t/h 400 transmission yoke

[george stenstrom]

I have a 1971 455 with t/h 400 transmission in my 1935 Ford.I noticed i was leaking tranny fluid out of the tranny yoke.So i took the driveshaft out and noticed there is a hole in the center of yoke where it meets the output shaft what is this hole for? would it hurt anything to weld it closed ? thanks george

[guyopel]

This is a vent hole and if you have a fluid leak there the trans. fluid level is too high ..now if you check your trans. fluid level ( hot ) and it is reading normal then your torque converter may be draining back into the trans. and causing the leak ( drain back of the converter is controled by a check valve in the front pump..may just be stuck or trash ) HTH
John

[BigRivy]

No it will not hurt to weld it shut. Had the same problem with my '83 Chevy pickup when I swapped the 700r4 out for an older model th350. Guys at the tranny shop that I deal with said that the 700r4 had a different way to seal the splines, O-ring on the output shaft or something. I can't remember as it has been several years. Spot weld on the hole solved the problem right quick. This was the remedy offered by the tranny shop. 60,000 miles and no problems. Might not be the right way but it worked for me. Good luck.