TH400 pan still leaking! - Page 2 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

davepl · 09-09-2014, 09:55 PM

Quote:

Originally Posted by mechanicalman

Or, take the advice of someone else who has went through 4 gaskets and 2 pans and never fixed the leak and had to hire someone to fix it for him.

Post a picture of your truck, I'll post one of mine. We'll see who the real mechanic is.

**Grumpy old man** · 09-09-2014, 10:44 PM

Quote:

Originally Posted by davepl

Post a picture of your truck, I'll post one of mine. We'll see who the real mechanic is.

Well...There goes the neighborhood !

davepl · 09-09-2014, 11:00 PM

Everybody knows I'm the toughest stranger on the Internet :-)

gmebey · 10-04-2014, 09:27 PM

Update.

I cleaned off the tranny and look closer for the leak. There is two, governor cover and the tranny pan along the front. I removed the pan and checked the flatness...... It is not flat and has about a 1/64 to 1/32 gap between a couple of the bolt holes.

Hmm a cheap cast pan = leak!

Any thoughts on Moroso 42020 pan or similar?

**leddzepp** · 10-04-2014, 09:29 PM

Weld the pan on there. It will never leak again.

gmebey · 10-04-2014, 09:37 PM

Wow. That may work. Lol

cwilkie · 10-04-2014, 10:13 PM

Mine would slowly leak out a lot of fluid if parked for a long time. I changed the gasket and pan numerous times. It turns out the shaft of the speedo hear was hollow all the way through. That little pin hold caused it drop out of the cable and onto the pan. After I changed speedo gears it didn't leak again. That was my th409 leak experience.

09-09-2014, 11:00 PM	#28
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: TH400 pan still leaking! Everybody knows I'm the toughest stranger on the Internet :-) __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

10-04-2014, 09:27 PM	#29
gmebey Registered User Join Date: May 2011 Location: Fort Collins, Colorado Posts: 95	Re: TH400 pan still leaking! Update. I cleaned off the tranny and look closer for the leak. There is two, governor cover and the tranny pan along the front. I removed the pan and checked the flatness...... It is not flat and has about a 1/64 to 1/32 gap between a couple of the bolt holes. Hmm a cheap cast pan = leak! Any thoughts on Moroso 42020 pan or similar? Last edited by gmebey; 10-04-2014 at 09:28 PM. Reason: Spelling

10-04-2014, 09:29 PM	#30
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 20,024	Re: TH400 pan still leaking! Weld the pan on there. It will never leak again. __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man RIP FleetsidePaul

10-04-2014, 09:37 PM	#31
gmebey Registered User Join Date: May 2011 Location: Fort Collins, Colorado Posts: 95	Re: TH400 pan still leaking! Wow. That may work. Lol

10-04-2014, 10:13 PM	#32
cwilkie Chance Join Date: Sep 2001 Location: Belcourt ,ND, USA Posts: 750	Re: TH400 pan still leaking! Mine would slowly leak out a lot of fluid if parked for a long time. I changed the gasket and pan numerous times. It turns out the shaft of the speedo hear was hollow all the way through. That little pin hold caused it drop out of the cable and onto the pan. After I changed speedo gears it didn't leak again. That was my th409 leak experience. __________________ 1968 Chevrolet Stepside BB 396 w/TH400 1972 Chevrolet 3/4 Ton 4x4 BB 496 w/TH400



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