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3AT just quit on me


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Gaskets for both styles of case
post-10866-0-89420000-1434169363_thumb.jpg

 

 

All the seals, O-rings, Servo pipes, thrust bearings [the long shafts at the top are not part of the kit]

post-10866-0-82905000-1434169373_thumb.jpg

 

When I ordered this, there were still about 8 left in stock.
About the same number of oil pump drive shafts were left also.

 

Servo pipes and some of the gaskets were no longer available separately.

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  • 5 months later...

It just quit.  I was pulling out of a parking lot, not really flooring it, and the engine revved under no load.  Absolutely no warning or other symptoms before it failed.

 

Since then, I've looked at all but one of the 6 or so I have, and all but one is showing signs of wear on the pump end.  The torque converter ends are fine.  There is no slop in the pump in one transmission I disassembled to get familiar with the internals, yet it has the same wear indications [not stripped]  The failed one had a bit over 200K miles.  The one from my 86 has NO indication of wear on the splines, it looks like the new shafts I bought.  It has around 200K on it also.

 

I could not find any pieces of the missing splines either, much to my surprise.

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... I could not find any pieces of the missing splines either, much to my surprise.

 

Some of the automatic transmissions and also manual transmissions, have a Magnetic drain bolt, I bet that you already checked it while searching for the Debris, but if you could Not find it, I kindly suggest you to do a complete wash / cleanup of all the internals in order to avoid future damage from that hidden debris.
 
Kind Regards.
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Yes, I know about the magnetic drain plug. The pieces could not have moved far, if they came off at the time of failure, since the pump stopped turning at that time. There isn't really anywhere for the pieces to go if they did shear off intact -

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If there is some failure mode that causes hammering ro occur, it wasn't noticeable while driving. The shaft is well under 1/2" diameter, so the force required to cause damage would be pretty small compared to those involved with moving the car.

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Spent some 30 years as a Machine Repair Tech in the Injection Molding Sector. Can't say I recall seeing a  pump shaft failure like that. Some of the pumps on those machines would do 3,000 PSI all day long, well above what an auto trans would see.

 

Can't give any insight to this. But thinking I would find a shop what deals in hydraulics and have them look at it.

Place like what would work on back-hoes, diggers, dozers and the likes.

Just to see if they had a decent answer.

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The various ones I have show varying degrees of wear. None are to the point where the shearing off looks imminent. It does seem to me that they gradually wear away. They all have had a change or 2 at least of atf. Nothing unusual in the color.

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Kindly let me ask you, if such "Hydraulic Hammering"

 

should be noticeable as vibration / knocking on the Drivetrain?

 

Kind Regards.

It would be in the form of a direct line pressure accumulator going bad, like a piston gets stuck and then any pressure fluxuations from gear changes dont end up pushing waves of fluid pressure back to the pump.

 

Water hammering in household pipes has a similar effect when the pressure is very high. Slamming a sink faucet shut quickly sends a pressure wave back through the pipe and if the pipe is loose in mounting it makes a solid bang!

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... Water hammering in household pipes has a similar effect when the pressure is very high. Slamming a sink faucet shut quickly ...

 

I know this effect on water pipings, thank you for the explanation, Now I understand.

 

I bet that the Driver have should felt such effect on the Transmission, prior to fail.

 

Maybe as hesitation prior to shift, at higher RPM's...

 

Kind Regards.

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