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gmebey · 09-05-2014, 11:14 AM

Here is the short version of the long story of the leaky TH400, look at my past post and you will get the whole story.

1) Replace pan gasket on OEM pan with a cork type. However the pan lip had seen better days. I did flatten it and reuse the OEM pan.

2) Replace pan with cheap cast aluminum (eBay thing) using the rubber gasket that came with it

3) Switched to the to the Moroso gasket (93103)

4) Had the transmission totally rebuilt and found out that front bushing and seal were shot, needless to say this was most likely my source of the major leak.

Now that I have freshly rebuilt transmission I still have a leak and at this time I suspect that the cast pan is my source of the problem. I did check the flatness of the pan, and it seems to be OK. But it is leaking at the rear around a couple bolt holes. This makes me thing that cheap cast pan has insufficient area around bolt holes….I think.

Anyway here are my questions:

1) Has any one tried a cheap cast aluminum pan with success of NOT leaking? Digging on the internet I have found other blogs, post…etc that claim that the surfaces of the cheap pans are to smooth, they are poorly designed…etc.

2) Since I’m considering replacing the pan with a better quality one. Suggestions please?

09-05-2014, 11:14 AM	#1
gmebey Registered User Join Date: May 2011 Location: Fort Collins, Colorado Posts: 95	TH400 pan still leaking! Here is the short version of the long story of the leaky TH400, look at my past post and you will get the whole story. 1) Replace pan gasket on OEM pan with a cork type. However the pan lip had seen better days. I did flatten it and reuse the OEM pan. 2) Replace pan with cheap cast aluminum (eBay thing) using the rubber gasket that came with it 3) Switched to the to the Moroso gasket (93103) 4) Had the transmission totally rebuilt and found out that front bushing and seal were shot, needless to say this was most likely my source of the major leak. Now that I have freshly rebuilt transmission I still have a leak and at this time I suspect that the cast pan is my source of the problem. I did check the flatness of the pan, and it seems to be OK. But it is leaking at the rear around a couple bolt holes. This makes me thing that cheap cast pan has insufficient area around bolt holes….I think. Anyway here are my questions: 1) Has any one tried a cheap cast aluminum pan with success of NOT leaking? Digging on the internet I have found other blogs, post…etc that claim that the surfaces of the cheap pans are to smooth, they are poorly designed…etc. 2) Since I’m considering replacing the pan with a better quality one. Suggestions please?