[v12-engine] GM400 Spitting out tranny fluid

Gentlemen

Lady Chatterley’s GM400 has decided to play up in the past few days. After a
cold start, having driven half a mile or so, she spits out the transmission
dip-stick about half an inch and spews the Dexron all over the underbonnet
and into the vee etc. depositing oil onto the exhaust and other hot bits and
making an indecent cloud of smelly smoke.

I cleaned off the oil the first time and blamed myself for not putting the
dip-stick back snugly. It’s happend twice since then again, however. Is
there supposed to be pressure up the tube?

Another symptom that has accompanied this is akin to low fluid - take a
corner (right hand) and the revs climb but the drive seems to lose about 50%
of its oomph until the car is travelling straight again…back off on the
throttle and it kicks-in again and goes as normal.

Another oddity is that, after standing for a day or two (week-end), if the
car is started and left to idle for a minute or so before selecting gear, it
takes a bit of revving to get any action out of the box…almost as if the
fluid has drained from the turbine and needs to be pumped in again (not an
expert view…just my attempt at a description of events)

I’ve checked the fluid (it’s always checked weekly anyhow) and it is to spec
and up to the correct level on the dip stick.

The box was re-built in January 99 after being wrecked during the infamous
“service by the authorised agents”. A recon torque converter was fitted at
the time.

There are no noises such as I previously learnt indicated a torque converter
going belly-up and no other unusual noises when it works well.

Any ideas as to what is starting to go wrong or has already gone wrong?

Thanks in advance

Mark Young
Johannesburg, South Africa
1983 Daimler Double Six Series III V12 HE Van Den Plas 248 000km
1972 Series I 4.2 XJ6 SWB restoration project (half done now Christmas is
the target)

“Africa - Not a continent for sissies!”

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she spits out the transmission

dip-stick about half an inch and spews the Dexron all over the underbonnet
and into the vee etc. > Is
there supposed to be pressure up the tube?

Check and clean your trans vent tube…
Cheers,
Jeb Boyd
V-12 Engine List Admin
British Car Junkie
@J_L_Autoworks

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http://www.jag-lovers.org/cgi-bin/majordomoFrom: “Mark D Young”

You might have more than one thing going on there, since the tranny was
rebuilt. However, there is a pressure relief vent on the case. If it is
plugged, that would account for the dipstick unseating. If the vent is
plugged from the outside, you can fix it easily. If it is plugged from
the inside your tranny might have puked something, and that might relate
to the other problems.

JohnOn Fri, 4 Aug 2000, Mark D Young wrote:

Gentlemen

Lady Chatterley’s GM400 has decided to play up in the past few days. After a
cold start, having driven half a mile or so, she spits out the transmission
dip-stick about half an inch and spews the Dexron all over the underbonnet

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Lady Chatterley’s GM400 has decided to play up in the past
few days. After a
cold start, having driven half a mile or so, she spits out
the transmission
dip-stick about half an inch and spews the Dexron all over
the underbonnet
and into the vee etc. depositing oil onto the exhaust and
other hot bits and
making an indecent cloud of smelly smoke.

Another oddity is that, after standing for a day or two
(week-end), if the
car is started and left to idle for a minute or so before
selecting gear, it
takes a bit of revving to get any action out of the
box

That’s strange. I’ve checked the ROM, and Ron Sessions book on how to
completely tear a 400 to bits and rebuild it, and there is nothing that
mentions the dipstick blowing out as a problem or symptom. It infers that
there is a build-up of pressure in the transmission case, which there
shouldn’t ought to be - there is a vent pipe at the top of the case that is
supposed to prevent that happening. Maybe the rebuilders left a chunk of
garbage in the case, or a piece of friction material has parted company and
blocked a passage somewhere.

Craig

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