[DML] Re: Auto Trans behavior

["David Teitelbaum" <jtrealty@xxxxxxxxxxx>]

Although the pressure is a little high I wouldn't say it is too high.
Idealy you should lower it. The higher pressure is going to make it
shift hard and may cause more internal leakage of the seals possibly
even causing one to blow out. Higher is better than lower, low
pressure will cause the clutch packs to slip under load. I never tried
operating a trans without the shift computer although in theory with
shift hold you *should* be able to manualy shift from 1st to 2nd and
3rd by moving the gearshift. Be aware that there is no governor so it
may be possible to overspeed the trans in the lower gears. Maybe that
is why it won't go into 1st without being commanded by a solenoid. As
you can see the trans was designed with a "limp-home" mode. With
complete loss of power and shift computer you go to both solenoids off
which gets you 3rd gear. You may have trouble getting moving but it
does allow you manual shift hold and access to 3rd gear. The fluid
pressure is a really good indicator of the internal health of the
transmission. It tells you if the fluid pump can output at rating and
if there are any serious internal leaks. The pressure spec is for
Drive, the fluid paths are very different for Park, Reverse, and
Neutral so I would follow the Workshop Manual and adjust it for Drive.
The valve body is not very sophisticated in a Delorean, most of the
speed sensing and shifting is handled by the Governor-Computer
assembly (aka shift computer). Read the last sentance on G:01:02 left
side, bottom Para.  Again, there is no hydraulic governor in this
transmission to protect it.
David Teitelbaum
vin 10757 


--- In dmcnews@xxxxxxxxxxxxxxx, "Dave Swingle" <swingle@xxxx> wrote:
> After a couple of weeks off (Houston and family stuff) I'm back to
diagnosing the auto trans in my project car. As David T advised, I
acquired an oil pressure gauge and hooked it up. Service manual spec
is 8 bar (113 PSI) with the vacuum hose disconnected and in drive at
2500 RPM. 
> 
> The torque converter noise is still gone (as you remember last time,
I swapped torque converters with another trans and after about 5
minutes of running it cleared up. Still a bit of a mystery, but as
long as the noise is gone I'm happy). I've also exchanged the leaky
and possibly blocked cooling pipe. 
> 
>






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