TH400 to 203 Adapter with doubler keeps leaking ATF, any ideas???

[dawson444]

Where my TH400 bolts to my 203 adapter keeps leaking tranny fluid. It did it a few months ago when the tranny was on its way out so I had to pull it anyways and didn't think much of it. Now it has been back in for about a week and I have wheeled it once and it is leaking again. Any ideas????

It is a doubler with two crossmembers under it. I have been putting a gasket on and smearing RTV around it, should I use just one of the other? Could heat be messing with the RTV? I am pretty sure the tranny got real hot this weekend. I have also been thinking about getting longer bolts that thread all the way through the tail of the transmission "ears" and putting nuts on them to get them super tight.

I am open to any ideas. Thanks!

 

[boz42]

The bolt that go through the adapter into the trans are suppose to have an o-ring under them. These bolt also have a large head at the base than a regular bolt head. They are flared out where thay meet the adapter.

Hope that helps.

 

[dawson444]

that helps some...I did replace the large o ring there so I don't think that is it. The bolts I have do have washers on them, think those would be good enough?

 

[4X4HIGH]

The tranny adapter uses a large O-ring to seal to the tranny case. Did you install a new O-ring there?

 

[dawson444]

yea, it was an o ring that goes around the male part of the adapter and down into a grove in it. I got the o ring from GM, about 4 or 5 inches in diameter.

 

[dawson444]

anyone else?

 

[dawson444]

just bumping this to the top again to see if anyone has any ideas?

I have also been told to look into putting helicoil's inside all the bolts to give it "new" theads to grab. Any insight on that?