, so I drove it like that for about a year. Never should have traded the Fleetline, but I am dumb.

 

Gonna pull the cover on the rear end and see what I can see.

 

OK....

Lube....
What lube is used in the rear? This stuff has changed through the years.
The older stuff was a lot thicker.
Maybe the dope is contaminated or burnt.

The Lucas dope is sticky it’s kind of like “Jogging in a Jug” for cars.
I don’t like cures in a can, but simple stuff like checking or changing dope may be the first thing to try.

 

Sometimes the rear bearing on the main shaft or even universal.

 

So the customer just told me that when he got the car the trans And rear end were empty and he drove it for a while like that. Upon inspection of the rear end, the gears are like a mirror and Almost bluish and it has a lot of slop Between the ring and pinion. The oil was like metal flake paint That I Drained out. I cleaned it all out and filled it with a quart of Lucas and the rest regular gear oil and it's a little bit quieter. Thanks for all the suggestions.the end.

 

bummer, but now you know what happened.

 

Sounds like pertinent information that he should have mentioned right off...

 

Yup