......i don't think ive ever had an automatic that doesn't leak......
Asking me, this is a correct observation..... I'll share my thoughts on this matter..
There are many reasons for these leaks,...choose which one you like;
1) Incorrect stored seals,...I've seen lipseals hanging on a nail mounted on the wall....needless to say this will ruin the seal.
2) Incorrect installed seals
3) Seal design does vary,... both elastomer (rubber) cross section, and springforce.
4) Converter axle surface (Scratch, oval, etc...).
5) My personal favorite,....the converters are welded together...... this WILL NEVER make them perfectly aligned between the two ends.
Once out of the welding jigg, heat residual stresses will make imperfection in angle, and/or radial offset...
...so the radial clearense in the tranny oilpump, how close to perfect the converter ended up after welding, the radial clearence between crank and converter, this all comes into play....
There is not a seal in this world that can seal a fast rotating shaft running excentric....for any long period.....
Why does not newer cars have leakage issues ?
Better = narrower tolerances, years of experementing with guiding vanes on the rubber seals, and "threads" on the surface of the rotating part, better quality seals .... maybe
?
....come to think of it,...my leak is worst at standstill.
I was told this is caused by the converter fluid draing back to the tranny sump, and "overflowing it" up to the level where the lipseal is located...so that the lipseal is leaking during standstill..... IF THIS IS TRUE,........perhaps newer cars has a way to atleast cure THAT cenario....
AGAIN these are my thoughts,... and are open for debate.....
