Transmission oil leak

Hello; I rebuilt my 265 engine in my 56. Installed the the engine and transmission. I don't have the speedometer cable installed yet and have a small transmission leak. Is it normal to have a leak or is there a problem with the transmission?

Hi John , Wheres the leak coming from? on what part of the tranny body? Bellhousing, ? side plates? and no, nothing should come out of the speedo drive without the cable connected, but all cast iron, ( I guess thats what tranny we are talking about) leak a few drops from the outer speedo cable,

Johnny, the car is just sitting as I'm doing other work on it. The cable connection leaks leaving a small puddle on the floor. THANKS

Johnny, the car is just sitting as I'm doing other work on it. The cable connection leaks leaving a small puddle on the floor. THANKS

Hi John, ok, first of all, you did not reply,,,, is it a cast iron PowerGlide box? if so, when you say the cable connection leaks, is the speedo cable connected to the gearbox? or is the fluid coming from the speedo drive assy, the screw connection that the cable screws on to? there is a rubber „O“ Ring that fits behind the speedo drive that fits into the gearbox extension case, if this is missing the fluid will run out all the time, give me more details please, Johnny

Johnny, I have a standard cast iron powerglide transmission. Came out of a running low milage car. The speedometer cable is not installed. The leak is coming from where the speedo cable would connect. (The threaded port.). Thanks

YOU WILL GET A LEAK FROM WHERE THE SPEEDO CABLE GOES IF THE CABLE IS NOT INSTALLED. THE CABLE SHOULD BE INSTALL TO PREVENT ANY FURTHER LEAKS.

Hi John sorry about delay in talking to you, ok here are the facts, I have the same car/ and Powerglide gearbox as you and I have stripped down loads in my 35 years in the motor trade. The back section of the gearbox only contains the rear bearing and the speedo drive, so its not under fluid pressure as is the main part of the box, the back section is fed with an oil spray from the suction pipe from the main pump, it covers the back bearing and a light splash of oil to the speedo drive gear, the speedo drive is a tube with an „o“ ring seal to stop any fluid escaping from the side of the TUBE! only a slight amount of oil is allowed to travel down the drive tube, just enough to oil the speedo cable, the oil then drains BACK in to the box via a hole in the bottom of the casing back to the main part of the box, so the fluid cannot leak from the box if the speedo cable is not connected, as not enough oil is in the bottom of the box, it might just drip, say a tea spoonful over a few days then it will stop, now if the „o“ ring on the drive tube is missing or damaged it will leak, but only when the pumps being driven, none when stationary with the engine not running, now if that sump hole is blocked then the oil can back up, and it will leak oil, but the clue to that happening is the back extension oil seal will not cope with a massive amount of oil not being allowed to return to the box, and the back seal where the prop goes into will pump out oil! now you dont have that problem , so remove the speedo drive, only one bolt, and it slides out, look at the „o“ ring, to see if its damaged, and how much oil comes out from the hole where the drive came out, it should only be a very small amount, if any, so to sum up, no fluid can come out of the speedo drive assy if the outer cable is not connected, the fluid is lower that the speedo drive at standstill with the motor not running. also its impossible for oil to get past the speedo screw drive, from inside the box, just a few drips maybe, but thats all, so how much is coming out whilst the cars standing in your garage, and look carefully as to where its running down from. Regards John

Johnny; THANKS alot. That's the best explanation I've ever heard. Will check the O ring.

Hi John any news, on the leak?? Regards Johnny G

Johnny; Won't get time to work on it for a few weeks. Thanks

Hi John, Ok keep in touch, and les us know how you get on, have a Happy Christmas and a healthy New year, Johnny G from the frozen stiff UK!

I have a 55 bel air original trans case. i have a small leak that looks like its coming from the back of the oil pan. i power washed both pans to clean all run down and dirt and grime build up to see exactly where its leaking.

Turbine o-ring,or turbine oil seal leak,if it not engine oil.

Where would that be located?

Hi Jonathan,You must remove engine,or transmission out of car,then you can inspect both seals (usually taking engine out of car is easier way).Turbine/con­verter o-ring location is between converter primary cover and primary housing,and oil seal is under converter („neck“ seal),when you take converter out of transmission.Both seals are available many places under 15$.But first be shure it's transmission oil,and leak is inside turbine housing,you can check that removing oil plug UNDER converter housing,(must be dry inside,that is chek hole)do not remove other smaller horizontal plug,there is transmission oil inside.

Sorry,i automa­tically guess it's powerglide trans?

Every thing including the transmission is original and its dripping down the side of the transmission case in the back where the shifters are

Ok,maybe shifter oil seal,or mounting bolt loose.There is oil behind the one or two side mounting bolt(can't remember precicely).If you have powerglide trans?

there is one mounting screw that is connected to a rubber mount its leaking from that braket and only that brakect nothing on top of the transmission or on the side just there and runs down