Trans Dipstick Tube Leaks

[44SAA]

Gentleman- the fam just recently picked up this '80 C20. I say fam cause me, my two boys and father have all been working on it together. In short, I'm identifying leaks. Biggest culprit seems to be trans. Dropped the pan, replaced the seal, bullet and gear. Pan leak has ceased. However, while refilling with ATF I discovered the dipstick tube has a crack or worn spot. I'm pretty green when it comes to wrench turnin' so here are my 2 questions:

1) when driving, does the ATF run up the tube?
2) can I remove the tube by simply pulling upward on it?

Also, special,thanks to Jocko for providing me some coaching during the search process.

[mongocanfly]

Pull the dipstick tube out..there's a seal on the end of it in the trans..sometimes it'll come out with the tube ..sometimes it'll stay in the trans..either way replace that seal..there should be a bolt that holds the tube in place..remove that bolt and it should pull straight out with some wiggling..seal should look like this..

[44SAA]

Thanks Mongo, I'll go for it. If for any reason I have to get into that pan again... That bolt attaching the tube must be hard to see. May be time for these- priceless when you ain't sure

[44SAA]

Thanks Mongo, I'll go for it. If for any reason I have to get into that pan again... That bolt attaching the tube must be hard to see. May be time for these- priceless when you ain't sure

[raceman6135]

Originally Posted by 44SAA

That bolt attaching the tube must be hard to see.

It uses one of the bolts that holds the transmission to the engine, so it is often quite tight to the firewall.

Here is a photo (linked from another site) to give you an idea where the bracket is:

[cadillac_al]

You will most likely find that you have the old style O-ring instead of that nice seal that Mongo posted. Some people have trouble with the old O-ring but I do prefer the newer style with a nice seal. Somebody gave me a part # for the newer dipstick. I'll see if I can still find it. I just bought an aftermarket one last year from Hughes I think.

GM part # 14046820

[44SAA]

The bracket retaining my tube is missing, thus it wobbles a lot and is only held in place by the gasket attaching it above the pan. All the rubbing against the firewall wore a hole in my tube.

When driving, does ATF run upward in the tube?

[hewittca]

It can leak from there, yes. I would definitely get a new dipstick tube since yours has a hole in it and the bracket is broken/missing. I recently rebuilt my trans with the help of my dad who has rebuilt 100's of GM transmissions at his shop. He puts a very small bead of silicone on those dipstick o-rings because he said they always leak. We did that on mine and there have been no leaks.

[44SAA]

Good grief this tube won't come out. Yes, there is no retaining nut and I pulled the bottom of the tube out of trans. Any issue with me gently hammering upward on tube?

[hewittca]

Originally Posted by 44SAA

Good grief this tube won't come out. Yes, there is no retaining nut and I pulled the bottom of the tube out of trans. Any issue with me gently hammering upward on tube?

That's interesting. With the tube out of the trans and the bracket unbolted or broken off, there should be nothing left holding it in place and should drop right out. My guess is it's hung up on something and I would not hammer on it to get it out until I figured out what it was stuck on.

[44SAA]

Got the tube out, and it was a bear. Son was under vehicle holding lower part of tube and I was in engine bay coaxing up the top part. The bends in the tube and the limited space against the firewall were frustrating. Oh yea, a hole had worn in the tube as the support bracket was long gone- it was just rubbing against the valve cover. Result was pretty substantial atf leak.
Picking up replacement tomorrow plus new boot seal- please tell me the install is easier than the removal..

[mongocanfly]

To make install a little easier you can put a floorjack under the trans and pull the crossmember loose and drop the back of the trans down slightly to give you more room.....makes it a little essier to get to that mounting bolt on trans..