Gary:
Just talked to Chuck Stoddard. He says that exceeding 300 deg F coming out
of the torque converter is what will cause death to the transmission. He
does not see a problem with the fluid temperature down to 0 deg F going into
the pan.
Guess that blows the theory I've previously heard espoused about the concern
for the fluid temperature going into the pan being too low. Therefore, I
guess that means it would be okay to route the transmission fluid cooler
lines from the radiator to a separate cooler and back to the pan.
Paul Bartz
From: Gary Miller [mailto:grizzly]
Sent: Wednesday, January 20, 1999 7:05 PM
Subject: Re: GMC: Fw: Trans Cooler, exhaust sytem
It is my understanding that as transmission temperatures go up, the life of
the fluid dramatically decreases and that 200 degrees is a temperature that
one would not want to exceed (for long). Ideally the temperature should
"cruise" around 175 degrees. What logic is there for not wanting an even
cooler fluid??? Does not the efficiency (lack of slip) of the transmission
increase as the temperature of the fluid drops to 100 degrees? Someone not
long ago posted a chart of temperature of fluid versus life of fluid. I
searched but couldn't find it. I have just installed Ragusa trany and final
drive pans, both with temperature probes but have not yet had a chance hit
the road and see what the temps actually are.
IIRC, you indicated that your transmission cooler lines were removed from
the radiator cooler and routed to the transmission cooler and back to the
transmission. At the Marion GMCMI convention, Chuck Stoddard in his
transmission seminar recommended that the transmission fluid needed to be in
the vicinity of 200 deg F going into the pan. Perhaps one of you can verify
my recollection????? It was also recommended that if a separate
transmission cooler is used, that it be plumbed in ahead of the input to the
radiator cooler so that the output fluid temperature would be raised/lowered
to the design temperature prior to going to the transmission. The
implication was that transmission fluid too cool did not allow the
transmission to operate most efficiently.
If I have your configuration right, do you know what the output temperature
of your transmission fluid is from your cooler?
Paul Bartz
From: srchrls [mailto:srchrls]
Sent: Monday, January 18, 1999 10:52 PM
Subject: GMC: Fw: Trans Cooler, exhaust sytem
Transmission cooler is located in the left front wheel well where the air
compressor was on the previous models. This is where the living area battery
is also located. Its a neat installation, I had Jim Rosenburgh in Sequim,
Wa. do the install. He has a 26' 77 GMC but I don't remember the model.
Just talked to Chuck Stoddard. He says that exceeding 300 deg F coming out
of the torque converter is what will cause death to the transmission. He
does not see a problem with the fluid temperature down to 0 deg F going into
the pan.
Guess that blows the theory I've previously heard espoused about the concern
for the fluid temperature going into the pan being too low. Therefore, I
guess that means it would be okay to route the transmission fluid cooler
lines from the radiator to a separate cooler and back to the pan.
Paul Bartz
From: Gary Miller [mailto:grizzly]
Sent: Wednesday, January 20, 1999 7:05 PM
Subject: Re: GMC: Fw: Trans Cooler, exhaust sytem
It is my understanding that as transmission temperatures go up, the life of
the fluid dramatically decreases and that 200 degrees is a temperature that
one would not want to exceed (for long). Ideally the temperature should
"cruise" around 175 degrees. What logic is there for not wanting an even
cooler fluid??? Does not the efficiency (lack of slip) of the transmission
increase as the temperature of the fluid drops to 100 degrees? Someone not
long ago posted a chart of temperature of fluid versus life of fluid. I
searched but couldn't find it. I have just installed Ragusa trany and final
drive pans, both with temperature probes but have not yet had a chance hit
the road and see what the temps actually are.
IIRC, you indicated that your transmission cooler lines were removed from
the radiator cooler and routed to the transmission cooler and back to the
transmission. At the Marion GMCMI convention, Chuck Stoddard in his
transmission seminar recommended that the transmission fluid needed to be in
the vicinity of 200 deg F going into the pan. Perhaps one of you can verify
my recollection????? It was also recommended that if a separate
transmission cooler is used, that it be plumbed in ahead of the input to the
radiator cooler so that the output fluid temperature would be raised/lowered
to the design temperature prior to going to the transmission. The
implication was that transmission fluid too cool did not allow the
transmission to operate most efficiently.
If I have your configuration right, do you know what the output temperature
of your transmission fluid is from your cooler?
Paul Bartz
From: srchrls [mailto:srchrls]
Sent: Monday, January 18, 1999 10:52 PM
Subject: GMC: Fw: Trans Cooler, exhaust sytem
Transmission cooler is located in the left front wheel well where the air
compressor was on the previous models. This is where the living area battery
is also located. Its a neat installation, I had Jim Rosenburgh in Sequim,
Wa. do the install. He has a 26' 77 GMC but I don't remember the model.
