Home » Public Forums » GMCnet » Transmission pan leaks
| Transmission pan leaks [message #367043] |
Mon, 04 October 2021 17:32  |
tgeiger
Messages: 518
Registered: February 2006
Location: kansas city
Karma: -1
|
Senior Member |
|
|
Ok, I’m going to take another swing at this transmission leak issue. This time I’m collecting all the info I can to address all possible leaks. O rings, rubber gasket with RTV, I’ll re-flatten the bolt hole flanges on my OEM pan, I’ve read that the Ragusa pan still leaks and it’s not apparently because of porosity. I’ve even read and saw a picture of someone installing a overflow bottle for the transmission fluid. Worth a try too if it prevents it leaking. Point is, I’m wanting to cover the gambit to get this thing to stop leaking!
Any ideas welcome!! I’m tired of the old girl’s incontinence on the driveway.
Thanks,
TG
Tom Geiger
76 Eleganza II
KCMO
|
|
|
|
| Re: Transmission pan leaks [message #367051 is a reply to message #367043] |
Mon, 04 October 2021 21:53  |
TR 1
Messages: 348
Registered: August 2015
Location: DFW
Karma: -7
|
Senior Member |
|
|
FWIW, my Ragusa pan is dry as a bone... No gasket. I use a thin layer of gray RTV on both sides, hand snug all bolts, then when the RTV has set up for a few hours, finish tightening down to rated torque. I have a overflow on the vent line.... (Polaner all fruit jar mounted near the wiper motor). I used to get around 1/2" or so of fluid in the jar between changes... However, since I upgraded to 3/8" transmission lines and added an auxiliary cooler, the jar has been dry as a bone as well. Same amt of fluid on the dipstick, checked the same way. No other changes.
For a stamped steel pan, putting a straight edge and hammering the bolt holes flush from time to time is always a good idea. If you go the RTV route, make sure the pan and trans mounting area are as fluid free as possible. Do a final wipedown with brakeleen or MEK before applying RTV.
FWIW, I use Amsoil ATF... In my experience synthetic ATFs tend to leak more as well.... So very pleased I have no leaks.
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX
|
|
|
|
| [GMCnet] Re: Transmission pan leaks [message #367052 is a reply to message #367051] |
Mon, 04 October 2021 22:32 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
|
Senior Member |
|
|
Be sure to check the leak at the Final drive/ trans.
Be sure to snug the bolts as the final seals the trans.
On Mon, Oct 4, 2021 at 7:53 PM Mark Sawyer wrote:
> FWIW, my Ragusa pan is dry as a bone... No gasket. I use a thin layer of
> gray RTV on both sides, hand snug all bolts, then when the RTV has set up
> for a few hours, finish tightening down to rated torque. I have a
> overflow on the vent line.... (Polaner all fruit jar mounted near the wiper
> motor).
> I used to get around 1/2" or so of fluid in the jar between changes...
> However, since I upgraded to 3/8" transmission lines and added an auxiliary
> cooler, the jar has been dry as a bone as well. Same amt of fluid on the
> dipstick, checked the same way. No other changes.
>
> For a stamped steel pan, putting a straight edge and hammering the bolt
> holes flush from time to time is always a good idea. If you go the RTV
> route,
> make sure the pan and trans mounting area are as fluid free as possible.
> Do a final wipedown with brakeleen or MEK before applying RTV.
>
> FWIW, I use Amsoil ATF... In my experience synthetic ATFs tend to leak
> more as well.... So very pleased I have no leaks.
