700R4 behind a TBI 350 in my '64 C10. Transmission was a new unit from Phoenix Transmission a few years ago. Great unit, been very happy with it. Drove it to a job, everything was fine. When I went to fire it up and leave, after a minute I hear a fluttering sound which I first thought was a piece of paper caught in the fan blade or something. So I shut it off, pop the hood, and actually see that a transmission rubber line had somehow backed itself off the hard line (due to pressure?) and ATF was gushing out. I was right in the way of other people, so I fired it up and drove it about 50 yards over to a parking spot and shut it down again. I then managed to reattach the rubber line to the hard line and cinch it back down with the hose clamps. I fired it back up again and went to drive off to find some fluid, but the truck wouldn't go into drive or reverse. I could shift it into gear, but the truck wouldn't move when applying throttle (would just rev). At that point I simply called a tow truck and got it home. The next day I put 3 quarts of ATF (Dexron VI) in it and that brought it back up to the full level. I then went for a drive and everything seemed fine except for a new light grinding/rattling noise that is a bit louder during acceleration and quieter while coasting. The truck drives and feels like it did before though. The only difference is the new noise. What do you all think? Did I fry something? Is it about to break down on me again?
my guess is that you are over-concentrating on listening for damage....and it could be just a rattle from a loose part hitting something on the chassis or exhaust, etc. .
Oil on the belt can make it slip and create a slapping noise. draw a sketch how the belt is routed,remove it wipe the pulleys off w/brake clean on a rag and replace the belt if its saturated w/ oil.
I would doubt you could have caused any damage with the scenario you described. When you re-did the lines to repair them, do you now have a line rubbing against something or rattling against something ? I do agree with F+J that you may be "hearing things". Good luck
It is possible to damage the pump from running it dry. They are usually robust enough to survive moderate consumer inattention to fluid levels, and it sounds like you only operated it for a very short time, but if there is damage, it most likely would be the pump. Maybe just some cavitation damage done, and not enough to cause if to fail. Pumps are not a hugely expensive repair, but the trans does have to come out to replace it.
I would drive it and see if it gets worse. If it is hurt it will have to come out anyway. Noise could be the belt as said.
check the fluid frequently ,looking to see if it darkens. For now you could remove the pan clean it and change the filter.
Thanks for the input guys. So I poured in another quart of ATF, bringing it up to just past max full on the dipstick. I also changed the serpentine belt at the same time (wiping down the pulleys while the belt was off too). The noise is now gone. However, I don't know what exactly fixed it since I did both items at the same time. Doh. I'll take it on a longer test drive tomorrow.
I would get that oil just to the full mark or you might have the transmission problems you didn't want before.
I bet the oil had air whipped in it after you just added it, and that is what made the noise. After it sat a while the level went down as the air bubbles came out of it so you added more oil. Now with no air bubbles in the oil the trans is quiet.
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