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Turbo Hydramatic 400 problem.

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Old Jul 23, 2018 | 10:45 AM
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Default Turbo Hydramatic 400 problem.

My 1969 350 Cubic Inch, 300 Horsepower automatic transmission seemed to be working well. Cowtown Cars and Coffee had a gathering at Texas Motor Speedway this Saturday. After the event owners were allowed to take a few laps around their steeply banked NASCAR track. I did that. On the way home I started hearing and feeling "clunks" from the transmission. Is it possible that the steep bank allowed the transmission fluid to flow away from the pick up and under strain damage the unit? Any suggestions for the rebuild? Thanks. Dennis
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Old Jul 23, 2018 | 11:15 AM
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Originally Posted by Dennis Murawski
My 1969 350 Cubic Inch, 300 Horsepower automatic transmission seemed to be working well. Cowtown Cars and Coffee had a gathering at Texas Motor Speedway this Saturday. After the event owners were allowed to take a few laps around their steeply banked NASCAR track. I did that. On the way home I started hearing and feeling "clunks" from the transmission. Is it possible that the steep bank allowed the transmission fluid to flow away from the pick up and under strain damage the unit? Any suggestions for the rebuild? Thanks. Dennis
You would've known if it ran out of fluid. Anyway, if you were going fast enough, centrifugal force would've kept the oil in the pan where it's supposed to be.
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Old Jul 23, 2018 | 02:50 PM
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when do the clunks occur, when you are standing still and shift from P into D or when the car is moving?
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Old Jul 23, 2018 | 03:24 PM
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Worn out u-joints will clunk...
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Old Jul 23, 2018 | 07:55 PM
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Originally Posted by MelWff
when do the clunks occur, when you are standing still and shift from P into D or when the car is moving?
When the vehicle was moving and especially when it was in reverse.
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Old Jul 23, 2018 | 11:51 PM
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Well, on those race tracks they don't allow you to go as fast as you need to put the oil where it should be. But, I would think you'd know that the trans was starving for oil at that time.

Could be a coincidence...or perhaps the track event put some 'new' stress on some old parts.
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Old Jul 25, 2018 | 03:05 PM
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I had coffee with a friend this morning. He had a C3. He said what I was describing was exactly what he experienced when his Positraction went out. We'll check it out.
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Old Jul 25, 2018 | 05:03 PM
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Originally Posted by Dennis Murawski
I had coffee with a friend this morning. He had a C3. He said what I was describing was exactly what he experienced when his Positraction went out. We'll check it out.
Post what you discover/pics if you have them for future reference (as mentioned, you may want to check all the u-joints and diff. rubber snubber first just in case)
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Old Jul 26, 2018 | 05:15 AM
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Originally Posted by Dennis Murawski
I had coffee with a friend this morning. He had a C3. He said what I was describing was exactly what he experienced when his Positraction went out. We'll check it out.
For the OP, try changing the dif fluid, make sure you add the posi supplement. T
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Old Jul 26, 2018 | 02:41 PM
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How about the front rubber bushings on the differential mounting bracket to frame
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