[Shop-talk] An off shoot of the Toyota debacle.....

[Arvid Jedlicka]

Tim,

Thanks. We agree on how it works with just an input pump and various 
scenarios of the engine running, not running, in a gear, not in a gear, etc. 
But the original statement from John ...

----- Original Message ----- 
From: "John Miller" <jem at milleredp.com>
To: "'shop-talk'" <shop-talk at autox.team.net>
Sent: Thursday, February 04, 2010 10:15 AM
Subject: Re: [Shop-talk] An off shoot of the Toyota debacle.....


> A few automatics have the pump driven off the output side of the
> transmission, and I think some early ones actually had pumps on both input
> and output shafts.  This maintains lubrication flow within the
> transmission.

implies that there was only a pump on the output side - otherwise there 
would not have been a qualifier about "both input and output" ... which is 
why I was asking how that particular scenario worked.

Your thoughts?

Arvid


----- Original Message ----- 
From: "Mullen, Tim (IS)" <Tim.Mullen at ngc.com>
To: "shop-talk" <shop-talk at autox.team.net>
Sent: Thursday, February 04, 2010 3:10 PM
Subject: Re: [Shop-talk] An off shoot of the Toyota debacle.....


> Arvid Jedlicka Wrote:
>>
>> Just curious, if it is only on the output side how do you ever get it
>> to do anything?
>>
>>The pump would not be turning if the car is not moving and I can
>> only assume that if the pump is not turning there is no pressure
>> available to engage anything to get the car moving. I must be
>> missing something here ...
>
> The pump (in the transmission) is driven by the engine under normal
> circumstances.  Start the engine and it turns the input side of the
> transmission which turns the hydraulic pump.  With the pump turning,
> there is hydraulic pressure that allows you to "put it in gear".  The
> pump is driven from the input side of the transmission.
>
> If the car is moving and you shut off the engine, the transmission is
> still "locked in gear" (because it had hydraulic pressure) and the
> output side of the transmission can operate the hydraulic pump and
> continue to turn the engine over (the input and output of the
> transmission are locked together).  Once you put it in neutral (with the
> engine off), the input and output are no longer locked, and the input
> side stops turning - and the hydraulic pump stops pumping.  Now if you
> put it back in gear, it won't turn over the engine (or the pump) as
> there was no hydraulic pressure to keep things "locked".
>
> Tim Mullen
>
> Chantilly, VA