Cooked my tranny

> Larry-
>
> I found photos of yours on the gmcphoto site. So I am not in need of photos.

Jon, those are old photos from the last trans rebuild. Using the same fan but different cooler that I got from Steve. I'll take a picture of it
tomorrow and delete the old photos from the photo site.
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
Jon,

You have stated that the recovered fluid did not evidence being burned. (Did I read that correctly?)

If that is the case, then "cooked" is not the correct diagnosis. When you get the postmortem completed, I and I am sure others would like to know
what the real and final issue was. It may save someone else a failure in the future.

Thanks

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
 
Matt-

it got hot enough to burp out the vent.

I am running mobile 1 synthetic ATF by the guidance of the last re-builder. when you pull the dipstick, and rub it on a white towel, it looks pink
still.

when we started draining it, 3 of us got our fingers dirty and were trying to smell it, and it did not have a bad smell.

then we popped the cover off and let the rest drain, and that is when the nose could pick up the "stink". it was burnt, and if you look carefully
now at the mobile1 at a larger volume then just the little bit on the white rag, it actually turns a bit of a purple color.

who knows if we will ever get to the root cause. The nail in it's coffin is it got overheated on that mountain pass. I will talk to steve
turnquist a little more about what we want to try to save out of my old tranny for future parts, and may end up taking it apart. but as it stands,
he has two unrelated cores to rebuild into a good tranny, that both came out of coaches that were operational when transmission was removed.

#1 goal right now is to get my coach back together, then will start looking into more of what happened with that other tranny.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
> Matt-
> it got hot enough to burp out the vent.
> I am running mobile 1 synthetic ATF by the guidance of the last re-builder. when you pull the dipstick, and rub it on a white towel, it looks
> pink still.
> when we started draining it, 3 of us got our fingers dirty and were trying to smell it, and it did not have a bad smell.
> then we popped the cover off and let the rest drain, and that is when the nose could pick up the "stink". it was burnt, and if you look
> carefully now at the mobile1 at a larger volume then just the little bit on the white rag, it actually turns a bit of a purple color.
> who knows if we will ever get to the root cause. The nail in it's coffin is it got overheated on that mountain pass. I will talk to steve
> turnquist a little more about what we want to try to save out of my old tranny for future parts, and may end up taking it apart. but as it
> stands, he has two unrelated cores to rebuild into a good tranny, that both came out of coaches that were operational when transmission was
> removed.
> #1 goal right now is to get my coach back together, then will start looking into more of what happened with that other tranny.

Jon,

Thank you for the in depth response. My experience with Mobil 1 AFT is limited. I would not have expected it to go bad with heat as it seems to have.


It sounds like you have a good plan and will be back underway in good time and that is about all you can hope for in such cases.

I do look forward to the complete diagnosis.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
 
Jon,
Lucy will put the fittings in the mail tomorrow. Hold on too the ones you don't use and get them back to me.

--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
Larry-

Thank you. those seemed to work, but copper washer was hard to find. I had to drill one out. I will get some more copper washer's made up and get
you the rest that are left.

Update - GMC club helped provide a good core for rebuild- I picked that up from Steve Turnquist. spent the rest of the afternoon finding some
lines and such to get the tranny cooler plumbed up, and bought 4 gallons of ATF.

We installed the transmission later Saturday afternoon. I was surprised at how tight of a fit it was. My experience was to get the bolts just barey
started on the final drive, then level and adjust the engine to transmission, and it seemed to go into place. Getting the upper tranny to mount
bolts was also a little bit of a careful manipulation of the transmission. Work was all done on a lift, I thank my lucky stars I did not have to do
this in my driveway or on the road. Kudo's to those that have done that.

