1965 small block A904 leak

[65barracudaLA]

I have a pretty bad transmission fluid leak in my '65 Barracuda with a small block and the correct 1965 cable shifted A904. I'm pretty sure later years are different and probably easier to fix. The transmission was fully rebuilt last year with all new gaskets (by someone else). I started the engine for the first time a couple of weeks ago. I cleaned everything with brake clean and looked with my 10 dollar Amazon borescope where it might come from. I didn't have to wait long to see it seeping out. Below you can see it on a screenshot. It's at the bottom of the extension housing gasket where its bolted to the transmission body. I might be just a bolt that needs to be tightened. If you're looking towards the front, it's the bottom right bolt. You can't see the bolt - it appears you can only access the bolt from the inside of the parking lock cable housing.

I would like to confirm that the bolt can only be tightened from within the parking lock cable housing?!

I don't really want to drain all the transmission fluid and find that parking lock cable housing gasket etc. Is there a better fix?

Any ideas welcome!

 

[RustyRatRod]

They are really problematic about leaking around the park cable housing. Are you sure it's coming from the tail housing gasket? That's a terrible picture to get bearings from. I "guess" it's sideways with the bottom being on the left side? I had a 65 with that same transmission for a while and I actually never got it to stop leaking all the way. I slowed it WAY down but there was always a slow drip. But not wanting to drain it to fit it? That like saying "I want to get out of bed without getting up".

 

[Murray]

You could be right but I have never leaks as you describe. Other things in this area are more common. Rear servo pivot shaft "O" ring, park cable housing gasket, park cable "O" ring, pan gasket, rear servo adjuster "O" ring, neutral switch gasket. After cleaning the area, you must blow it off with air to minimize the re-appearance of any latent oil.

 

[65barracudaLA]

I cleaned up everything and it's definitely coming out of the bottom right of the extension housing (see image below).

The question is whether there is a extension housing bolt behind the parking lock cable housing that can not be accessed from the outside?

 

[65barracudaLA]

So I went into the garage, took apart and inspected the nasty, grimy slant 6 A904 of the same year that was in the car before. My initial question is answered - there is no bolt that could be tightened. Appears to be somewhat of a design flaw.

Below you can see where it is seeping out on the small A904 (red dashed line).

I looked in the factory service manual and it says to tighten extension housing bolts to 24 foot pounds - does that also apply to the "sprag bolt" that goes through the park lock cable housing?

OIn the left there's a bolt that goes through the park lock cable housing and on the right there is some pivot, but I don't think that can be tightened:

 

[65barracudaLA]

I'm pretty sure I located the leak in between the extension housing and the transmission case. I started taking apart the slant 6 transmission that I still have laying around and noticed that I should be able to get the extension housing off even with the engine and transmission in the car. I will have to remove the (tti dual) exhaust, which I was trying to avoid, because it was difficult enough to adjust so it wouldn't rub on the body etc. I guess I could just mark the joints so I can put it back just like it is. I haven't been able to find a "new" gasket, but I found a NOS one for 12 bucks on ebay. I absolutely love the old Mopar packaging by the way. However, the material is very thin and I wonder if I should just use it as a template and cut my own gasket out of a better/ thicker material?

 

[junkyardhero]

i wouldn't worry about the thinness of the gasket, but i would absolutely use some type of "modern" sealer or gasket dressing on it. sparingly, of course.

 

[Murray]

The cable itself and the housing also leak at this point.

 

[65barracudaLA]

i wouldn't worry about the thinness of the gasket, but i would absolutely use some type of "modern" sealer or gasket dressing on it. sparingly, of course.

Good point.

 

[65barracudaLA]

The cable itself and the housing also leak at this point.

I cleaned everything and the place where it starts seeping out is the bottom of the extension housing gasket. I used my cheapo borescope to check all around and that was the only place where it came out. And it's not just a little, it's like a quart when the car sits for a few days. The housing of the slant 6 trans appears to be in good shape, so I will probably put a new seal in it and use that one - in case that was part of the problem.

 

[65barracudaLA]

Finally pulled off the extension housing and it turns out the guy who rebuilt the transmission used the wrong gasket and some household silicone?! What an idiot. At least now I'm pretty confident that the new (and correct) gasket will fix the horrible leak.

 

[65barracudaLA]

Here you can clearly see why you can't use the later style gasket on an early A904. There was absolutely nothing stopping the fluid coming out of this hole. I had told the guy numerous times that it was an early, cable shifted A904 and that they are different from the later ones. He even claimed he had a '64 Valiant. I'm also pretty sure he re-used the filter that already has some specs of metal in it after driving the car less than 100 miles after the rebuild.

I like to support small and independent businesses, but in this case it was clearly a mistake.

 

[junkyardhero]

while it sucks donkey balls that you paid good money and the job wasn't done right, and you had to pull the stuff back apart to fix it, it's gotta be of some solace to see the smoking gun. at least now you know for sure!

man, i would be mortified if i'd sent a car out like that. besides be embarrassing, that shows sloppy work.

good work on staying with your hunch and tracking it down. hope the reassembly goes like a breeze!

 

[65barracudaLA]

while it sucks donkey balls that you paid good money and the job wasn't done right, and you had to pull the stuff back apart to fix it, it's gotta be of some solace to see the smoking gun. at least now you know for sure!

man, i would be mortified if i'd sent a car out like that. besides be embarrassing, that shows sloppy work.

good work on staying with your hunch and tracking it down. hope the reassembly goes like a breeze!

Yeah, knowing where the massive leak is coming from and that it wasn't my fault is definitely helping. He technically didn't "send the car out like that", because he only rebuilt it and I picked it up and installed it.

 

[65barracudaLA]

In the interest of fixing everything else I noticed that there are two trans filters with different part numbers for 1965. There's one for V8 and one for slant 6, but that doesn't make a lot of sense to me. I had a slant 6 one laying around, but ended up ordering a V8 one just in case. Once I get it I will compare them. Anyone know the difference?

 

[junkyardhero]

i *think* they're ostensibly the same filter, just one has cut outs for intake/flow.

i vaguely recall a note somewhere along the way that said something along the lines of "cut out here if needed" for [these years]

 

[65barracudaLA]

I got the V8 filter today (bottom). I'd say they are pretty much the same size, thickness etc despite having different part numbers printed on them. The V8 one seems to be made from a different material though. It's not as fuzzy and the color is slightly different, but my guess is that there would be zero issues running the slant 6 filter in a V8 A904.

 

[65barracudaLA]

Ok, I think I finally figured it out. After looking at the gasket, not the filter. The gasket with the part number ending in 8 is for a TF8 aka A727 and the one ending in 6 is for a TF6 aka A904. So it's just listed incorrectly (everywhere), since the A727 was never available in the early A-body.