transmission venting

[krazykyle]

is there anyway to vent a transmission casing better.seem like i might be having a problem with to much pressure maybe.i have a 350 turbo with a manual shift valve body.i have a problem with leaks.first one was from the dipstick tube fixed that with a double o-ring tube,then it started pushing fluid up the tube and came out the top.the new tube i installed is a short flex one.fixed that one.now one bolt was leaking/fixed.so now it starting to leak out the tail shaft.i'm getting pissed and yes i did check the vent tube but the tube is missing,seem like it got lost so where.any ideal what the hell is going on.

 

[DRIVEN]

Unless the factory vent is plugged it should be more than adequate. Dipsticks aren't usually air tight either so consider that a second vent. Is it getting hot? How big is your cooler?

 

[krazykyle]

no cooler

 

[beermonkey9417]

no cooler

well theres yer problem...

 

[megaladon6]

are you sure you didn't overfill the trans? is the fluid foaming at all?

 

[krazykyle]

no foaming just leaking.it seems like everytime i go out i come home and the next day i have a puddle of fluid.why would a cooler help.

 

[bjohn07]

a cooler keeps the trans fluid at a good temp. 175 degrees is a good operating temp. anything over 200 is bad. so without a cooler ur for sure over 200 degrees. at anything over 200 degrees fluid burns losing its ability to lubricate and oxidizes leaving crap and deposits all in the trans. the rubber gaskets and seals will crack and cause leaks cuz of the heat. and also the heat can warp internal components. no cooler=very short life trans. especially if u take it to the track or ur running a stall converter.

 

[DRIVEN]

Aside from helping the fluid last longer, a cooler keeps the fluid from expanding as much. Ever seen a burned up RV? That usually happens when they overheat the transmission while pulling a hill. The fluid expands and comes out the vent, gets on the hot exhaust, and starts a fire. Heat dramatically reduces the life of ATF so you can't have too much cooler.

It sounds like you are dealing with two separate issues; heat (expansion) and good old fashioned leaks. Remember, the TH350 hasn't been new since 1980. Unless yours has been resealed, you are dealing with 30 year old seals which only get more brittle when overheated. One other point - switching to synthetic fluids on aged engines and transmissions can cause leaks that you never had also.

 

[krazykyle]

just order a b&m super transmission cooler.i'm thinking about running the fluid through the radiator then back thought the cooler and out the radiator.i was thinking that would cool it much better. :shock:

 

[megaladon6]

One other point - switching to synthetic fluids on aged engines and transmissions can cause leaks that you never had also.

sorry, have to correct this again. on MODERN, QUALITY, synthetics, this had never been shown. it has been shown that loose piston rings and syn oil can produce more smoke in the exhaust (usually seen on chevy's), but newer (as in post 1990) syn oils have had aromatics added to the mix. (aromatics are hydrocarbon components that actually cause seals to swell. early syn's had eliminated them in the purification process and it did cause leakage problems, especially on old seals. also, newer material seals are of a different material that is better altogether and doesn't contract as much with age.)
however, from what i've seen syn ATF is still not recommended.
i (and my family) have run synthetic in an 86 vw diesel, 89 vw gasser, 97 vw TDi, 2001 chevy 2500hd (6.0l), acura mdx 3.5l, another 97 vw TDi, 98? ford explorer, 2004? honda accord, and a 97 cavalier that spends more time sitting than running. the 2500hd did have slightly more smoke, but no leaks, possibly slightly cooler, and better MPG. all the others had better MPG and zero engine problems.
the only reason i don't run it in my monte is the lack of ZDDP additive. and will probably change on the next oil change.