Saturday we plumbed in the lines, and installed the tranny cooler. then unfortunatly the test drive showed a leaking problem. After many
cleanings and checks, it is determined it is leaking between the final drive and transmisison. I did not think we had issues with that gasket on
install, but it is not the easiest thing to see. The other thing I am questioning as I have never had this problem when installing final drives and
such in the past, was the gasket we used. It was a gasket that came with the transmission rebuild gasket kit. I don't know the maker of the
gasket. I just know in all the other 3-5 that i have done over the years, I have always installed a fel-pro gasket. Just strange, but we got the
leaking to slow, but not stop by tightening up the bolts. (they were torqued- but now they are over torque and still having leak- just less).

so back to stupid job I have, and need to find some time to go pull the final drive and install a new gasket and hopefully that will take care of the
leak.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
Final drive to transmission is a regal bitch to do without screwing up that
duplex seal. Then it leaks out of the weep hole. I always support the
engine from above, and lower the transmission and final drive as an
assembly. Install it the reverse. Mate them on the bench with good
lighting. Screwed up a couple of them trying to just do the transmission. I
absolutely hate doing stuff over. Ruins my whole day.
Jim Hupy
Salem, Oregon

On Mon, Aug 3, 2020, 10:34 AM Jon Roche via Gmclist
wrote:

> Larry-
>
> Thank you. those seemed to work, but copper washer was hard to find. I
> had to drill one out. I will get some more copper washer's made up and
> get
> you the rest that are left.
>
>
> Update - GMC club helped provide a good core for rebuild- I picked that
> up from Steve Turnquist. spent the rest of the afternoon finding some
> lines and such to get the tranny cooler plumbed up, and bought 4 gallons
> of ATF.
>
> We installed the transmission later Saturday afternoon. I was surprised
> at how tight of a fit it was. My experience was to get the bolts just barey
> started on the final drive, then level and adjust the engine to
> transmission, and it seemed to go into place. Getting the upper tranny to
> mount
> bolts was also a little bit of a careful manipulation of the
> transmission. Work was all done on a lift, I thank my lucky stars I did
> not have to do
> this in my driveway or on the road. Kudo's to those that have done that.
>
> Saturday we plumbed in the lines, and installed the tranny cooler. then
> unfortunatly the test drive showed a leaking problem. After many
> cleanings and checks, it is determined it is leaking between the final
> drive and transmisison. I did not think we had issues with that gasket on
> install, but it is not the easiest thing to see. The other thing I am
> questioning as I have never had this problem when installing final drives
> and
> such in the past, was the gasket we used. It was a gasket that came
> with the transmission rebuild gasket kit. I don't know the maker of the
> gasket. I just know in all the other 3-5 that i have done over the
> years, I have always installed a fel-pro gasket. Just strange, but we got
> the
> leaking to slow, but not stop by tightening up the bolts. (they were
> torqued- but now they are over torque and still having leak- just less).
>
> so back to stupid job I have, and need to find some time to go pull the
> final drive and install a new gasket and hopefully that will take care of
> the
> leak.
>
>
>
>
>
> --
> Jon Roche
> 75 palm beach
> EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Jon,

I've had experiences similar to yours -- good 'n' bad. The device shown
here DOES work:
http://www.gmcmhphotos.com/photos/th425-lifting-device/p45166-the-final-drive-gasket-protection-guard-prevents-damage.html

It's not obvious in the photo, but the two studs at the bottom are headless
& screwdriver slotted so they can be removed after the gasket guards are
removed and the other bolts cinched down.

Ken H.

