[East]

Could someone with a 68 or 69 Firebird with a TH 400 transmission please tell me the length of the dipstick (fill indicator NOT tube)?

Preferably if the Firebird has factory TH 400 and factory dipstick tube. I know that the original dipstick tubes are as common as hens teeth. But maybe no so uncommon within the members of these forums.

I have included pictures of TH 400 for 68 and 69 Firebird.

[Squidward]

I replied in the street section. 26.625" from hilt to tip for the tube/stick combo I have. It was non original to a friend's 69, but fit nicely in his, and will find it's way into my 67.

[East]

I think that I will be pretty close of dialing in the indicator dipstick. It is not easy to obtain an original th400 tube for a 1969 Firebird.

My car originally had a th350 so I probably used the dipstick from that. It has a kink in it from my past expertise of forcing things to comply to my will.

Since those days back to 1982, I have been replacing everything back to factory parts. Unfortunately, original used parts are expensive.

[East]

Fill indicator research is in between 26 to 27 inches long. This is what Squidward reported.

I am going to remove pan and use pan mating surface as measuring point for future dipstick indicator reference mark.

[East]

I can now install the dipstick and tube to compare with transmission pan mounting surface for markings on the dipstick fill indicator.

From what I have found on the Internet, I cannot decide whether the proper fill level is at the pan mounting surface or 1/4 inch above the pan mounting surface.

If I had removed the dipstick and tube from a 1st generation Firebird myself, and knew that the dipstick fill indicator was original from factory, I would not be skeptical. I would have put a fork in it and called it done.

As it stands now, the dipstick tube appears to be correct. The dipstick fill indicator only looks like the ones that I have seen in pictures on the Internet. Hence the extended posts regarding the questions regarding fill indicator length.

If anything, I hope that the pictures and information helps someone else who needs to know.

[East]

I bought the tube from Frankyboy455 several weeks ago. I then searched a second time to find the dipstick fill indicator using pictures that I had found.

Squidward provided measurements to help with matching the parts.

On to the next.

[Squidward]

Yay! Glad you are making progress.

My 73 Formula with TH400 had a poor sealing early style oring tube. I had a large cooler, mounted kinda high, which would gravity backflow fluid when parked. It then slightly overfilled the pan and leaked out.

Keep us posted on your build!

[bobzdar]

I have the original '67 th400 from my 400 car sitting out in my garage, complete with fill tube and dipstick, let me know if measurements of that would help.

[East]

The dipstick (fill indicator) that I found was by comparing it to pictures. Do you have the same one?

Is also around 26 1/2 inches?

If not, I was prepared to make a mark on mine to where the pan surface compares to the fill indicator. It's about all I can do since I have what I have.

I appreciate all the help from you all. It's hard to only have pictures to work with. It's even harder to get under the car to install the parts. It seems like everything that I used to do in good time takes longer for me to complete now. I'm only 61 but I have noticed this for a while.

[East]

I pulled the pan to drain all of the transmission fluid since it has been constantly leaking. I want to reinstall the pan from scratch with new gasket.

I removed the th350 dipstick tube and cleaned up around flange. I had removed both cooling lines to give me more room to manipulate dipstick tube and see if mounting tab would line up to cylinder head correctly.

I get the dipstick tube into the transmission after fighting with the o-ring and every looks good.

I start moving the cooling lines to get them reattached and I am noticing that the upper cooling line is positioned behind the dipstick tube from my position laying on my back looking up.

I am studying the situation and thing that there is no room for me to get a wrench in position to tighten the line. I didn't attempt it, and removed the dipstick tube thinking i could get in reinserted after reattaching cooling line.

I have given up for the night to regroup.

I have removed the oil filter adapter, passenger valve cover, vacuum modulator, and air cleaner try to twist the dipstick into position while keeping it behind the upper cooler line.

I may revert to installing the dipstick first and fighting with the cooler line. I was thinking that i should attach the line first to avoid causing damage from installing blindly.

I have also been tossing around the idea of tilting engine and trans up or down to gain maneuvering space.

At this point I am whipped and with a headache.

[East]

I am going to install the dipstick tube first and get it fastened to the cylinder head where the tube bracket aligns perfectly with the bolt hole.

Someone mention in another post that it was imperative that the bracket aligns perfectly or the tube will be misaligned at the transmission and leak.

[East]

I probably had one of those originally and tossed it out to use a dangling rubber hose between the carb and vacuum modulator so it rests on the hot exhaust and dry rots to allow a vacuum leak. Or that it collects a coating of oil and dirt and decomposes.

It sure gets expensive having been young and dumb. Don't get me wrong. I changed a little: I'm only older now.

I figured that I could bend a hard line from NAPA by copying a picture from a vendor, and fasten it properly to the transmission.

I haven't been under the car for years, and I keep finding things to put back correctly. It feels good emptying that bin of leftover parts I ended up with from my youth.

[East]

I installed the dipstick tube into the transmission first, and then the upper cooler line. It took some time to tighten the upper coolant line because the amount of wrench turns allowed by the space available.

The lower coolant line was much easier to tighten.

I have to attach the the dipstick tube bracket tab to the cylinder head without distorting the angle of the lower tube going into the transmission.

The pictures that I posted were not of my transmission. I found them on the Internet when I was trying to locate the dipstick tube. I was using them as an example of how the dipstick is formed around all of the surrounding components. It's funny that the dipstick that I removed fit with one added bend. Too bad the bend kinked the tube.

I bought an o ring kit for the speedometer. I am going to try one member's suggestion to use two o rings on the vacuum modulator. The only other parts penetrating the transmission case are the detent shaft and the kick down connector.

I have to purchase a good pan gasket. I bought a tube of Permatex Automatic Transmission Gasket Maker. Should I just use the sealer without a gasket?

I have read many posts of members trying to pinpoint transmission leak. From looking at the pan, it looked as though it was at fault, but it was sealed really well. It was hard to remove. As others have stated, the fluid collects around the pan making it seem to be the leak.