guys i really need your help if you know how to help me and my dad please reply

[67chevy1series]

okay today i go out side and notice i the battery is dead on my dads 1970 chevy lwb 1/2 ton because my mom left the lights on so i put it in nuetral and move it so i can pull my truck out of the garage to clean it , and when i move it i notice there was about a pint of tranny fluid on the ground! so i look at the tranny fluid its says''add" well i go under and wipet the tranny Xmember clean and wacth it after about 5 mins there is already 5 spots were tranny fluid is dripping again what do we do? what is wrong?

[csb#356]

Where's it look like its coming from, Front, back, pan, dipstick. Need more info. I'm assuming its a 4x4

[chevy_mike]

You likely have a seal that is bad and when it sits the converter is draining back, which will raise the fluid level higher then the seal that is leaking. It then drains thru that seal until the fluid level is below that point.

As for which seal, it can be any number of ones but a really common one is the o-ring on the dipstick where it comes into the trans case. It can be a real output seal, selector shaft seal, pan gasket, etc. You really need to find out where the fluid is dripping/leaking from to know what to fix.

Also, you are checking the fluid while it is running, after cycling thru all the gear selections and putting it back into Park, correct? Ideally you want to do this when it is hot as well. You can overfill the trans which can also cause it to leak.

Good luck.

[67chevy1series]

it is dripping from ?????? down to the tranny crossmember then onto the floor so anywhere above the crossmember....yes it is a 4wd 1/2 ton chevy stock height

[SeventyOne]

If it's dripping onto the transmission/tcase crossmember it might be the rear seal or even the T-case. You're going to have to get under the truck with a flashlight and find where the leak is originating from - maybe even remove the trans tunnel/hump if it helps.

If you can't tell, clean everything up real well then let it sit and see where the new drips come from.

[67chevy1series]

thank you!

[Mike C]

Some TH350s have a vent hole in the end of the trans yoke, and I guess an internal seal. This tends to leak after the truck has been parked for several days and is a pain to track down. Something else to look for.

[kingburnett]

Originally Posted by SeventyOne

If it's dripping onto the transmission/tcase crossmember it might be the rear seal or even the T-case. You're going to have to get under the truck with a flashlight and find where the leak is originating from - maybe even remove the trans tunnel/hump if it helps.

If you can't tell, clean everything up real well then let it sit and see where the new drips come from.

Like SeventyOne says clean and then put a piece of cardboard under to find the first drips. Also check any tubing lines especially at the end fittings. Be sure you are on level ground when topping off the fluid too.

[67chevy1series]

thanks guys this is all good info and each of these will be tried we are gonna take it down to see what is wrong and if its easy we will fix it if not then we will jave it fixed

[jbclassix]

It's not leaking, it's just marking it's territory.

Or, like I tell the operators (drivers) at work. If you let it leak long enough, it will eventually stop.

Sounds like the problem can be fixed by simply installing a 700r-4

Seriously though,

you may want to wear some grungy clothes, bring a stiffer bristle brush like a dish washing brush and some dawn, take it to the car wash, and clean the padookie out of the tranny and t-case.

Now that all the grime is gone, you can watch a clean surface to see where the leak is coming from. Seals for the TH350 are cheap. It could be the pan seal, it could be the governor cover seal... both are easy to change. If you have a chrome pan, than that is whats leaking. Chrome makes shiny leaks. I have some really good tips for leak-proofing a tranny pan if you need them.

[67chevy1series]

its not the pan he has a beautiful aluminum pan he said it has a ''pin'' that is sticking out and it looks like leaking on the upper right above the t case so he says what is it? he also says there is a line coming off of it?

[jbclassix]

yeah if its an aluminum pan than its probably not leaking. I may be wrong, but you may be seeing the vacuum modulator seal leaking.

[67chevy1series]

thanks jeremy its just wierd how it all of the sudden happened! to bad my 67 wasnt running it could take the place of my dads truck! with the help of your parts i will be alot closer!

[plummen]

tighten pan bolts while youre under there

[SeventyOne]

Originally Posted by plummen

tighten pan bolts while youre under there

Maybe not - if they are properly torqued tightening the bolts on that aluminum pan may cause problems. Just check the torque on it - but if it's not leaking why mess with it...

[plummen]

aluminum pan on a turbo 350? very few 40 plus year old transmisions have pan bolts that are all tight,had a friends 60 chevy convertable in garage last spring that he hadnt driven in 2 years because somebody told him oil leak was being caused by bad rear rope seal on pan/crank.
turns out all the oil pan bolts were loose,i tightened everything up and he hasnt had a leak since.
sometimes simple repairs are the right answer

[SeventyOne]

Originally Posted by plummen

aluminum pan on a turbo 350?
sometimes simple repairs are the right answer

He said aluminum pan...

You are right - start with the easy/cheap repairs and move on. Like I said though, check the torque on them rather than just tightening the bolts. Regardless, it doesn't sound like his leak is from the pan.

[67chevy1series]

well it was at the shop almost the hole day and now my dad is on his way to go get it back it was the tranny/t-case gasket ,it was 150 i think ,its prob. only 20 for the seal and the 130 is in labor ! it must be hard having to take off all of this stuff and then put it back together again.......

[OrrieG]

$130 sounds fair to me considering you have to pull both drive lines, shift linkage, maybe move the exhaust, possibly cross member, horse the transfer out and back in. They weigh about 300# and do not have a good balance point so its a real wrestling match.

[67chevy1series]

exactly what i was thinking! they said they may have to take the tranny out....we are gonna get it toda turns out they werent done yesterday...