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Now you need to take off the ST-10 front bearing retainer with the seal and replace it with the correct early T-10 front bearing retainer without the seal...
Early T-10 transmissions are vented thru the front bearing retainer, with the seal the trans builds pressure inside, and it has to go some where...
Or vent the case like a ST-10, above the side cover...
Drain Surgeon77,
You are the bomb. When I first red your statement it took me a few seconds to digest. But you are so correct probably the reason I am having the leaks is because of the front seal and no venting, consequently pressure building up. I just spoke to my friend that did the restoration and is repairing the leaks and sure enough we do not have the transmission vented. When I discussed it with him what you said we both realized that yes it is not vented and you make a lot of sense. We do not want to eliminate the ST10 front bearing retainer with the seal so we are going to look into venting above the side cover as you suggest like the ST10.
Thank you so much I am sooooo appreciative of your observation. It is probably going to save hours of agony trying to fix the symptoms, leaks, without fixing the root cause.
You can buy a screw in case vent and drill/tap the case to install it. I did one recently on a toploader. Installed it in the top of the tail housing where there is less lubricant spray and churning.
Any one knows where I can get an original ST10 vent tube? or an equivalent metal tube. I have been doing searches and can not find an original ST10 or anything similar. There is a Dorman plastic one but that looks too flimsy. I will like to use an original if I can or a metal one.
DansYellow 66 which one did you use and is it working? No oil coming out of the tube?
Well, so far I can't find where I purchased it from. Here is a shot of it - mounted on the forward part of the tail housing. I haven't noticed any leaking of fluid from it. I know it took a 1/4"NPT-18 tap for the threads.
I will look some more tomorrow and see if I can find the receipt.
Last edited by DansYellow66; 11-29-2018 at 10:47 AM.
DansYellow66 The Muncie Transmission has the breather vent tube in the tail housing just like what you did. The Muncie Breather vent part number is FV102. I did find a 55 to 64 Chevy Rear Axle housing Differential vent that is very close to the ST10 breather vent tube. The OD are the same 3/8 " OD but the lenght is 1/2 " shorter. The one I got is 3/4 " long from the ring shoulder to the tip. The Transmission one is 11/4" long. I do not know the transmission wall thickens where the breather goes. If it is 1/4 " thick then the one I got will protrude 1/2" instead of 1 " for the other one. I think it will still work but I welcome inputs.
You can see how much the vent tube protrudes from the wall into the transmission if the wall is 1/4" thick Muncie with Breather vent tube on the tail housing
I don't think it's long enough to get into the output shaft - but you could always take a bit of the angle extension off of it. I don't think there is near as much issue with transmission fluid working it's way out when installed in the tail housing since except for reverse there aren't a lot of gears in there throwing oil all around. I don't see a hex section on that one so I guess it would have to be tightened with some channel locks or similar. Maybe a bit of blue locktite would help secure and seal it with minimal torque.
I don't think it's long enough to get into the output shaft - but you could always take a bit of the angle extension off of it. I don't think there is near as much issue with transmission fluid working it's way out when installed in the tail housing since except for reverse there aren't a lot of gears in there throwing oil all around. I don't see a hex section on that one so I guess it would have to be tightened with some channel locks or similar. Maybe a bit of blue locktite would help secure and seal it with minimal torque.
I do not know yet where I am going to put the breather. If I use the one I bought, the photo above , then it will be in the main case above the side plate like the Super T10. If I go your way it will then be in the tail housing and I will use a breather like the one you posted from Amazon or I will use the Muncie FV102. Let me know if you find the info.
I want to thank you all for your help and your patience with my posting. I have to say that the problem is solved thanks to all of you. The root cause of the problem was the transmission venting. When we modified the T10 to incorporate the Super T10 Front bearing housing with a seal we did not realized that the T10 vents through the front bearing retainer. Drain Surgeon 77 observation was dead on and pin pointed the root cause. No doubt he is going to save me a lot of agony and pain because if I had not fix the vent it will continue to leak without any doubt no matter how good I plugged the leaks.
So here is what we did:
Drilled a hole in the transmission above the side cover like the ST10 does and like Eric suggested. We then installed a Breather Vent tube like the original ST10. The Vent tube was very difficult to find but ZIP Corvette has it Part Number TM-301. The vent tube has rings that look like threads, but they are not they are compression rings. We used a 23/64 in drill bit to drill the hole, the body of the vent is 3/8 in. Then we used red Loctite on the compression rings and tapped the vent into the hole.
For the reverse idler gear shaft we followed the advise of all of you guys. Permatex Ultra Black then the Welch plug tapped in. The welch plug was very difficult to find as it is 1 1/8 in diameter, and looks like not a very common size. After much searching I found it practically next door , NAPA has it. The NAPA part number is 3811010. I bought five just in case. If anyone needs one let me know I will send you one.
The countershaft we used Permatex Ultra Black.
We have driven the car for about 30 miles and not a drop of transmission oil is seen. Of course it is too early to claim total victory but I am very confident the we have addressed the problem and fixed it.
A big thank you to all of you
Congratulations. Don't be disappointed if you eventually see a drop or two from somewhere. Trying to seal these old cars up tight is just about impossible.
Dans,
I know what you mean, I have been chasing the transmission leak and the oil pan leak for months. The transmission looks like the fixes will do it. Now that it is vented there is no pressure built up and the shafts have been sealed well. The oil pan has been leaking through the front on the smile. It has also been a major headache. We finally took out the oil pan replaced the gasket with a new one, OS-34510-T and applied Permatex super black to the bottom of the timing chain cover and the oil pan, that is on both sides of the gasket on the smile. of course the Permatex was also applied at the front corners. We had used a 34510-T before but we did not use the Permatex on both sides of the smile. There is a posting on this problem and it was finally fixed with the rubber gasket with Permatex on both sides. So far no leaks on the oil pan.
11-26-2018, 05:29 PM
