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Transmission Leak [message #322909] Tue, 29 August 2017 08:03 Go to next message
tgeiger is currently offline  tgeiger   United States
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A little update on the shifting issue I had. Had replaced the modulator and it did not seem to improve the shifting up and down from 3rd to 2nd so I took it into the truck and RV service center near me and had a transmission service done to it and now everything is back to normal, so it had to have been an issue with filter or level of fluid as well. It is a bit difficult to get a good reading on fluid level on this thing. Anyhow, glad it is back to shifting smoothly. I did notice that the transmission pan seems to be leaking a whole bunch more. Leaves a good square spot on the driveway. Is this something that is typical when a service is done, or did my service place muck something up?

Tom
76 Eleganza 2
Kansas City, Mo

[Updated on: Tue, 29 August 2017 08:04]

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Re: Transmission Leak [message #322910 is a reply to message #322909] Tue, 29 August 2017 08:10 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
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Perhaps they used an air impact on the pan bolts and dimpled the pan at each bolt hole. That reduces clamping on areas between bolt holes. You have to remove and set upside down on flat hard surface to see. Then carefully hammer the dimples back till granite smooth. Torque specs are important.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: Transmission Leak [message #322912 is a reply to message #322909] Tue, 29 August 2017 08:33 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
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Have seen about a 1/2 dozen pans come loose in my life time after some mechanic had the pan off. I can't blame the mechanic as one of those was a tranny pan inhad off myself. The bolts torque is low and i think the gasket and heat cycles can make the bolts come loose.

So i always check transmission pan bolts a few times after they have been removed and replaced now.

However the other problem our old coaches have is torque converter leak down. When parked the fluid leaks out of the torque converter and over fills the pan, causing it to leave a mark on ground when parked.



Jon Roche 75 palm beach St. Cloud, MN http://lqqkatjon.blogspot.com/
Re: Transmission Leak [message #322914 is a reply to message #322909] Tue, 29 August 2017 08:44 Go to previous messageGo to next message
tgeiger is currently offline  tgeiger   United States
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Ok guys, will check on those items. Is there any special extra thick gasket that would seal things up better like we had for my Thorley headers I got from Jim K? Or is the stock gasket out of the service kit all we have?
Re: Transmission Leak [message #322917 is a reply to message #322909] Tue, 29 August 2017 09:04 Go to previous messageGo to next message
77Royale   United States
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Curious to know if anyone has had better sealing luck with the cork or rubberized gaskets?

77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson carb and dizzy. Mid Michigan
Re: Transmission Leak [message #322938 is a reply to message #322917] Tue, 29 August 2017 11:37 Go to previous messageGo to next message
roy1 is currently offline  roy1   United States
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Keep in mind some of the transmission bolts protrude into the fluid so they can leak around the bolt. In this case it would help to use a bolt with a built in washer and a little gasket with sealer. Just look real close at each bolt to see if it is the source of a leak.

Roy Keen Minden,NV 76 X Glenbrook
Re: [GMCnet] Transmission Leak [message #322955 is a reply to message #322938] Tue, 29 August 2017 15:50 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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I do not know of a thicker pan gasket.
Just straighten the pan lip by using a ball pene hammer.
Also a cast Aluminum pan can help seal better,

On Tue, Aug 29, 2017 at 9:37 AM, roy keen wrote:

> Keep in mind some of the transmission bolts protrude into the fluid so
> they can leak around the bolt. In this case it would help to use a bolt
> with a
> built in washer and a little gasket with sealer. Just look real close at
> each bolt to see if it is the source of a leak.
> --
> Roy Keen
> Minden,NV
> 76 X Glenbrook
>
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Re: [GMCnet] Transmission Leak [message #322959 is a reply to message #322909] Tue, 29 August 2017 16:36 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Tom,

Suggest you:

- remove the pan and check the flange to see if there are dings around the bolt holes

- remove them with a two ball peen hammers - put one in the bolt hole and hit the flat face with the other

- replace the cork gasket - cork is OK

- replace the bolts with self locking flange bolts http://tinyurl.com/y99jnfgk

- coat the pan flange with Permatex Aviation Form-A-Gasket No. 3 Sealant http://tinyurl.com/y7zmy4rw

- put the cork gasket on the pan flange and coat it with Permatex Aviation Form-A-Gasket No. 3 Sealant

- install the pan on the transmission case and hand tighten the bolts lightly

- torque the bolts to 12 ft lb

- service the transmission

- go for a test drive

- have a beer when you get home to celebrate fixing the problem

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces-AT-list-DOT-gmcnet-DOT-org] On Behalf Of tom geiger
Sent: Tuesday, August 29, 2017 11:03 PM
To: gmclist-AT-list-DOT-gmcnet-DOT-org
Subject: [GMCnet] Transmission Leak