> --
> Mark S. '73 Painted Desert,
> Manny 1 Ton Front End,
> Howell Injection,
> Leigh Harrison 4bag and Rear Brakes,
> Fort Worth, TX
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
--
Jim Kanomata ASE
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.gmcrvparts.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
|
|
|
|
| Re: Transmission pan leaks [message #367056 is a reply to message #367043] |
Tue, 05 October 2021 09:58 |
tgeiger
Messages: 518
Registered: February 2006
Location: kansas city
Karma: -1
|
Senior Member |
|
|
Thanks guys on this info, this will help. Jim, I just replaced the oil and gasket on the FD. Got the correct gasket single layer gasket with the internal breathing channel for the vent hole in it. I also made sure the vent hole was clear to breath. So I see no signs of leaking from it and think I’m good on it sealing. Will read more to understand the sealing relationship between the FD and transmission reservoirs.
Thanks,
TG
Tom Geiger
76 Eleganza II
KCMO
|
|
|
|
| Re: Transmission pan leaks [message #367057 is a reply to message #367056] |
Tue, 05 October 2021 10:34 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
|
Senior Member |
|
|
there is two oil seals on the pinion portion of the final drive. One seals the final drive fluid in, the outer seals the transmission fluid out. between those seals is a weep hole that goes out of the final drive near where the dipstick tube enters. so in theory if one of the seals goes bad, you will have leak out the weep hole to let you know.
the final drive is bolted to the transmission and there is a felt gasket between the two keeping the transmission fluid inside the tranny.
Think you have the rest, there is seal on the shift arm. need the modulator to have a good o-ring. also good o-ring seal on the kickdown wire plastic thing.(might rtv that too). and a good o-ring on the dipstick tube.
the dipstick needs to vent. and the tranny needs to be in good order as well. Had one owner chasing a vent overflow issue that would occur only when tranny was hot. that was a bad seal internal.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
|
|
|
|
| Re: Transmission pan leaks [message #367075 is a reply to message #367043] |
Wed, 06 October 2021 06:52 |
tgeiger
Messages: 518
Registered: February 2006
Location: kansas city
Karma: -1
|
Senior Member |
|
|
Ah, I understand I believe. These are inner seals involved in the connection of the two and not part of the FD cover gasket. Fingers crossed I don’t have issues with the seals. I last spring had the transmission system serviced and had the filter replaced and the service center did not mention any issues. A month ago I serviced my FD to use the synthetic oil from Valvoline. I used the correct gasket that allowed the small vent hole to breath. So I think I’m hopefully good pertaining to the inner seals.
As far as the O-rings, I’m going to check all of the locations after I’ve done a good washdown of the transmission. If I happen to have leakage at the cooling lines conncetion at the transmistion, would those involve any o-rings?
Thanks,
TG
Tom Geiger
76 Eleganza II
KCMO
|
|
|
|
|
|
| Re: Transmission pan leaks [message #367077 is a reply to message #367075] |
Wed, 06 October 2021 09:04 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
|
Senior Member |
|
|
Tom,
one item I have found to work really well to find leaks, is UV die. You have to be careful and really get the parts clean, but a little UV die goes along way and you can get a light and really follow the fluid tracks.
there are different uv die products that are compatible with the different fluids, so be careful on what one you use for each fluid.
https://www.amazon.com/Interdynamics-Certified-Fuel-Systems-Ounce/dp/B002M4G24U/ref=sr_1_2?dchild=1&keywords=tranny+fluid+uv+dye&qid=163352901 0&sr=8-2
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
|
|
|
|
| [GMCnet] Re: Transmission pan leaks [message #367078 is a reply to message #367076] |
Wed, 06 October 2021 09:02 |
stu@97381.com, Emery
Messages: 232
Registered: June 2020
Karma: 2
|
Senior Member |
|
|
Tom
The cooling lines at the transmission don’t use o rings but since you are clamping a steel line against a steel casting you might have to use copper washers in the end to get a good seal.
Emery Stora
77 Kingsley
Frederick CO
> On Oct 6, 2021, at 7:47 AM, Bruce Hislop wrote:
>
> Check for leakage around the manual shifter shaft as well. When the torque converter leaks down after being parked, the fluid level can be above it.
>
>
> Its not a seal like other Turbo-Hyromatics, its an O-ring, but it's not too hard to change.
