Transmission leak from shifter shaft.

RF_Burns

RF_Burns

Super Moderator
Staff member
Sep 7, 2008
5,158
1,357
113
Ontario Canada
I have leak coming from the manual shifter shaft on my transmission. It been there for a while but has got worse after startup this spring.

Does anyone know the size of the O ring on the shifter shaft?

Has anyone replaced this O ring and have any advice to pass along?

Also, how long should it take for the torque converter to leak down? Seems like mine will leak down overnight (dipstick will read about 3" above full
cold before startup). Its about 10 years old and 25,000 miles since I replaced the tranny with a rebuild and new torque converter.

Thanks

--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
 
You can buy the seal at any auto parts store. It costs less than $3. Iirc I
had the pan off when I did mine. Others here will chime in on whether or
not the Pan needs to be off to do the seal. It was several years ago when I
did mine.

Sully
Bellevue wa

On Tue, May 7, 2019 at 8:45 AM Bruce Hislop via Gmclist <

> I have leak coming from the manual shifter shaft on my transmission. It
> been there for a while but has got worse after startup this spring.
>
> Does anyone know the size of the O ring on the shifter shaft?
>
> Has anyone replaced this O ring and have any advice to pass along?
>
> Also, how long should it take for the torque converter to leak down?
> Seems like mine will leak down overnight (dipstick will read about 3" above
> full
> cold before startup). Its about 10 years old and 25,000 miles since I
> replaced the tranny with a rebuild and new torque converter.
>
> Thanks
>
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Leak down of the trans varies by unit, as some takes few days and some
overnight.
I will get the size on the O ring later.

On Tue, May 7, 2019 at 8:45 AM Bruce Hislop via Gmclist <

> I have leak coming from the manual shifter shaft on my transmission. It
> been there for a while but has got worse after startup this spring.
>
> Does anyone know the size of the O ring on the shifter shaft?
>
> Has anyone replaced this O ring and have any advice to pass along?
>
> Also, how long should it take for the torque converter to leak down?
> Seems like mine will leak down overnight (dipstick will read about 3" above
> full
> cold before startup). Its about 10 years old and 25,000 miles since I
> replaced the tranny with a rebuild and new torque converter.
>
> Thanks
>
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
Pan must come off as it is held from the inside.
Still waiting for the data on the O ring size.

On Tue, May 7, 2019 at 1:47 PM Todd Sullivan via Gmclist <

> You can buy the seal at any auto parts store. It costs less than $3. Iirc I
> had the pan off when I did mine. Others here will chime in on whether or
> not the Pan needs to be off to do the seal. It was several years ago when I
> did mine.
>
> Sully
> Bellevue wa
>
> On Tue, May 7, 2019 at 8:45 AM Bruce Hislop via Gmclist <

>
> > I have leak coming from the manual shifter shaft on my transmission. It
> > been there for a while but has got worse after startup this spring.
> >
> > Does anyone know the size of the O ring on the shifter shaft?
> >
> > Has anyone replaced this O ring and have any advice to pass along?
> >
> > Also, how long should it take for the torque converter to leak down?
> > Seems like mine will leak down overnight (dipstick will read about 3"
> above
> > full
> > cold before startup). Its about 10 years old and 25,000 miles since I
> > replaced the tranny with a rebuild and new torque converter.
> >
> > Thanks
> >
> > --
> > Bruce Hislop
> > ON Canada
> > 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> > http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> > My Staff says I never listen to them, or something like that
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
I went to the local auto parts stores today. They only have listings for complete overhaul kits. So then I went to several transmission rebuilders.
None had ever seen a HT425 and knew nothing about them. One showed me the seal for a th400, but it is like a small version of an axle seal and not an
O ring.

JimK, if you could get me the dimensions of the O-ring on the shifter shaft, that would be great!

Thanks

--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
 
I did, he will send when he gets home

On Wed, May 8, 2019 at 6:52 AM Johnny Bridges via Gmclist <

> Manny Travao is Your Friend. Give him a shout ans ask what size o-ring.
> http://www.mannystransmission.com/index.html
>
>
> --johnny
> --
> Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
> Braselton, Ga.
> I forgive them all, save those who hurt the dogs. They must answer to me
> in hell
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
A012
9.25x1.78

> I did, he will send when he gets home
>
> On Wed, May 8, 2019 at 6:52 AM Johnny Bridges via Gmclist <

>
>> Manny Travao is Your Friend. Give him a shout ans ask what size o-ring.
>> http://www.mannystransmission.com/index.html
>>
>>
>> --johnny
>> --
>> Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
>> Braselton, Ga.
>> I forgive them all, save those who hurt the dogs. They must answer to me
>> in hell
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk
> http://www.appliedgmc.com
> 1-800-752-7502
>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
If you have problem finding one, I will send it to you N/C.

On Thu, May 9, 2019 at 4:02 AM Bruce Hislop via Gmclist <

> Thanks Jim!
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
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