A little update on the shifting issue I had. Had replaced the modulator and it did not seem to improve the shifting up and down
from 3rd to 2nd so I
took it into the truck and RV service center near me and had a transmission service done to it and now everything is back to normal,
so it had to
have been an issue with filter or level of fluid as well. It is a bit difficult to get a good reading on fluid level on this thing.
Anyhow, glad it
is back to shifting smoothly. I did notice that the transmission pan seems to be leaking a whole bunch more. Leaves a good square
spot on the
driveway. Is this something this is typical when a service is done, or did my service place muck something up?

Tom
76 Eleganza 2
Kansas City, Mo

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: Transmission Leak [message #322968 is a reply to message #322909] Tue, 29 August 2017 19:04 Go to previous messageGo to next message
tgeiger is currently offline  tgeiger   United States
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Ah, well there is my problem Rob. My sequence of events is backwards when I do work on Sugar Pie. I start with the beer and then go on to the next steps!
Re: [GMCnet] Transmission Leak [message #322969 is a reply to message #322968] Tue, 29 August 2017 19:09 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Nothing wrong with that as long as you don't wind up looking through beer goggles! ;-)

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808

-----Original Message-----
From: Gmclist [mailto:gmclist-bounces-AT-list-DOT-gmcnet-DOT-org] On Behalf Of tom geiger
Sent: Wednesday, August 30, 2017 10:04 AM
To: gmclist-AT-list-DOT-gmcnet-DOT-org
Subject: Re: [GMCnet] Transmission Leak

Ah, well there is my problem Rob. My sequence of events is backwards when I do work on Sugar Pie. I start with the beer and then go
on to the next
steps!

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: Transmission Leak [message #322973 is a reply to message #322909] Tue, 29 August 2017 20:16 Go to previous messageGo to next message
Carl S. is currently online  Carl S.   United States
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In some cases, if the pan bolts are over tightened, the gasket can squeeze out (or in, which is harder to see) causing a leak. I had this happen with a Gary Rockwell pan that I never could get to seal right. When I traded it in to Jim K for a Ragussa pan, he sent me a FelPro gasket that had the perfect size holes in it, and sealed really well.

I recently did this job again, and used the gasket that came in the filter kit (also from Jim K. and it sealed perfectly as well. I prefer to not use any type of gasket sealer if I can get away with it, due to the clean-up issues the next time. I did follow the manual torque spec of 12 foot pounds and it is nie and tight with no leaks.


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
Re: Transmission Leak [message #326328 is a reply to message #322909] Sat, 25 November 2017 13:28 Go to previous messageGo to next message
tgeiger is currently offline  tgeiger   United States
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Ok, so now I'm in it. Doing the transmission pan thing. Had taken it yo a local truck and RV service center and that was not sucessfull after their third attempt, so I'm just going to follow your all good direction and do it myself. The dang thing leaked like a sive after their third attempt. So here I go. Got the pan off and I definstly see some dippling at the bolt holes. Going to try to hammer those out. I do see those locations on the back flange where the lip edge was cut out for some reason. Not much edge there to seal up. Going to just isr a rubber composite gasket to see if it will sral. Keep my fingers crossed.

[Updated on: Sat, 25 November 2017 13:30]

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Re: [GMCnet] Transmission Leak [message #326329 is a reply to message #326328] Sat, 25 November 2017 14:12 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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When working with the stock metal pan, one must turn the pan upside down
and have a steel narrow bar under the bolt holes and use a ball peen hammer
and level it out.
Not a bad Idea to use some sealent aroung the gasket holes and never over
tighten.
Yo might want to check around the holes that leak as there might be a
remote possibility of a crack


On Sat, Nov 25, 2017 at 11:28 AM, tom geiger wrote:

> Ok, so now I'm in it. Doing the transmission pan thing. Had taken it yo a
> local truck and TV setvice center and that was not sucessfull after their
> third attempt, so I'm just going to follow your all good direction and do
> it myself. The dsng thing leaked like a sive after their third attempt. So
> here I go. Got the pan off and I definstly see some dippling at the bolt
> holes. Going to try to hammer those out. I do see those locations on the
> back
> flange where the lip edge was cut out for some reason. Not much edge there
> to seal up. Going to just isr a rubber composite gasket to see if it will
> sral. Keep my fingers crossed.
>
> _______________________________________________
> 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-AT-appliedairfilters-DOT-com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk-AT-appliedairfilters-DOT-com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] Transmission Leak [message #326330 is a reply to message #326329] Sat, 25 November 2017 15:35 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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When the fluid level increases as the torque converter bleed down, the filler tube will leak past the existing O ring and drain fluid after a week or two. We put some sealent on the O ring and tube after wiping it clean and that stops the leak.

