O-ring size help please

[Stocker]

How to find the exact size o-ring for my transmission dipstick tube (72 K20)?

The one I removed seems quite new (I paid a shop to replace it a few years ago), but is leaking -- so it may be the wrong one. Comparing by size, it seems to be a #112, which is 11/16" OD x 1/2" ID x 3/32" thick.

It seemed to fit the tube properly, but it was leaking. I have read that some brands are a bit thicker than others even though they are listed as the same size. Unfortunately my local NAPA has no o-rings, and the ones at Ace hardware (my only other choice) look exactly the same size as my old one.

Any help would be appreciated! Thanks...

[1972_Buford]

I don't know the size but I believe this was the one I just bought for mine.

http://www.oreillyauto.com/site/c/de...smission+seals

Did you get the bolt off finally? did you get it from the inside??

[Stocker]

Yup.... I'll post details in the other thread.

[Stocker]

Originally Posted by 1972_Buford

I don't know the size but I believe this was the one I just bought for mine.

http://www.oreillyauto.com/site/c/de...smission+seals

I don't suppose you have the actual size specs for that? The website doesn't show anything.

Just as importantly... it doesn't leak, does it?

[72 K20]

I'm thinking that some of the automatics had a shouldered sleeve instead of an o ring.

I don't recall the applications but do remember changing a few of them.
Might be something to check into.

[Stocker]

Originally Posted by 72 K20

I'm thinking that some of the automatics had a shouldered sleeve instead of an o ring.

I believe that's a newer design -- it takes a "top-hat" seal, and the tube itself is made differently to work with the improved seal.

As to o-ring size, I found this thread http://www.stevesnovasite.com/forums...d.php?t=200111 which indicates the correct size is a #113, with 3/4" OD, 9/16" ID, and 3/32" thickness.

The one I removed appears to be #112, with 11/16" OD, 1/2" ID, and 3/32" thickness.

I have been unable to locate the thicker Danco brand o-rings mentioned in the above link.