TRNW-2: VW O9G mysterious leak

[Steve Everett]

 I thought about that, but I can't really see how ,  there are two dowel
pins that line the case half up, originally built by someone else, and then
I put the second bellhousing half on it, I've never seen anything about a
torque procedure on those units ?  if I've overlooked it and anyone knows
about one ?  please enlighten me !

    Steve

On Tue, Dec 16, 2025 at 3:16 PM Chris and Cathy Kershaw <
kershawservicesllc at gmail.com> wrote:

> Right next to that bolt maybe a torque issue? I remember cracking the side
> cover on a 4t65 at the bottom by the torx bolts, proper torque and sequence
> would prevent it.
>
> On Tue, Dec 16, 2025 at 3:12 PM Steve Everett via trnw2 <trnw2 at trnw.net>
> wrote:
>
>>  We put dye in the fluid and finally verified where its leaking from, the
>> crease where the arrow points,  there apparently is a crack there , can't
>> see it with your naked eye, but the dye was seeping from that crack, same
>> place the other bellhousing was apparently leaking from,  we're going to
>> see if we can get it tig welded by a machine shop locally
>>
>>     there is a pressure passageway on the other side of that crease,
>> that is fed by a passageway on the pump body , I've since discovered the
>> valvebody was replaced when it was originally built, there is more than one
>> valvebody for these units,  I don't know if there is a difference in
>> pressures or variations that might explain this ?  I know there are a
>> couple of holes different between VB's relating to lube supply ?
>>
>>    Steve
>>
>> On Tue, Dec 16, 2025 at 2:48 PM Donald Day <trnsmaster at verizon.net>
>> wrote:
>>
>>> If bell is porous clean good then coat with epoxy
>>>
>>>
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>>> On Tuesday, December 16, 2025, 10:24 AM, Steve Everett via trnw2 <
>>> trnw2 at trnw.net> wrote:
>>>
>>>   I have an 09 Jetta with a O9G , originally built at another shop, 2
>>> months after being built it had a small leak from inside the bellhousing,
>>> small enough that sitting running after 5 minutes there will be one drop at
>>> the inspection hole at the bottom of the bellhousing,  when you look up
>>> inside that hole the fluid seems to be seeping from the right side up
>>> inside the bell,  we pulled the unit, and fluid appeared to be coming from
>>> around the uppermost bolt on the right side,  (red dot in picture
>>> attached)  I removed the bellhousing, cleaned everything, resealed the bell
>>> and used silicone on all the bolts,  reinstalled unit and still had the
>>> leak,  pulled again,  this time I thought maybe the case was porous in the
>>> are above and to the left of the bolt, as fluid appeared to be in that
>>> area,  I cleaned everything with brake clean, coated that area with JB
>>> weld, resealed the same bolt again, installed a different converter,,,
>>> installed unit,    same leak again,
>>>        took a week or so for us to find another unit,  removed
>>> bellhousing from core unit, cleaned and resealed everything related to the
>>> different bellhousing,   reinstalled,   still have same leak,
>>>
>>>   Different bellhousing, changed attaching bolts the last time around,
>>> using ultra grey silicone to seal everything,  plenty of silicone on all
>>> the bolts, changed converters once, ( fluid is not all over inside of
>>> bellhousing , only on right side, so I don't believe its converter related)
>>>
>>>   only explanation would be two different bellhousing being porous in
>>> same area ?    in the picture attached the fluid originates in the area
>>> where the red dot is
>>>
>>>  Anyone ever seen something like this ?
>>>
>>>    Steve
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