Quote:

Transmission Leak Tue, 29 August 2017 06:03
tgeiger
Karma:
A little update on the shifting issue I had. Had replaced the modulator and it did not seem to improve the shifting up and down from 3rd to 2nd so I took it into the truck and RV service center near me and had a transmission service done to it and now everything is back to normal, so it had to have been an issue with filter or level of fluid as well. It is a bit difficult to get a good reading on fluid level on this thing. Anyhow, glad it is back to shifting smoothly. I did notice that the transmission pan seems to be leaking a whole bunch more. Leaves a good square spot on the driveway. Is this something that is typical when a service is done, or did my service place muck something up?

Tom
76 Eleganza 2
Kansas City, Mo


Jim Kanomata
Applied/GMC
jimk-AT-appliedairfilters-DOT-com
www.appliedgmc.com
1-800-752-7502
Re: Transmission Leak [message #326331 is a reply to message #322909] Sat, 25 November 2017 16:07 Go to previous messageGo to next message
Larry is currently offline  Larry   United States
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I chased a leak for over a year. Here is what I found. Open the engine hatch and look down at the cooler lines going into the transmission. If you are seeing fluid laying in that trough between the back chain cover the engine block, the fluid may be coming from a bolt hole that is located near the inner trans cooler line. Not all 425 transmissions have this. Check out this link if you see trans fluid in that trough.

http://www.gmcmhphotos.com/photos/transmission-leak/p63991-odd-trans-leak.html

If no fluid in the trough, don't bother looking at this.

HTH



Larry Smile
78 Royale w/500 Caddy
Menomonie, WI.
Re: Transmission Leak [message #326344 is a reply to message #322909] Sun, 26 November 2017 08:30 Go to previous messageGo to next message
tgeiger is currently offline  tgeiger   United States
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Crap guys, sorry. I need to learn how to copy and paste correctly on my phone. Was just trying to past the proceedure Bob posted up.

Jim, when you talk about putting some sealant around the bolts. Are you saying to do this on both sides of the gasket at the bolt locations or are you saying dab a glob on the hole before the bolt goes in?
Re: Transmission Leak [message #326347 is a reply to message #322909] Sun, 26 November 2017 10:29 Go to previous messageGo to next message
tgeiger is currently offline  tgeiger   United States
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Jim, when you say take some gasket seal and dab it at the bolts, are you sayinging I do a circle around the bolt holes to tack the gasket and flange together or just glob some at the bolt hole before the bolt goes in?
Re: [GMCnet] Transmission Leak [message #326351 is a reply to message #326347] Sun, 26 November 2017 12:40 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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Whenever we have problems, we tend to over do things just to be sure. Yes
putting on sealer on both sides cannot be bad.


On Sun, Nov 26, 2017 at 8:29 AM, tom geiger wrote:

> Jim, when you say take some gasket seal and dab it at the bolts, are you
> sayinging I do a circle around the bolt holes to tack the gasket and flange
> together or just glob some at the bolt hole before the bolt goes in?
>
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Jim Kanomata
Applied/GMC, Newark,CA
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Jim Kanomata
Applied/GMC
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www.appliedgmc.com
1-800-752-7502
Re: Transmission Leak [message #326376 is a reply to message #322909] Sun, 26 November 2017 17:57 Go to previous messageGo to next message
Larry is currently offline  Larry   United States
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I don't think that any of the bolts that hold the trans pan in place are "through" bolts. Without a drain plug in the pan, you must take all of the bolts out and lower the pan to drain. If the bolt holes in the trans were through holes, when you take the bolt out, trans fluid should pour out of the hole...It doesn't. I have found that trans fluid does not come out until all bolts are out and you crack the pan loose from the trans. Then it POURS out!! So the last time I took the pan down, I looked for through bolt holes and found none. I'm not sure that extra silicone sealer at each bolt would do anything, but then it won't hurt either. JWIT

Larry Smile
78 Royale w/500 Caddy
Menomonie, WI.
Re: Transmission Leak [message #326402 is a reply to message #326376] Mon, 27 November 2017 10:58 Go to previous messageGo to previous message
roy1 is currently offline  roy1   United States
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On my transmission some were thru bolt holes and some were not. The thru ones needed a flange bolt and gasket or sealent so they wouldn't weep fluid.

Roy Keen Minden,NV 76 X Glenbrook
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