On Mon, Aug 3, 2020 at 1:34 PM Jon Roche via Gmclist <

> Larry-
>
> Thank you. those seemed to work, but copper washer was hard to find. I
> had to drill one out. I will get some more copper washer's made up and
> get
> you the rest that are left.
>
>
> Update - GMC club helped provide a good core for rebuild- I picked that
> up from Steve Turnquist. spent the rest of the afternoon finding some
> lines and such to get the tranny cooler plumbed up, and bought 4 gallons
> of ATF.
>
> We installed the transmission later Saturday afternoon. I was surprised
> at how tight of a fit it was. My experience was to get the bolts just barey
> started on the final drive, then level and adjust the engine to
> transmission, and it seemed to go into place. Getting the upper tranny to
> mount
> bolts was also a little bit of a careful manipulation of the
> transmission. Work was all done on a lift, I thank my lucky stars I did
> not have to do
> this in my driveway or on the road. Kudo's to those that have done that.
>
> Saturday we plumbed in the lines, and installed the tranny cooler. then
> unfortunatly the test drive showed a leaking problem. After many
> cleanings and checks, it is determined it is leaking between the final
> drive and transmisison. I did not think we had issues with that gasket on
> install, but it is not the easiest thing to see. The other thing I am
> questioning as I have never had this problem when installing final drives
> and
> such in the past, was the gasket we used. It was a gasket that came
> with the transmission rebuild gasket kit. I don't know the maker of the
> gasket. I just know in all the other 3-5 that i have done over the
> years, I have always installed a fel-pro gasket. Just strange, but we got
> the
> leaking to slow, but not stop by tightening up the bolts. (they were
> torqued- but now they are over torque and still having leak- just less).
>
> so back to stupid job I have, and need to find some time to go pull the
> final drive and install a new gasket and hopefully that will take care of
> the
> leak.
>
>
>
>
>
> --
> Jon Roche
> 75 palm beach
> EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
thanks Ken- I have one of your lifting devices I bought at amana from you and it works wonderful. I usually buy two gaskets just to be sure I am
ready if I mess one up.

verdict is in now that the final drive is sitting on the bench. amateur hour and in maybe too much of a rush, there was a 3" chuck of old gasket
still on the final drive. That sure will cause a bad seal/leak!!! I have no idea how that was missed, but I suppose it was hidden in that upper
corner. Small mistake caused a bunch of extra time and work, we should know better.

Heading down later today to re-install the the final drive, and hopefully drive my coach home!



--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
UPdate-

went down last friday, re-installed the final drive this time without that 3" piece of old gasket stuck. All is well, no leaks.

drove it home about 1.5 hours and it ran flawless again. It did seem to have some better off the line feel and did not seem to labor as much as I
remember towing my car, but that could all be in my head.

I installed a fan on the transmission cooler, and spent this week cleaning off the road trip grime. I also now have my transmission gauge wired up,
and I am heading about 113 miles to the East today with the family for a weekend of camping.

I hope we can do an autopsy of my cooked tranny later this month. for any lurkers- get involved with your club. This really would of been a super
bad experience if I did not have the assistance of the GMC community. there is so much help out there, you have no idea how this can make owning a
gmc so much more rewarding. knowing these people when you are not in need of help is even more rewarding.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
> UPdate-
>
> went down last friday, re-installed the final drive this time without that 3" piece of old gasket stuck. All is well, no leaks.
>
> drove it home about 1.5 hours and it ran flawless again. It did seem to have some better off the line feel and did not seem to labor as much as
> I remember towing my car, but that could all be in my head.
>
> I installed a fan on the transmission cooler, and spent this week cleaning off the road trip grime. I also now have my transmission gauge wired
> up, and I am heading about 113 miles to the East today with the family for a weekend of camping.
>
> I hope we can do an autopsy of my cooked tranny later this month. for any lurkers- get involved with your club. This really would of been a
> super bad experience if I did not have the assistance of the GMC community. there is so much help out there, you have no idea how this can make
> owning a gmc so much more rewarding. knowing these people when you are not in need of help is even more rewarding.

Jon,

Did I send you 4 or more of the brass 3/8 to transmission line adaptors? If you have any left, bring them with you to Midwest Classics. Got another
guy that needs a set.
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
Glad to hear it Jon. It's good that you are up and running.

You're right about the club/community support. It is invaluable, especially in times of trouble.

A year or so before I spun a bearing in my 455, I had purchased a bottom end kit from Steve Ferguson, that he was selling for another GMCer who had
taken it as a warranty item from Mondello. I didn't know if I would need it at the time, but it came in handy to have a new crankshaft and a set of
rods when I needed them I still have the pistons. they are flat tops and too high compression for our application. If anyone wants them, I will
make them a good deal.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member
 
Glad to hear your coach is up and running!!