>
> Manny says a lot of rebuilders don't change it. Mine was hard and just crumbled when I removed it.
>
> Look here for more details and a diagram.
>
> https://www.gmcmotorhome.org/resources/the-elusive-th425-manual-shifter-shaft-seal.51/
>
>
>
>
> --
> 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:
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
|
|
|
|
| Re: Transmission pan leaks [message #367091 is a reply to message #367043] |
Wed, 06 October 2021 16:15 |
tgeiger
Messages: 518
Registered: February 2006
Location: kansas city
Karma: -1
|
Senior Member |
|
|
Thanks guys, this is good. I’ll cover these areas as well. Kinda funny, moved the motorhome over to the other side I typically park it on and it apparently has lost enough fluid that it didn’t move forward for a few seconds. So I’m going to try to calibrate the dipstick as well once I open up and drain out the pan. All good info guys!
Thanks,
TG
Tom Geiger
76 Eleganza II
KCMO
|
|
|
|
| Re: Transmission pan leaks [message #367218 is a reply to message #367091] |
Fri, 15 October 2021 18:29 |
Carl S.
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
|
Senior Member |
|
|
My Ragussa pan does NOT leak at all. I install it with a dry gasket and tighten the screws in a diagonal pattern to the recommended torque. No leaks, no seepage.
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 pan leaks [message #367225 is a reply to message #367043] |
Sat, 16 October 2021 10:46 |
tgeiger
Messages: 518
Registered: February 2006
Location: kansas city
Karma: -1
|
Senior Member |
|
|
Well, got the new gasket and was planning on working on this when I get back from our weekend camping trip, but now our HOA posted up in our monthly flyer that no campers are allowed in our driveways and in addition home owners are not allowed to work on their vehicles in the driveways that on both accounts I would be flipping the board the bird so maybe I do this all over in my storage site. Now these bylaws were written 40+ years ago when the neighborhood was brand new and they thought they were all that and a bag of chips but that was 40 years ago. The neighborhood has changed a bit but some, board members seemed to have lost perspective on current conditions of things. For example, the bylaws still state we are to replace our cedar shaked roofs withe the same. Well that has fallen by the way side because of its dangers and crazy replacement costs and some insurance companies just won’t cover it. Anyhow, some of these bylaws need to be reviewed. Times do change things.
So I’m going to comply and take up my transmission leaks over at my storage area instead of in front of my garage. Heck, just realized if I did do it at my house I’d be violating another bylaw of the HOA. We are not to have our garage door open for any length of time. See what I mean, things just get carried away on bylaws. Anyhow, will let you guys know how things go when I get to it over at the storage area. Cool dude that owns the place, no bylaws there!
TG
Tom Geiger
76 Eleganza II
KCMO
|
|
|
|
| Re: Transmission pan leaks [message #367292 is a reply to message #367218] |
Sun, 24 October 2021 08:16 |
tgeiger
Messages: 518
Registered: February 2006
Location: kansas city
Karma: -1
|
Senior Member |
|
|
I have now got the transmission pan off, flanges flattened and reinstalled back on and bolted up. While I have the fluid drained I thought I’d check the other upper sources of leaks. Now I’ve done some searching and maybe not enough but I see other items identified such as cooler lines, dipstick leak and speedo cable leak, to which I think I have. In my search I’m not seeing anything definitive on repairs for the speedo cable leak? Is it just a new cable replacement? Also what is the best repair for cooling line leak? Is it a copper washer? I believe the dipstick leak repair is with RTV per Jim K’s response to a post.
Thanks,
TG
Tom Geiger
76 Eleganza II
KCMO
[Updated on: Sun, 24 October 2021 08:17] Report message to a moderator |
|
|
|
|
|
Goto Forum:
Current Time: Tue Sep 24 23:33:47 CDT 2024
Total time taken to generate the page: 0.03556 seconds
|
GMCforum
Search
Help
Register
Login
Home
