POTD- PROJECT OF THE DAY: What Did You Make In Your Shop Today?

Reason the output seal leaks is tail shaft bushing is worn.
 
lordbeezer said:
Reason the output seal leaks is tail shaft bushing is worn.
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Can be.

Can also just be wear in the seal. The yoke has a bit of “freeplay” in order to slide on and off and the seal is exposed to road dirt and grime 24/7.

I’ve replaced just the seal before and leaks stop and don’t return. You could argue that the new seal compensates for a worn output bearing, but I always used to check that when replacing the output seal. Never had to do a bearing. Not saying it can’t be the output bearing, just that I’ve never had a problem with one.

Leaks need to be troubleshot before the cause can be known (and fixed).

I have had one c4 develop a pretty serious leak, but that was because of a cracked case. Seems like 450-odd hp is just a wee bit too much to feed into a stock c4 backed up by a set of slappers, a spool and a set of drag tires…lol.
 
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It's not the output shaft seal... it's leaking from the front...

Like I said, I know where it's leaking from... and I know why...

I am assuming that it is caused by a 'factory defect' in the transmission housing... I just wanted to see if Matt's issue was from the same defect.

-Bear
 
It's leaking from the front drivers side corner at the edge of the pan around the gasket, bottom left near the bell housing in the first pic. I thought it was because of the stripped out bolt, but it leaked with a new gasket (annoyingly into a catch pan that had a crack in it!). My friend tried a couple of times with RTV with no success, I'm guessing because the sealing surface on the transmission has a series of large cast in voids all the way round it (see pic). He's ordered a thicker gasket, so hopefully that works. I reckon he should let me drill and tap for a bolt on the front left corner so the gasket can be compressed more evenly, we'll see. There is no damage to the sealing surface, the pan is flat as he carefully flattened any distortion causing by overtightening by the previous owner (presumably to fix the leak), both surfaces are squeaky clean.

In doing some research I found a lot of threads on various forums asking about leaking C4 transmission pans. The only success I found was a guy who bought a special extra thick cork gasket and spent a couple of days torquing the bolts in a special pattern. Sounds like a pain in the ass.
 
mattthemuppet2 said:
It's leaking from the front drivers side corner at the edge of the pan around the gasket, bottom left near the bell housing in the first pic. I thought it was because of the stripped out bolt, but it leaked with a new gasket (annoyingly into a catch pan that had a crack in it!). My friend tried a couple of times with RTV with no success, I'm guessing because the sealing surface on the transmission has a series of large cast in voids all the way round it (see pic). He's ordered a thicker gasket, so hopefully that works. I reckon he should let me drill and tap for a bolt on the front left corner so the gasket can be compressed more evenly, we'll see. There is no damage to the sealing surface, the pan is flat as he carefully flattened any distortion causing by overtightening by the previous owner (presumably to fix the leak), both surfaces are squeaky clean.

In doing some research I found a lot of threads on various forums asking about leaking C4 transmission pans. The only success I found was a guy who bought a special extra thick cork gasket and spent a couple of days torquing the bolts in a special pattern. Sounds like a pain in the ass.
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Ok, that isn't my issue...

I'll try to keep this short...

On the earlier C4's (maybe all of them, but I have no experience with the later ones, so I don't know) there is what appears to be a redundant seal on the front pump. The pump seats on a paper gasket, but also has a rectangle profile o-ring around the pump body.

It is not really redundant, because there is a tiny hole from the area of the pump bore in the housing between the two seals that goes into the pan area above and to the front of the valve body. I don't know what that hole is for... it doesn't appear to have any purpose unless it is a vent to prevent the air between the seals from becoming pressurized as the transmissoin heats up...

The issue is that the pump bore is big enough to prevent the o-ring from creating a good seal. I have another 'parts' green dot C4, and the pump seals fine in it. There is (going by old memory) about 0.030- 0.040" difference in the bore sizes between the two housings.

The one with the larger bore is one that I removed from a bone-stock '64 sports coupe that I parted out a few years ago. I don't believe it had ever been out of the car before... it just about had to have been machined oversize at the factory. Why would someone bore out the pump bore later anyway? There is no reason to...

So anyway, the fluid seeps up through that tiny hole, then runs out around the pump o-ring into the bellhousing. At one time, I had plugged the hole with silicon... it didn't leak for a couple of years, then started again, so I'm assuming the plug came out.

-Bear
 
The small garage got a good cleaning, i arrange some of the rims that need some refurb over the winter, also the electric motor got its name tag cleaned off and rewired first wrong then right and tested, it work very well. Now my machine shop and big garage are a mess but i'm expecting some free time soon and couple of holidays are on the way so i'll be cleaning them too.
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wachuko said:
I always have told my wife that I do not want to grow old and learn she has had regrets…

You know “I did not do this or that because of you…”

So I made sure she has fulfilled all her dreams… or most ot them anyway…And I have done the same…. We are only in our 50’s so I hope we have many more years to fulfill more dreams/goals…

The me first versus her first, that is all bs for us… we are a couple and sometimes she is first or I am first…. Knowing that at times we each have to work harder is normal…

Her crafts brings her joy…knitting, sewing, embroidery, making this or that…. And she gets that the equivalent for me are tools in the garage…or some vinyl records, or whatever it is that I want to learn next…

I have been blessed with a woman, a partner in life, that it is the best of me…. No relationship is perfect, but knowing that we can work through anything, makes it so…

I should not be drinking when I reply… back to my wine… Cheers!!
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This is a partnership not a "happy wife happy life". A partnership with the right person makes for a happy life for both parties, which is what it should be.

Happy for you.
 
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