Post up some pics of your trans cooler install Jon if you can as i'd im sure their are some, myself included, that would love to see it.
--
Rich Mondor,

Brockville, ON

77 Hughes 2600
 
I am not yet happy with the cooler install.

the 3/8 in metal lines, are great, and they are bent down and hug the top of the transmission to the final drive. I have them wrapped in some heat
wrap too.

made a bracket on the end of the final drive bolt to secure them, similar to how the oil lines are secured on the passenger side. The just like the
oil lines on passenger side, the tranny cooler lines transition form hard line to AN fittings and hose and go around to front of the transmission.

The darelle cooler I bought I think is too small. it is a stacked plate cooler, 20000 BTU, but it has a fan so they do not rate the cooler as a combo
with the fan. I do not like how the cooler is built, as for an install it does not work as well, because not setup to where I Can install it easily
backwards so it sucks air. instead the fan is in front, and reversing the wires makes it blow toward the engine, but you can tell it does air flow
as well, as when it is sucking across the cooler.

I am going to buy a tru-cooler 40,000 btu tranny cooler and swap that in, and probably make my own fan. that cooler is twice the size as the
darele.

last trip I took not-towing, tranny pan temp stayed under 150. Around town driving it seemed to jump to 160-170 max. that is basically our town
makes you stop every block, so you are constantly accelerating from a stop. the fan seemed to not make an immediate noticeable drop in temps, but I
would not expect to be able to notice that.

I checked the hose temps with my IR gun when I got home after towing my car home. The tranny cooler had a drop from inlet to outlet. I did not
write the numbers down, but they were well under 180, so I was not concerned further.

I will post once I have it how I want it to be. I am towing this weekend so I will be curious what the temps do.
--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
> I am not yet happy with the cooler install.
>
> the 3/8 in metal lines, are great, and they are bent down and hug the top of the transmission to the final drive. I have them wrapped in some
> heat wrap too.
>
> made a bracket on the end of the final drive bolt to secure them, similar to how the oil lines are secured on the passenger side. The just like
> the oil lines on passenger side, the tranny cooler lines transition form hard line to AN fittings and hose and go around to front of the
> transmission.
>
>
> The darelle cooler I bought I think is too small. it is a stacked plate cooler, 20000 BTU, but it has a fan so they do not rate the cooler as a
> combo with the fan. I do not like how the cooler is built, as for an install it does not work as well, because not setup to where I Can install it
> easily backwards so it sucks air. instead the fan is in front, and reversing the wires makes it blow toward the engine, but you can tell it does
> air flow as well, as when it is sucking across the cooler.
>
> I am going to buy a tru-cooler 40,000 GVW tranny cooler and swap that in, and probably make my own fan. that cooler is twice the size as the
> darele.
>
>
> last trip I took not-towing, tranny pan temp stayed under 150. Around town driving it seemed to jump to 160-170 max. that is basically our
> town makes you stop every block, so you are constantly accelerating from a stop. the fan seemed to not make an immediate noticeable drop in temps,
> but I would not expect to be able to notice that.
>
> I checked the hose temps with my IR gun when I got home after towing my car home. The tranny cooler had a drop from inlet to outlet. I did
> not write the numbers down, but they were well under 180, so I was not concerned further.
>
>
>
> I will post once I have it how I want it to be. I am towing this weekend so I will be curious what the temps do.

Your radiator, is it the newer aluminum or old style copper/brass? I ask, because you could always have the core desoldered from the passenger side
tank, remove and replace the trans cooler, and soldered back together. Maybe??

I ran with this setup and no trans radiator cooler for a couple of years and rarely saw temps above 170*. Trans cooler on left, engine oil on right.
http://www.gmcmhphotos.com/photos/transmission-cooler/p67447-transmission-cooler.html
http://www.gmcmhphotos.com/photos/transmission-cooler/p67446-transmission-and-oil-coolers.html

--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
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