leak at speedometer adapter 56 bird

ron56

ron56

Active Member
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Mar 17, 2020
Thunderbird Year
1956
I have a small leak at the speedometer angle drive adapter. It's on a 1956 bird with the automatic transmission. It is on the end opposite of the speedo cable. Mine appears to have a 1/8 pipe plug in the middle of a piece that doesn't tighten it just turns. Any ideas on why it leaks there and what the fix is?
 

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It has been many many years since I worked on that vintage, most were similar no matter make or model, but if the speedometer cable adaptor can be removed from the transmission, there is usually an o-ring located on the adaptor that provides the seal. Remove the adaptor, replace the o-ring and reinstall the adaptor. I apologize I am working from very old memory.
 
I have a small leak at the speedometer angle drive adapter. It's on a 1956 bird with the automatic transmission. It is on the end opposite of the speedo cable. Mine appears to have a 1/8 pipe plug in the middle of a piece that doesn't tighten it just turns. Any ideas on why it leaks there and what the fix is?
Here is a picture of the speedometer angle drive adapter that you are referring to. In the picture you can see the o-ring that 05Dave is talking about. From what you are saying the leak is coming from angle drive adapter itself and not the o-ring seal. Either way the angle drive adapter will have to be removed from the transmission.

doug7740
1955 Thunderbird Blue
100_6537.JPG
 
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Yes, the adapter is leaking from the metal piece that is shown by the picture that doug7740 posted. You can see the end of the adapter that I'm talking about it has the square fitting which is a 1/8 pipe plug. If I try and tighten it by turning the square plug the whole metal piece that plugs that end of the adapter just spins. Has anyone had the adapter apart and if so what does secure that metal plug that the 1/8 pipe plug screws into? I don't think that it should freely turn. I had the adapter out when I overhauled the trans and if I remember it didn't look like it would come apart seemed it was crimped. It's not a cheap part to replace.
 
I did find the replacement part on line for $381.00 but no drawing or pictures of the internals of the old one. I have never dismantled that part on any make, so can not give guidance on how to begin or if it is possible to dismantle and repair internals, or what to expect once you take it apart other than you may have committed to buying a replacement. The picture looks like the main housing is a pot metal casting so may be a press fit and not designed to be repairable. Depends on how knowledgeable you are with similar
creations and how bad you want to fix the leak. You do want to have reliability so as long as you can buy a new one you only have money to lose. Sorry I could not be of more help.
 
Good idea Bond007 I didn't have any FlexSeal so I used some leftover plastic JB Weld from repairing my arm rests around the metal plug and that so far seems to have worked. Anyone have any idea why the angle drive has that 1/8 in pipe plug on the end?
 
Good idea Bond007 I didn't have any FlexSeal so I used some leftover plastic JB Weld from repairing my arm rests around the metal plug and that so far seems to have worked. Anyone have any idea why the angle drive has that 1/8 in pipe plug on the end?

That is actually a miniature gear drive so it does need lube, the plug would be a way of providing that. Is the leak actual transmission fluid or some other oil type fluid? If not transmission fluid, then all the lube you have left is what is in there now, but you could judge that from the size of the leak on the garage floor and the length of time it has been leaking. I always liked old airplane repair manuals from that same time period, they gave full visual and written break down of the little systems - I owned a 1958 Piper Apache for 26 years, I could just look in the book! And the books are still available. I wonder if Ford ever provided a drawing.
 
It is trans fluid that was leaking from the drive. I'm puzzled by a couple of facts: I checked the Ford manual and a other source that shows the maintenance items and no mention of lube for the drive. I also saw a picture from one of the suppliers where the drive doesn't have the plug. I agree you would think the plug would be to lube the drive. When I had my trans apart I changed out the gear to get the speedometer closer to the correct mph. At that time I packed the drive gear set (right angle) with grease. I don't remember anything in the way of seals to keep trans fluid out of the drive. Only the o'ring to stop leaks to the outside of the drive.
 
It is trans fluid that was leaking from the drive. I'm puzzled by a couple of facts: I checked the Ford manual and a other source that shows the maintenance items and no mention of lube for the drive. I also saw a picture from one of the suppliers where the drive doesn't have the plug. I agree you would think the plug would be to lube the drive. When I had my trans apart I changed out the gear to get the speedometer closer to the correct mph. At that time I packed the drive gear set (right angle) with grease. I don't remember anything in the way of seals to keep trans fluid out of the drive. Only the o'ring to stop leaks to the outside of the drive.
You have answered just about any point I can think of. The small pipe plug would not allow much access for any maintenance purpose. As long as you can keep the transmission fluid in, you are home free. If what you are using fails you could try a good layer of epoxy after a through cleaning.
 
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